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rds_storyboard by chenmeixiu

VIEWS: 15 PAGES: 36

									MSG-CAL
Module development
RDS (Rapid Developing Systems)


                                             Storyboard

Version 14 April 2002

Warnings :
 the texts are not proof-read. They will at a next stage by a native speaker.


                                                                                             Foreword


This storyboard has been selected amongst three approaches by colleagues of UKMO, FMI and
Météo-France.

The training module is based on a METEOSAT case study (Vaison la Romaine, 22 September 1992)
concerning a MCS rapid development. The learner will try to identify missing information which could
have improved the nowcasting.

In comparison, the new features of MSG will be presented through a couple of case studies.

The screen equivalent is given for a web version of the module

                                                                                      Technical spec.

       Screen size 1024x768

                                                                                Learner prerequisites

   Good knowledge of the use of current Meteosat channels.
   Skills in forecasting and nowcasting.

                                                                                             Objectives

   Get a knowledge of the added value brought by additional MSG channels and features for short
    range forecasting and nowcasting of RDS
   Observe the impact of rapid scan on RDS early detection and follow-up
   Know how to use SAF products for RDS short term forecasting
MSG-CAL
Module development
RDS (Rapid Developing Systems)




                Rapid Developing Storms (RDS)

Unit of study 1 – What happened at Vaison la
Romaine
Learning objectives: Understand the vital importance of nowcasting

Activity
        Environment
                Knowledge object (ref-lib : article.html)
                                                       th
                “Le Monde” Newspaper report of the 24 September 1992 [to be translated into
                English (Adelink)]
        Activity
                Knowledge object (intro.xml)

               Video mpeg showing the flood


               During the late morning of 22 September 1992, several mesoscale convective
               systems generated a flash flood in and around the city of Vaison-La-Romaine, France,
               in the southern foothills of the Alps not far from the Mediterranean coast. 35 fatalities
               occurred, hundreds of houses were destroyed, and property damage was estimated at
               nearly one billion euros.

               The “Le Monde” (French newspaper) article reports the event on the same day and
               notices that it was totally unexpected. People involved in public safety (firemen,
               medical doctors), were themselves trapped by this flash flood.

               When such a violent and extreme phenomenon occurs, it is obvious that every minute
               counts to raise alarm.

               The communication chain, which allow meteorologists to quickly alert the emergency
               services, and then the citizens, plays an important role. Several meteorological
               services, amongst them Météo-France, work on optimising this concept, to ensure that
               short term forecasts are correctly transmitted, in real time, to the population.

               Nevertheless, the forecaster must detect “upstream” as early as possible the intensity
               and location of dangerous phenomena.

               Amongst the tool set available to forecasters, MSG data will provide them with more
               frequent images in several channels, with a better resolution that the Meteosat first
               generation images. In nominal service, the 15‟ frequency over Europe, a better
               resolution, may allow to raise alarm a bit earlier, and to focus on other sources (radar
               data for instance) to gain several precious minutes to alerte emergency services and
               other public bodies.
MSG-CAL
Module development
RDS (Rapid Developing Systems)




Unit of Study 3a – Presentation of the
meteorological background of the Vaison la
Romaine case study. Synoptics


Prerequisites: experience in forecasting

Activity
        Environment
               Knowledge object (activity – intro)
                     Title: Rainfall to a depth of 300 mm in 24 h
                     Text: Several convective systems produced 300 mm of rain in 24 h , with 220
                     mm occurring in 3 h near the city of Vaison-La-Romaine (red V on the figure).
                     Surrounding areas also recorded intense precipitation (224 mm in 3.5 h in
                     Barnas, Ardèche, some 90 km away) but reported less major damage. It has
                     been stated by Benech et al. (1993) that over a 30 year period in France a
                     rainfall amount of over 300 mm has occured on only 15 occasions during the
                     later half of the year, and the amount measured in Vaison-La-Romaine (179
                     mm in 2 h) is estimated to occur once every 40 to 150 years, depending on
                     various assumptions.

                       Image: fig2cl.jpg
                       Legend : 24h rain accumulations for 22 September 1992 (in mm, beginning at
                       0600 UTC 22 September). Labels oriented N-S are ground elevations, with
                       contours in light grey.

               Knowledge object - reflib (geography)

                       Title: Geography and topography of the event area
                       Text: The city of Vaison-La-Romaine is located in the southern foothills of the
                       Alps not far from the Mediterranean coast bounded by the Gulf of Lyon. The
                       orography of the southern part of France is characterised by the Pyrénées
                       mountains to the west, the Massif Central to the north and the Alps to the
                       north east. The Rhône valley is orientated north to south and lies between the
                       latter two mountain ranges.
                       image: fig1map.gif
                       Legend: Topography of western Europe: topography is shown by the colour
                       bar with low altitudes in blue and high altitudes in red.

               Knowledge object –ref (external URL) :

               MCS conceptual models ZAMG
               http://www.zamg.ac.at/docu/satmanu3.0/manual/satmanu/manual/Cb/cb0.htm


               Knowledge object – reflib - sounding
                     Title : Vertical structure Relevant environmental soundings
                     Image : fig6a.jpg fig6b.jpg
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                      Legends : Soundings at two locations : Palma de Majorca (a) and Nîmes (/b)
                      or 0000 UTC 22 September. Inserts are hodographs with axes labeled in m s-
                      1 and heights in thousands of m. The sounding in Palma de Majorca, located
                      upstream of the flood, was representative of the advected flow.

                      Text : Palma sounding analysis

                      This sounding is of the loaded-gun type with a moist, shallow marine layer
                      showing weak static stability, capped by a strong temperature inversion and a
                      dry neutral warm layer (extending from 900 to 630 hPa). This dry layer
                      originated from the high terrain over North Africa and travelled through only
                      subsiding or slightly ascending regions. The upper layer, from 630 hPa
                      upward, was more moist and, from 480 hPa upward, stable for moist ascent.
                      The overall convective potential for this sounding can be scaled by the large
                      amount of Convective Available Potential Energy (CAPE) which reached
                      2662 J kg-1 for a parcel rising from the surface.
                      The vertical wind shear was low (7 m s-1).
                      The precipitable water in the lowest 150 hPa layer amounted to 16.7 mm,
                      and to 30.2 mm from the surface to 500 hPa.

                      Nimes sounding analysis and comparison to climatology

                      An elevated capping layer (from 750 to 600 hPa) was present. A virtual
                      potential temperature analysis shows that the layer extending from 700 to 570
                      hPa was dry adiabatic. A very dry layer extended upwards from 570 hPa.
                      The CAPE reached 383 J kg-1. In order to put this value in perspective,
                      because it is low with respect to values encountered in the Midwest of the
                      United States during heavy convective activity, a climatology of CAPE values
                      was computed for a 28 year period for September morning soundings in
                      Nimes. For 706 cases, the mean value is 96 J kg-1 and this case ranks in the
                      upper 8% of the distribution. A CAPE was computed using the Nimes
                      midnight sounding, but using for the rising parcel surface characteristics from
                      a ground station located near the coast and at a time when diurnal heating
                      has already begun but before convective systems have swept the coast. The
                      Montpellier station was therefore chosen at 0700 UTC. This gave a much
                      more significant CAPE value of 2452 J kg-1.
                      The low-level (150 hPa) precipitable water content of 12.4 mm ranks in the
                      upper third of a 12 year September climatology, while the content for the
                      surface to 500 hPa layer is significantly high at 30.6 mm (i.e., in the upper
                      12%). The wind hodograph showed a clockwise turning of the wind with
                      height, which is favorable for organized convection.

              Knowledge object –reflib -vertstruc
                    Title : Vertical structure along a cross-section at 0000 UTC 22 September
                    Text : This vertical cross-section from the north west of Spain to the south
                    east of the Balearic Islands is crossing a pseudo-frontal zone associated with
                    a thermal gradient to the south east of the cutoff low. It demonstrates the
                    following :
                    i) the cold air mass is partly hanging over the moist and warm advection along
                    the Spanish coast and slightly west of it, at the 600 hPa level;
                    ii) conditional instability is occurring over the entire Mediterranean part of the
                    cross-section;
                    iii) this instability is mitigated around the Spanish coast by the already
                    developed convection.
                    Image : fig7.gif
                    legend: Cross section, as derived from the Peridot model analysis, along the
                    line overlayed on the second 500 hPa field displayed on the on the 500 hPa
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                      animation. Black lines represent potential temperatures (in K, at 4 K intervals).
                      Dark green lines are equivalent potential temperatures (in K, at 2.5 K
                      intervals). Pink lines indicate humidity above 60 % (at15% intervals). SpC
                      signifies Spanish Mediterranean coast.

              Knowledge object - reflib – surface.xml
                    Title : Surface analysis
                    Image : fig31.jpg
                    legend: A Météo-France official surface analysis for 1200 UTC 21 September
                    1992 is shown. The mean sea level pressure field showed a 1000-hPa low,
                    centred off the western coast of France. The frontal analysis showed a small-
                    scale pseudo kind of front drawn around the cutoff low on its eastern side, with
                    a limited warm sector, and a small secondary cold front to the west.
                    Convective activity was already occurring near the Mediterranean coast of
                    France, as represented by a cold front aloft (i.e. open triangles), which caused
                    soil saturation and played a role in the subsequent flooding.
                    Image : fig32.jpg
                    legend: Analysis of mean sea level pressure (solid line at 2-hPa intervals),
                    pseudo wet bulb potential temperatures (dashed line at 2°C intervals), and
                    wind barbs for 0600 UTC 22 September. This figure illustrates, for that time,
                    the sharp gradient in the pseudo wet-bulb potential temperature field
                    associated with the pseudo cold front along the eastern Spanish coast and
                    extending into southern France. This gradient zone was also clearly
                    delimiting different wind orientations. Later the cold front zone showed a slow
                    eastward movement, and it reached Italy late in the following night, still with
                    active convection ahead of it.

                      An other noticeable feature is the mesoscale low centered over the
                      French Mediterranean coast. It was situated between a weak ridge
                      associated with the cold front, insouth western France, and a marked
                      ridge in the eastern part of the area established by the Alpsand blocking
                      the easterly flow. This low drove a nearly steady, warm (around 22°C) and
                      nearly saturated, southerly to southeasterly flow into the Mediterranean coast,
                      with speeds reaching 20 ms-1. The channelling effects of the Spanish plateau,
                      the Pyrennean and Alpine ranges, and the Massif Central helped generate a
                      low-level jet in the Gulf of Lyon.


              Activity : 500 hPa analysis. Anim1.xml (animator with quiz)
                      Comment: Three successive 12 h spaced 500 hPa field analyses are
                      displayed from 21 September to 1200 UTC on the 22 September 1200 UTC.
                      Contours of geopotential are shown in black solid lines (interval - 40 m), while
                      temperatures are shown in colour. Try to identify the main characteristics of
                      the mass and temperature fields evolution. This is important in understanding
                      what happened in the South East part of France.
                      General question:
                      Try to identify the main characteristics of the mass and temperature fields
                      evolution. This is important in understanding what happened in the south east
                      part of France. Click on the answers which seem appropriate
                      Answer 1 : A large-sized trough containing a cutoff low was reaching the
                      French Atlantic coast. Between 21 September 1200 UTC and 22 September
                      0000 UTC the cold temperatures field shifted southward
                      with respect to the mass field
                      Feedback 1: Yes, this was a main characteristic of the mass field evolution.
                      One other specific point was also important
                      Answer 2 : A meridional ridge was moving eastwards towards central Europe.
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                     Feedback 2: Not precisely. The large meridional trough over central Europe
                     was also moving northward, accompanied by a large warm advection over
                     northern Europe.
                     Answer 3: Some evidence of small-scale cold advection appeared in thermal
                     short waves developing in front of a large tilting trough.
                     Feedback 3: Yes. This was important in determining what happened near the
                     French Mediterranean coast. One other main feature characterized the
                     situation.
                     Image1 fig4syn1.jpg
                     Image2 fig4syn2.jpg
                     Image3 fig4syn3.jpg
                     Particular question to image 3
                     Where were there some indices of small-scale cold advection?
                     Answer1: Northward in the central part of Spain
                     Feeback1: No. In that area, the isobars were nearly parallel to the isotherms,
                     so there is no clear temperature advection.
                     Answer 2: Over the Gulf of Lyon ner the French Mediterranean coast.
                     Feedback 2: Yes. A thermal short wave induced small-scale cold advection.
                     Answer 3: Over the North West part of Spain (Cap Finisterre).
                     Feedback 3: No. Over this area there were indices of warm advection.

              Activity : Jet streaks and vertical velocity fields. Anim2.xml (animator with quiz)
                      Comment: Three successive 12 h spaced Peridot model field analyses are
                      displayed from 21 September 1200 UTC to 22 September 1200 UTC. Jet
                      streaks are shaded green above 35 ms-1 and labelled in ms-1. Vertical
                      velocities at 400 hPa are represented by thin contours at 5 cm-1 intervals.
                      Upward motions are in dashed lines and shaded red; subsidence areas are in
                      continuous lines and shaded blue above 10cm s-1.

                     Examine how the pattern of the jet streaks evolved during 24 h. Look at
                     the effects on the vertical velocity field caused by both influences:
                     orography and jet streaks configuration.

                     General question:
                     How could you characterize the evolution of the jet streaks pattern during
                     these 24 h?
                     Answer 1 : An eastward displacement by the translation of a stationary jet
                     streak pattern.
                     Feedback 1: Not at all. Look more closely at the three steps of the evolution.
                     Answer 2 : A decreasing of the jet intensity combined with an eastward
                     displacement.
                     Feedback 2: No. The jet intensity maximum was lightly decreasing, but there
                     was not just an eastward displacement caused by a motion of translation.
                     Answer 3: A rapid change in the jet streaks pattern which rotated around the
                     eastward moving trough.
                     Feedback 3: Yes, you are right. Because of that rotation the jet axis direction
                     was completely reversed in 24 h, and the jet curved considerably during an
                     intermediate stage.
                     Image1 fig51.jpg
                     Image2 fig52.jpg
                     Image3 fig53.jpg
                     Particular question to image 2
                     Looking at the dipole of vertical velocities which appeared around the
                     Pyrénées, do you think it was mainly driven by the Pyrénées mountains?
                     Answer1: Yes, mainly.
                     Feeback1: You are right. The strong subsidence on the northern side of the
                     Pyrénées and the upward velocity on their south eastern side seem consistent
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                     with windward ascent and leeward descent, as far as the airflow could be
                     deduced from the jet pattern and the 500 hPa mass field.
                     Answer 2: No.
                     Feedback 2: You are wrong. Such strong subsidence on the northern side of
                     the Pyrénées would have been difficult to explain without a strong orographic
                     effect. Try again.
                     Particular question to image 3
                     Which factors would have played a role in driving the vertical velocity near the
                     flood area (marked with a cross (x)),around 1200 UTC ?
                     Answer1: The right entrance of a jet streak
                     Feeback1: The flood area is well located under the right entrance of a jet
                     streak, which is favourable for lifting, but another factor could be
                     mentioned here.
                     Answer 2: The lifting by orographic effect.
                     Feedback 2: The flood area was located almost windward of the main
                     mountain ranges (Alps and Massif Central). This was favourable for
                     orographic lifting but another effect could have played a role.
                     Answer 3: Both.
                     Feedback 3: Yes, you are right. The flood area was well located on a place
                     where these two factors may have played a role; under the right entrance of a
                     jet streak and nearly windward the main mountain ranges (Alps and Massif
                     Central).

              Activity : Large scale cloud patterns – Anim3.xml (animator with quiz)

                     Comment: Ten infrared Meteosat images are displayed. They are roughly 3 h
                     spaced except when some data were missing. The numbers in the second
                     box at the bottom indicate the daynumber and the UTC time.

                     By playing the animation try to track the main cloud signatures associated
                     with the synoptic situation: the clouds associated with the center of the cutoff
                     low;
                     - the clouds associated with the cold front drawn on the 1200 UTC 21
                     September surface analysis;
                     - the areas prone to convective developments.

                     General question: How could you characterize the developments of the deep
                     convective systems?
                     Answer 1 : The developments of the deep convective systems were chaotic
                     and mainly driven by the diurnal heating cycle.
                     Feedback 1: No. The development of deep convective systems had some
                     kind of organization in a belt moving eastward. The diurnal heating cycle was
                     not the leading factor, some convective systems developed during the night or
                     the early morning.
                     Answer 2 : The deep convective systems developed in a convective belt
                     preceding the surface cold frontal zone, oriented from south to north and
                     moving eastward. Three different phases could be roughly distinguished
                     during the
                     animation period :
                     -Phase 1 = images 1 to 3 (1530 UTC to 2130 UTC the 21 September)
                     -Phase 2 = images 4 to 6 (0130 UTC to 0530 UTC the 22 September)
                     -Phase 3 = images 7 to 9 (0930 UTC to 1530 UTC the 22 September)
                     Feedback 2: Yes. We can roughly distinguish these 3 phases:§
                     - during phase 1, the convective developments occured relatively far away
                     from the frontal zone over the southern part of France and eastern part of
                     Spain, they seemed to be influenced by the diurnal heating cycle;§
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                     - during phase 2, several deep convective systems were activated in the
                     southern part of the belt when it was crossing the Spanish Mediterranean
                     coast and came over the warm sea of the Gulf of Lyon;§
                     - during phase 3, major mesoscale convective systems developed over the
                         south eastern part of France. It was remarkable that they became more
                         active (cold cloud top temperatures) when some cloud elements, perhaps
                         associated with the surface cold front, overtook the convective belt and
                         merged with it."

                     Images lgscal1 to 10.jpg

                     Particular question to image 1 : Which cloud feature was associated with
                     the cutoff low center on this image? By tracking this feature in the following
                     images what could you deduce about the evolution of this low?
                     Answer1: A small coma cloud. The further evolution gave some indication that
                     the low was becoming less organized and filling.
                     Feeback1: Yes, you are right. After growing on the next image the coma cloud
                     has been slit into several small clusters. It was an indication that the low was
                     becoming less organized and filling.
                     Answer 2:. An open cell becoming a squall line. It was an indication that the
                     low was deepening.
                     Feedback 2: No, sorry. This answer does not correspond to the reality. The
                     cloud signature on this image in the center of the low is characteristic of a
                     small coma cloud and not of an open cell.

                     Particular question to image 9: Which characteristic feature could you
                     recognize on the main convective system present on this image?

                     Answer1: A coma-shaped convective cloud.
                     Feeback1: No. This is not the characteristic shape of a coma cloud.
                     Answer 2:. A V-shaped wedge of cloud.
                     Feedback 2: Yes, you are right. This V-shaped wedge is a characteristic
                     shape of some severe or quasistationary convective systems occuring with
                     strong high level winds.
                     Answer 3: Overshooting tops.
                     Feedback 3: There are likely overshooting tops in this deep convective
                     system, but grey scale contrast is not enhanced enough to clearly identify
                     them.

              Activity – summary.xml
                      Title : Summary of the synoptic environment
                      Text : This schematic summarizes some key features of the synoptic situation
                      at 0000 UTC which played a leading role during the early morning of 22
                      September.
                      At low levels a southerly flow of warm and nearly saturated air passed along
                      the Spanish Mediterranean coast towards the southern part of France.
                      At higher levels (500 hPa) a temperature trough was approaching from the
                      west, turning around the cutoff low.
                      It was overhung by a curved high level jet. Its northern branch was moving
                      eastward and growing stronger.
                      Image : 800hpa.jpg
                      legend: Sketch of the synoptic environment on 22 Sepember at 0000 UTC.
                      - Arrows represent the wind field at 800 hPa.
                      - In red are overlayed some warmest 800 hPa equivalent potential
                      temperature isopleths (spaced every 2.5 K)
                      - In green is sketched the 500 hPa temperature trough axis.
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                      - Blue filled areas represent the high level jet where the wind
                      speed exceeded 40 m/s.




Unit of Study 3b – Presentation of the
meteorological background of the Vaison la
Romaine case study. Mesoscale.
Activity – Mesoscale analysis

       Environment

              Activity : Mesoscale surface field analysis anim1.xml

                      Text: Objective mesoscale surface field analyses were performed using a
                      cubic spline analysis of surface observations issued from the conventional and
                      automated ground station networks. By visualizing these hourly fields with
                      superimposed radar reflectivities we suggest you observe how these fields
                      have evolved in relation to the precipitating systems, with special attention to
                      identifying cold outflows and meso-highs generated by these systems.
                      Composite images from three radars are superimposed over mesoscale
                      surface field analyses. Purple continuous lines are contours of the analysed
                      sea level pressure field (in hPa at 1-hPa intervals). Dashed green lines
                      represent surface potential temperature contours (in °C at 2° intervals). 10 m
                      high winds are represented in red with conventional barbs. Two elevation
                      contours (at 300 and 900 m) show in black solid lines.

                      Image: fig11_1.jpg
                      Legend: The time: 0600 UTC on 22 September. South easterly surface winds
                      were relatively strong along the Mediterranean coast. An area of warm
                      air laid at the north of Vaison, and a small cold pool was associated with
                      the cold outflow of a convective system (labelled QLin further summary) that
                      remained almost stationary along the Massif Central foothills fromearly in the
                      morning to 0900 UTC.

                      Image: fig11_2.jpg
                      Legend: At 0800 UTC the mesoscale low was slowly deepening and moving
                      eastwards. The convective line, presented previously as a possible squall line,
                      was propagating north eastward.

                      Image: fig11_3.jpg
                      Legend: By 0900 UTC the convective line has moved north eastward. A large
                      cold pool lay just behind the line (it has merged with system QLs outflow) and
                      a meso-high appeared on its south eastern edge under heavy precipitation.
                      Despitethis, it is not very easy to see the lines on this drawing. These
                      signatures when combined with characteristic surface observation diagrams
                      give very clear confirmation that the convective line is a squall line (labelled
                      SL).

                      Image: fig11_4.jpg
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                      Legend: By 1000 UTC the squall line was dissipating. It has pushed away the
                      warm air which was lying north eastward of Vaison. The cold pool
                      generated by the line led to the development of a cold wedge in the
                      Rhône valley funnel. New convective cells developed at the southern part of
                      this wedge. The northern one moved quickly northward (look at the detailed
                      tracking of the convective systems evolution; sequence 1); it has been
                      labelled SC because it had some similarities with a supercell.

                      Image: fig11_5.jpg
                      Legend: At 1100 UTC the continuous generation of new cells along the
                      leading edge of the strengthening cold wedge led to the building of a
                      stationary convective line (labelled SCL) in the south of Vaison.A convective
                      line appeared in the north west and this was assimilated as a frontal line
                      (labelled FL) in the synoptic context.

                      Image: fig11_6.jpg
                      Legend: At 1200 UTC the frontal line FL merged with the stationary
                      convective line SCL. It was clearly associated with wind shift and some
                      temperature drop.


                      Image: fig11_7.jpg
                      Legend: At 1300 UTC the frontal line FL tilted and moved eastward. It was the
                      beginning of the end of heavy rainfall in Vaison. A remarkable
                      mesoscale high (1015 hPa) formed on its northern end. This was likely to
                      have been caused by a combination of the large-scale cold air advection
                      and an accumulation of cold downdrafts which reinforced the existing cold
                      pool, where the potential temperature dropped down to 15°C on the west side
                      of this meso high. This meso high closely resembles the type of meso high
                      event for flash floods as described in the literature (Maddox et al. (1979)).



              Activity : Sketch of the precipitating systems. Anim2

                      image : fig10_1.gif
                      legend : At 0700 UTC 22 September the convective line which later became
                      the squall line SL was already developed in the Gulf of Lyon, and the northern
                      convective system QL was almost stationary over the foothills of the Massif
                      Central.

                      This visible Meteosat image is interesting because the oblique early morning
                      sunlight highlighted very clear active overshooting tops (note some circular
                      wave features in the rapidly expanding anvil area, may be caused by gravity
                      waves; it is rare for such features to be observed with the Meteosat visible
                      image resolution). These were organized in a line crossing the centre of the
                      near circular SL cloud shield. So, at this time, the visible image confirmed the
                      active convective line nature of the SL system, which was not obvious on the
                      IR image where the cloud shapes were almost circular.

                      image : fig10_2.gif
                      legend : At 0730 UTC the almost stationary QL system is sketched on the
                      radar composite image and the north eastward propagating squall line SL
                      system.

                      image : fig10_3.gif
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                     legend : At 1015 UTC new convective systems were developing at the rear of
                     the dissipating SL system. The northern system was propagating northward
                     very fast; it was labelled SC because it had some similarities with a supercell.

                     The southern system was characterized as a regenerative stationary
                     convective line SCL.

                     image : fig10_4.gif
                     legend : At 1115 UTC radar echoes showed convective lines were
                     approaching from the west. They were attributed to a frontalline FL.

                     image : fig10_5.gif
                     legend : At 1215 UTC convective lines associated with the SCL and FL
                     systems have merged in only one very active north-south oriented frontal
                     convective line FL.

              Activity : Mesoscale cloud patterns morning– anim3.xml (animator with quiz)

                     Comment : Ten colour enhanced infrared Meteosat images are displayed
                     over France. Each colour corresponds to a black body equivalent temperature
                     interval, calculated after an image calibration. Images are taken during the
                     morning of 22 September; they are spaced every 30 min. The numbers in the
                     second box at the bottom indicate the day number in the month and the UTC
                     time.
                     General question : How could you characterize the behaviour of the southern
                     main convective system, in comparison with that of the northern one?
                     Answer1 : It was quasi-stationary.
                     Feedback1: No. It was not stationary and its appearance was also evolving.
                     Answer2: It was moving fast north-eastward
                     Feedback2: Yes, you are right. Its fast movement was remarkable before it
                     overtook the northern system and merged with it.
                     Answer3: It was a quasi-circular system.
                     Feedback3: It was circular at the beginning but did not maintain this pattern.

                     Images : clps11, 12, …,19, 110,.gif
                     Question to image 9 : On this image is there some characteristic indication of
                     a new convective system development?
                     Answer1 : No. The mesoscale convective system was in its dissipation stage.
                     Feedback1: You are wrong. The mesoscale convective system was
                     effectively in its dissipation stage but there was clear indication of a new
                     convective system development.
                     Answer2: Yes. There are clear indications of a new convective system
                     development on the back of the dissipating mesoscale convective
                     system.
                     Feedback2: Yes, you are right. The development of this new convective
                     system at the south western side of the dissipating mesoscale convective
                     system was quite explosive. It rapidly created very cold cloud tops and
                     initiated a new active mesoscale convective system. Look at the animation
                     between images 7 and 9 (1000 UTC to 1100 UTC).


              Activity : Mesoscale cloud patterns afternoon– Anim4.xml (animator with quiz)

                     Comment : Ten colour-enhanced infrared Meteosat images are displayed
                     over France. Each colour corresponds to a black body equivalent temperature
                     interval, calculated after an image calibration. Images are taken during
                     theafternoon of 22 September; they are spaced every 30 min except when
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                     some data were missing. The numbers in the second box at the bottom
                     indicate the day number in the month and the UTC time.

                     By playing the loop, examine the evolution of the main mesoscale convective
                     system.

                     General question: How could you characterize the behaviour of this
                     mesoscale convective system ?
                     Answer1: It was a big and active mesoscale convective system, almost quasi-
                     stationary and regenerative.
                     Feedback1: Yes, you are right. The size of the system was large. Cold cloud
                     tops and the often observed V-shaped pattern were indications of its strong
                     activity. Its quasi-stationary nature and its regenerative behavior appeared
                     clearly on the animation.
                     Answer2: It was almost circular, similar to an MCC (Mesoscale Convective
                     Complex).
                     Feedback2: No. If you take in to account the cloud top temperatures being
                     less than -30°C (in yellow, white and pink) the shape of the system is
                     elongated and not circular.
                     Images : clps21, 22, …,29, 210,.gif



              Activity : Mesoscale precipitating systems 22 September morning. Anim5.xml
              (animator with quiz)

                     Text: Even if Meteosat images are very useful for monitoring convective
                     clouds they cannot derive accurately enough their rainfall activity. Radar
                     imagery is a useful complementary tool for describing the structures of the
                     precipitating systems. Here we will use radar images superimposed on
                     infrared satellite images for this purpose.

                     Comment : Ten coloured composite radar images are superimposed on black
                     and white infrared Meteosat satellite images over the south eastern part of
                     France. Pink areas correspond to ground clutters near the area of interest or
                     areas out of the view of the radars. Some other fixed ground clutters, due to
                     the Alps, are also in white. Crosses and a squared box are respective
                     locations of surface observation stations and the flood area. Images are taken
                     during the morning of the 22 September at the same hours as on the morning
                     animation of the mesoscale cloud patterns; they are spaced every 30 min. The
                     numbers in the second box at the bottom indicate the day number in the
                     month and the UTC time.

                     By playing the loop examine the evolution of the precipitation patterns
                     associated with the cloud systems.



                     General question:
                     Now you have information on the evolution of the precipitation patterns, which
                     is the type of the main southern convective system, observed during this
                     animation ?

                     answer1: An unorganised multicell thunderstorm.
                     feedback1: No. This system was organised in line.

                     answer2: A classical multicell convective line.
MSG-CAL
Module development
RDS (Rapid Developing Systems)

                     feedback2: It was a convective line, but the fast moving intense precipitation
                     band may have suggested a propagation mode characteristic of a specific
                     type of convective line.

                     answer3: A squall line.
                     feedback3: Yes, you are right. The fast moving intense precipitation band
                     suggested a propagation mode characteristic of a squall line.
                     To confirm this squall line nature, look at the surface parameters.


                     Images: af10s11.gif to af10s110.gif

                     Question to image9 : You see here an intensification of rainfall (in red and
                     yellow), especially near the flood area. By visualizing step-by-step images 6 to
                     9, try to determine from where the intense echoes near Vaison came from.
                     Were they associated with the new convective system development observed
                     at the same time on the satellite images, on the back of a dissipating
                     mesoscale system ?

                     answer1: No. They were part of the squall line.
                     feedback1: You are wrong. They developed clearly behind the squall line, as
                     it was dissipating.

                     answer2: Yes. They were associated with the new convective system
                     development observed at the same time on the satellite images,
                     behind the dissipating squall line.
                     feedback2: Yes, you are right. These echoes developed in the same place as
                     the new convective system development observed at the same time on the
                     satellite images. They developed behind the dissipating squall line (look at
                     image number 7 (1000 UTC)). The radar helps to track different convective
                     cells in the developing cloud system, as the images are more detailed.

              Activity : Mesoscale precipitating systems 22 September afternoon. Anim6.xml
              (animator with quiz)

                     Comment: After a break between 1100 UTC and 1230 UTC (due to some
                     missing satellite images) we will continue to animate radar images
                     superimposed on infrared images observed during the afternoon. The period
                     of the break will be studied further using detailed radar data.
                     Ten coloured composite radar images are superimposed on black and white
                     infrared Meteosat satellite images over the south eastern part of France. Pink
                     areas correspond to ground clutters near the area of interest or areas outof
                     view of the radars. Some other fixed ground clutters due to the Alps are also
                     in white. Crosses and a square box show respective locations of surface
                     observation stations and the flood area. Images are taken during afternoon of
                     22 September at the same hours as on the animation of the mesoscale cloud
                     patterns; they are spaced every 30 min, except when some data are missing.
                     The numbers in the second box at the bottom indicate the day number in the
                     month and the UTC time.

                     By playing the loop examine the structure of the precipitating system, which
                     will be further analysed as a frontal line, before it moved away from the flood
                     area.

                     Images: af10s21.gif to af10s210.gif
MSG-CAL
Module development
RDS (Rapid Developing Systems)

                     General question: Observe the relative location of the intense rainfall pattern
                     with regard to the cloud canopy. Where was it located? Could you deduce
                     some indications concerning the medium and high level winds?

                     Answer1: The intense rainfall band was located just at the southern end of
                     the cloud canopy, at the eastern leading edge of its V-shaped pattern. Medium
                     and high level winds seemed to be southerly, with a much stronger intensity at
                     high levels.

                     Feedback1: Yes, you are right. Intense rainfall under the point of an
                     enhanced V-shaped cloud pattern is a characteristic feature. In this case the V
                     pointed towards the incoming southerly flow at middle and high levels which
                     seemed much more intense at high levels and pushed the high level canopy
                     northward.

                     Answer2: It was located out of the clouds, I do not understand why.

                     Feedback2: A small part of the rainfall band seemed to be out of the clouds at
                     its southern end. It could have been like this because the cloud top of the
                     newly generated cells are not big and cold enough to be well observed.
                     Remember also that the observation time of the Meteosat radiometer at this
                     location was about 10 min in advance of the radar observation for the same
                     official image time.

                     Answer3: Swinging in the rain cloud canopy.
                     Feedback 3: Are you sleeping ?.. please, wake up !


              Activity : Summary of the convective systems evolution. Summary.xml
                      Text : - From early in the morning, the Mediterranean coast was influenced at
                      low levels by a south-easterly advection of warm and moist air.

                     - A squall line (SL) generated in the Gulf of Lyon crossed over the flood area
                     around 0845 UTC.
                     - It generated at its rear a cold pool at low levels.

                     - Around 0930 UTC a fast northward moving convective cell SC was initiated
                     just south to the Alpilles. This had some similarities with a supercell.

                     - It was followed after 1000 UTC by a stationary convective line (SCL)
                     (sketched here at 1045 UTC). This was composed of cells initiated just south
                     of the Alpilles. They grew more vigorous as they moved north-eastward over
                     the cold pool and the cold pool was reinforced.

                     -    A frontal convective line (FL) was slowly approaching from the west
                          (sketched here at 1130 UTC). It merged with the stationary convective line
                          (SCL) after 1145 UTC. Its eastward progression was slow until 1400 UTC
                          allowing large rain accumulation around Vaison, as it is described below.

                     Animation : vaison.gif
MSG-CAL
Module development
RDS (Rapid Developing Systems)


Unit of Study 3c – Short-track presentation of
the Vaison case study (focussed on Meteosat
images)
Objectives: Observation of an explosive development on satellite images
Prerequisites: Knowledge of the IR and VIS channels of Meteosat first generation



       Environment

               Activity : Large scale cloud patterns – Anim1.xml (animator with quiz)

               Comment: Ten infrared Meteosat images are displayed. They are roughly 3 h
                    spaced except when some data were missing. The numbers in the second
                    box at the bottom indicate the daynumber and the UTC time.

                       By playing the animation try to track the main cloud signatures associated
                       with the synoptic situation: the clouds associated with the center of the cutoff
                       low;
                       - the clouds associated with the cold front drawn on the 1200 UTC 21
                       September surface analysis;
                       - the areas prone to convective developments.

                       General question: How could you characterize the developments of the deep
                       convective systems?
                       Answer 1 : The developments of the deep convective systems were chaotic
                       and mainly driven by the diurnal heating cycle.
                       Feedback 1: No. The development of deep convective systems had some
                       kind of organization in a belt moving eastward. The diurnal heating cycle was
                       not the leading factor, some convective systems developed during the night or
                       the early morning.
                       Answer 2 : The deep convective systems developed in a convective belt
                       preceding the surface cold frontal zone, oriented from south to north and
                       moving eastward. Three different phases could be roughly distinguished
                       during the
                       animation period :
                       -Phase 1 = images 1 to 3 (1530 UTC to 2130 UTC the 21 September)
                       -Phase 2 = images 4 to 6 (0130 UTC to 0530 UTC the 22 September)
                       -Phase 3 = images 7 to 9 (0930 UTC to 1530 UTC the 22 September)
                       Feedback 2: Yes. We can roughly distinguish these 3 phases:§
                       - during phase 1, the convective developments occured relatively far away
                       from the frontal zone over the southern part of France and eastern part of
                       Spain, they seemed to be influenced by the diurnal heating cycle;§
                       - during phase 2, several deep convective systems were activated in the
                       southern part of the belt when it was crossing the Spanish Mediterranean
                       coast and came over the warm sea of the Gulf of Lyon;§
                       - during phase 3, major mesoscale convective systems developed over the
                            south eastern part of France. It was remarkable that they became more
                            active (cold cloud top temperatures) when some cloud elements, perhaps
                            associated with the surface cold front, overtook the convective belt and
                            merged with it."
MSG-CAL
Module development
RDS (Rapid Developing Systems)

                     Images lgscal1 to 10.jpg

                     Particular question to image 1 : Which cloud feature was associated with
                     the cutoff low center on this image? By tracking this feature in the following
                     images what could you deduce about the evolution of this low?
                     Answer1: A small coma cloud. The further evolution gave some indication that
                     the low was becoming less organized and filling.
                     Feeback1: Yes, you are right. After growing on the next image the coma cloud
                     has been slit into several small clusters. It was an indication that the low was
                     becoming less organized and filling.
                     Answer 2:. An open cell becoming a squall line. It was an indication that the
                     low was deepening.
                     Feedback 2: No, sorry. This answer does not correspond to the reality. The
                     cloud signature on this image in the center of the low is characteristic of a
                     small coma cloud and not of an open cell.

                     Particular question to image 9: Which characteristic feature could you
                     recognize on the main convective system present on this image?

                     Answer1: A coma-shaped convective cloud.
                     Feeback1: No. This is not the characteristic shape of a coma cloud.
                     Answer 2:. A V-shaped wedge of cloud.
                     Feedback 2: Yes, you are right. This V-shaped wedge is a characteristic
                     shape of some severe or quasistationary convective systems occuring with
                     strong high level winds.
                     Answer 3: Overshooting tops.
                     Feedback 3: There are likely overshooting tops in this deep convective
                     system, but grey scale contrast is not enhanced enough to clearly identify
                     them.




              Activity : Mesoscale cloud patterns morning– anim2.xml (animator with quiz)

                     Comment : Ten colour enhanced infrared Meteosat images are displayed
                     over France. Each colour corresponds to a black body equivalent temperature
                     interval, calculated after an image calibration. Images are taken during the
                     morning of 22 September; they are spaced every 30 min. The numbers in the
                     second box at the bottom indicate the day number in the month and the UTC
                     time.
                     General question : How could you characterize the behaviour of the southern
                     main convective system, in comparison with that of the northern one?
                     Answer1 : It was quasi-stationary.
                     Feedback1: No. It was not stationary and its appearance was also evolving.
                     Answer2: It was moving fast north-eastward
                     Feedback2: Yes, you are right. Its fast movement was remarkable before it
                     overtook the northern system and merged with it.
                     Answer3: It was a quasi-circular system.
                     Feedback3: It was circular at the beginning but did not maintain this pattern.

                     Images : clps11, 12, …,19, 110,.gif
                     Question to image 9 : On this image is there some characteristic indication of
                     a new convective system development?
                     Answer1 : No. The mesoscale convective system was in its dissipation stage.
MSG-CAL
Module development
RDS (Rapid Developing Systems)

                     Feedback1: You are wrong. The mesoscale convective system was
                     effectively in its dissipation stage but there was clear indication of a new
                     convective system development.
                     Answer2: Yes. There are clear indications of a new convective system
                     development on the back of the dissipating mesoscale convective
                     system.
                     Feedback2: Yes, you are right. The development of this new convective
                     system at the south western side of the dissipating mesoscale convective
                     system was quite explosive. It rapidly created very cold cloud tops and
                     initiated a new active mesoscale convective system. Look at the animation
                     between images 7 and 9 (1000 UTC to 1100 UTC).


              Interaction : Mesoscale cloud patterns afternoon– Anim3.xml (animator with
              quiz)

                     Comment : Ten colour-enhanced infrared Meteosat images are displayed
                     over France. Each colour corresponds to a black body equivalent temperature
                     interval,
                     calculated after an image calibration. Images are taken during theafternoon of
                     22 September; they are spaced every 30 min except when some data were
                     missing. The numbers in the second box at the bottom indicate the day
                     number in the month
                     and the UTC time.

                     By playing the loop, examine the evolution of the main mesoscale convective
                     system.

                     General question: How could you characterize the behaviour of this
                     mesoscale convective system ?
                     Answer1: It was a big and active mesoscale convective system, almost quasi-
                     stationary and regenerative.
                     Feedback1: Yes, you are right. The size of the system was large. Cold cloud
                     tops and the often observed V-shaped pattern were indications of its strong
                     activity. Its quasi-stationary nature and its regenerative behavior appeared
                     clearly on the animation.
                     Answer2: It was almost circular, similar to an MCC (Mesoscale Convective
                     Complex).
                     Feedback2: No. If you take in to account the cloud top temperatures being
                     less than -30°C (in yellow, white and pink) the shape of the system is
                     elongated and not circular.
                     Images : clps21, 22, …,29, 210,.gif




Unit 4 – General presentation of new MSG
features, channels and products
Environment

Learning objects :
SAF product reference sheets
      MSG-CAL
      Module development
      RDS (Rapid Developing Systems)

      Gordon’s “safprods.ppt” presentation



             Activity 1: Knowledge object
             1 - Multichoice quiz with feedback.

Question 1     How is MSG stabilised in space?
Option 1       3 axis stabilisation
Feedback 1     No. It has been decided to build on the well-proved
               technique of the previous Meteosat
Option 2       Rotation
Feedback 2     Yes

Question 1-bis What is the name of the main payload on MSG
Option 1       SEVERE STORM
Feedback 1     No. The name is an acronyme for Spinning Enhanced
               Visible and Infrared Imager
Option 2       SEVIRI
Feedback 2     Yes


Question 2     What is the nominal image repeat cycle of MSG?

Option 1       1 hour
Feedback 1     Wrong. MSG improves on all characteristics of the previous
               Météosat, including the image repeat cycle
Option 2       15‟
Feedback 2     Correct
Option 3       10‟
                                                                       st
Feedback 3     No. MSG improves the image repeat cycle of Météosat 1
               Generation, but not that much in nominal mode.
               Nevertheless, shorter repeat cycles are programmable if an
               image of a reduced area of Earth is required


Question 3     Does the value of the image repeat cycle mean that MSG
               rotates twice faster than Meteosat
Option 1       Yes
Feedback 1     Wrong. Both satellites rotate at the same speed, 100 rpm
Option 2       No, it means that less lines are scanned
Feedback 2     No, remember that MSG has better performances than
               Meteosat
Option 3       No, it means that more lines are scanned at the same time
Feedback 3     Right. Several detectors are used to scan several lines at
               the same time



Question 4     How many channels are provided by MSG?
Option 1       4
Feedback 1     More. MSG has so-called „cold‟ channels and „warm‟ or
               „solar‟ channels
Option 2       8
Feedback 2     This is the number of „cold‟ (Infra-red channels). But the
      MSG-CAL
      Module development
      RDS (Rapid Developing Systems)

                solar channels are missing.
Option 3        12
Feedback 3      Yes. These channels are known as either 'cold' channels
                (IR3.9, IR6.2, IR7.3, IR8.7, IR9.7, IR10.8, IR12.0, IR13.4) or
                'warm' or 'solar' channels (HRV, VIS0.6, VIS0.8, NIR1.6.)


Question 5      What is the sampling distance (size of the pixel) at sub-
                satellite point for the channels?
Option 1        3 km
Feedback 1      Quite right. All the channels except High Resolution Visible
                – HRV – have this resolution.
Option 2        1 km
Feedback 2      No. Only the High Resolution Visible channel has this
                resolution.
Option 3        It depends on the channel
Feedback 3      Right. All the channels have a 3 km sampling distance,
                except the High Resolution Visible – HRV – which has a
                sampling distance of 1 km.

  Question 6          Have all channels the same earth coverage?
  Option 1            Yes
  Feedback 1          Wrong
  Option 2            No
  Feedback 2          You are right. (image)
                               All Channels except HRV                    HRV (nominal and
                      alternative coverage)


Question 7      What mean the denominations image 1.0 and image 1.5
Option 1        Two different releases of the Eumetsat image processing
                software
Feedback 1      No, this is not related with software version
Option 2        Two different levels of image processing
Feedback 2      Yes. The Level 1.0 data correspond to the image data as
                acquired by the MSG satellite before any ground processing
                has taken place.
                Level 1.5 data is corrected in real-time for all radiometric
                and geometric effects and geolocated using a standardised
                projection and is therefore suitable for the derivation of
                meteorological products and other further meteorological
                processing.
Option 3        Two different sizes of images.
Feedback 3      No.



      Activity 2: knowledge object
      A number of SAF (Satellite Application Facilities) are to produce products derived from the MSG
      image data. A selection of products are presented here. Please drag and drop the descriptions at the
      right place.
      Once the correct answer is given, pop-up with the SAF reference sheet.

      CRR: Convective Rainfall Rate                             Information on rainfall intensity
   MSG-CAL
   Module development
   RDS (Rapid Developing Systems)

    HRW: High Resolution Winds                                 Winds at high resolution

    LPW: Layer Precipitable Water                              Information on the atmospheric water vapour
                                                               contained in a vertical column of unit cross-
                                                               sectional area, in two or more layers in the
                                                               troposphere
    RDT: Rapid Developing Storms                               Information about significant convective
                                                               systems
    SAI: Stability Analysis Imagery                            Information on the stability of the troposphere

    TPW: Total Precipitable Water                              Amount of liquid water, in millimeters, if all the
                                                               atmospheric water vapor in the column were
                                                               condensed

    CM: Cloud Mask                                             Information on the presence of clouds within
                                                               each pixel

    CTTH: Cloud Top Temperature and Height                     Information on the cloud top temperature and
                                                               height for all pixels identified as cloudy in the
                                                               satellite scene

    CT: Cloud Type                                             Information on the major cloud classes

    PC: Precipitating Clouds                                   Numerical value for the likelihood of
                                                               precipitation within the following four
                                                               precipitation intensity classes

    AMA: Air Mass Analysis                                     Evaluation of basic quantities describing air-
                                                               masses

    ASII: Automatic Satellite Image Interpretation             Automatic diagnosis of satellite features in
                                                               terms of conceptual models



   Unit 5a – Which new MSG channels can help
   for the short range forecasting of a RDS

   Subject
   On the synoptic point of view, in this case of rapid developing systems, create a list of satellite
   channels which could help to improve the short term forecasting.
   See case studies (GOES other channels) to illustrate the advantages.

   Activities

1. Drag and drop exercise : MSG channels (KO channels.xml)

   Put the MSG channels at the right place on the wavelength scale
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)




       2. Quiz : which channels can be used for the forecasting of RDS (KO rdschan.xml)

       Rajouter articles de Karcher en environnement si possible version électronique : problème
       format demandé à Peter

       The learner will be guided by quizzes and feedback to browse this information and decide if RDS
       could be better forecast or detected with new channels.

       Once the learners has given the correct answer, a short case study (when available) will illustrate it.

       A link will be provided from each channel to quick information (pop-up)



Channels        Ver less Feedback for yes             Feedback for no                       Case study
                 y   or                                                                     (Access to the
                usef not                                                                    case study, or
                 ul usef                                                                    illustration, is
                      ul                                                                    allowed after
                                                                                            a good
                                                                                            answer)
0.6 and 0.8       x          You are right.           No. Visible data are the historical   5a1
                             Visible information is   basis of satellite meteorology.
Quick Info:                  essential to early       They are the most natural way of
Detection of                 detect rapid             detecting and following cloud
clouds and                   developments. The        developments. These channels
structures,                  information about        allow to follow only existing
follow-up of                 storm cloud              developments, but are precious for
clouds,                      top morphology is        nowcasting and short range
aerosol                      available due to         forecasting.
observation,                 shadows cast by
follow-up of                 cloud tops at
vegetation                   surrounding cloud
                             layers.
                             See the example of
                             the GOES case
                             study
1,6                     x    Your are not wrong       Yes, this channel is only used in
                             in the sense that the    applications like determination of
Quick info                   major advantage of       cloud type of creation of a cloud
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)

Differentiation           the 1.6 microns         mask, though some studies on the
between                   channel is its          convective storm cloud tops are in
snow and                  superior ability to     progress. But can you identify
clouds, water             separate ice and        which is the 1.6 channel in the
clouds and                water clouds            following set of images?
ice clouds                because of the
information on            stronger absorption
aerosols.                 of ice than water at
                          this wavelength.
                          This information can
                          therefore be used to
                          monitor the
                          development of
                          convective clouds,
                          but this is at the
                          research stage.

3.9               x       You are an expert!      You are almost right! Indeed the     5a3
Quick info                At the temperature      main use of this channel helps to
Mixture of                of convective storm     detect low clouds and fog, or
emitted and               cloud tops, the         surface temperatures during night.
reflected                 information of this     Nevertheless, studies show that
radiation.                channel is mainly       interesting features of the storm
Detection of              reflected solar         cloud tops can be detected in this
low clouds                radiation. Hence,       channel.
and fog. Sea              the reflected
or land                   component plays a
temperature               major role in
during night.             appearance of
                          convective storms in
                          these channels in
                          daytime hours.
                          Some of the storms
                          exhibit a significant
                          increase of cloud
                          top 3.7 micron
                          reflectivity and
                          research is made
                          about the link
                          between these
                          features and the
                          internal structure
                          and intensity of the
                          storm.
                          See the 26 april
                          1994 case study to
                          learn more about
                          these features.
6.2 and 7.3       x       You are right.          Are you sure? Do you think that       5a4
Quick info                The knowledge of        the derivation of humidities from
Water vapor               the dynamic of the      the higher and lower upper
of the medium             upper troposphere is    troposphere cannot help to
and high                  essential to forecast   forecast the instability and thus the
troposphere,              RDS. On the other       possibility of strong developments?
follow-up of              hand, the two “water
the clouds,               vapor” channels         L'un des deux a des propriétés
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)

height of                 allow to derive the      similaires à celui de Météosat alors
semi-                     humidity from two        que l'autre se rapproche
transparency              different layers of      des caractéristiques du canal
clouds                    the troposphere.         utilisé sur les satellites américains
                          This data will help a    GOES ; il correspond à une
                          lot to assess the        fonction de poids qui a son
                          stability criteria of    maximum un peu plus bas que le
                          the atmosphere, and      maximum de pour
                          forecast possible        Météosat, qui se situe entre 500 et
                          severe storm             300 hPa. Actuellement pour
                          developments. The        couvrir nos besoins sur l'Atlantique
                          major improvement        Nord nous fabriquons une
                          compared with            composite GOES + Météosat. Bien
                          Meteosat is the          sûr on
                          splitting of the         observe une discontinuité séparant
                          information.             les deux zones mais pour les
                                                   prévisionnistes l'utilisent à peu
                          Have a look at the       près de la même manière.
                          possibilities of using
                          water vapor info to      Je pense que l'on pourra
                          analyse upper            réellement voir comment utiliser
                          troposphere              intelligemment cette double
                          dynamics and hence       information quand les images
                          the probability of       seront sur les écrans des stations
                          RDS.                     de travail et que les
                                                   prévisionnistes croiseront ces
                                                   données avec les champs de
                                                   modèles.
8.7                   x
Quick info:
Quantitative
information on
this cirrus,
differentiation
of water and
ice clouds
9.7               x       You are an expert!       This is a difficult question, but we 5a5
                          This channel, which      are afraid you are wrong. The
Quick info                does not exist on        ozone channel conveys
(ozone                    GOES, allows to          information on the low layer of the
channel)                  measure the              troposphere (tropospheric ozone)
The                       integrated ozone         and on the “ozone layer” in the low
brightness                and therefore            troposphere. Once the first part of
temperature               follow-up the            the information has been filtered,
observed in               dynamic                  the second part allow to follow the
the SEVIRI                tropopause,              dynamic of the low stratosphere
9.7 m                     important parameter      and of the tropopause, which is of
channel is                to forecast explosive    great interest for the forecast of
composed of               development.             explosive developments.
the emission
of                        These total ozone
the cold                  observations are
stratospheric             likely to convey a
ozone, and of             wealth of
the emission              information about
of the warm               dynamical
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)

surface                   processes in the
attenuated by             lower stratosphere,
the ozone                 which will be used
layer.                    by the forecasters,
                                               st
Both these                like the Meteosat 1
components -              Generation Water
called                    vapor channel, but
respectively              this image will
foreground                describe a higher
and                       layer (low
background                troposphere, about
contributions -           400 to 40 hPa ).
have the                  This case study will
same order of             give you more
magnitude.                information about
                          the use of this
                          channel
10.8              x       Right. As for             I am afraid, you are wrong. The     5a6
and 12.0                  Meteosat, the IR          infrared channels give important
                          channels allow to         information on the cloud top
Quick info:               monitor the cloud         temperature, and then the
Temperature               top temperature           evolution of rapid developing
of land and               (hence the height of      storms. For instance, the thermal
clouds,                   the clouds). On           pair structure, described as "cold-
detection of              MSG, the sensivity        U" and "embedded warm spot" is a
cirrus and                of the IR 12 channel      clear marker of strong convective
retrieval of              to low-level moisture     storms.
precipitable              allows it to be
water                     combined with the
                          10.8 micron channel
                          to create derived
                          products related to
                          surface temperature
                          (hence instability)
                          and precipitable
                          water, all important
                          parameters to
                          forecast storms.
                          An example is given
                          on the following
                          case study.
13.4              x       You are right. The        Equivalent GOES 8 sounder band     5a7
Quick Info                information on the        5
(CO2                      low troposphere
channel)                  temperature
Improvement               contributes to
of the                    instability indexes,
analysis of               therefore to
the cirrus                forecasting of
transmission              convective
factor.                   developement.
Information               Are you able to
on the                    select the 13,4
temperature               channel in this small
of the low                quiz?
troposphere
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)

in cloud free
pixels for the
evaluation of
instability

       Activity 5a1.xml animation + hotspot


       Example of visible channel. GOES 29 may 2001

       Resources : 29mv1 to 29mv63.gif
       Credits : Authors: Dan Bikos and John Weaver, Cooperative Institute for Research in the
       Atmosphere (CIRA) Colorado State University Fort Collins, Colorado

       The visible loop shows explosive convective developments.
       Geographical references are not mentioned as they are not interesting for our purposes.

       General description of the situation

       GOES Rapid Scan Operations (RSO) were automatically scheduled because of an approaching
       upper low. At lower-levels, a moist, unstable air mass was in place and a dryline was moving
       eastward. Mid/low-level clouds could be seen in the unstable air to the east of the dryline. A large,
       mesoscale convective system (MCS) was moving east leaving behind a north-south oriented Low-
       Level Thunderstorm outflow (LTO) boundary. Elevated convection dissipated and left behind a circle of
       clearing (18:15 - 1845 UTC shows the circle most readily). It is unclear what role this outflow played in
       later convection.
       The first thunderstorms in Texas developed along the dryline in the southwest panhandle and shortly
       thereafter northwest of Amarillo. The storms continued to develop and intensify, but did not produce
       significant tornadoes until the storm that originated northwest of Amarillo interacted with the outflow
       boundary shown in figure.

       Another example (without comments)
         Nesscity.avi

       Rapid identification of MCS splitting
         radsat1.avi


       Activity 5a3.xml
       Case study for channel 3.9
       26 April 1994 as studied by M. SETVAK, RABIN, LEVIZZANI et DOSWELL.
       Identify source of plume.


       Activity 5a4.xml
       Case study and theory for 6.2 and 7.3 channels

       On 29 May 2001 Rapid Scan Operations (RSO) were automatically scheduled based on an
       approaching upper low moving towards the Plains from north central New Mexico. This low could be
       followed as it moved eastward in the water vapor (6.7 µm) imagery (see animation). The water vapor
       imagery also showed evidence
        of an elongated jet streak extending from southwestern New Mexico into the Oklahoma panhandle.
       At lower-levels, a moist, unstable air mass was in place across most of west Texas and a dryline was
       moving eastward.
       A large, mesoscale convective system (MCS) was moving east across Oklahoma leaving behind a
       north-south oriented Low-Level Thunderstorm outflow (LTO) boundary in the central Texas panhandle.
MSG-CAL
Module development
RDS (Rapid Developing Systems)

Elevated convection over the central Texas panhandle dissipated and left behind a circle of clearing
(18:15 - 1845 UTC
 shows the circle most readily). It is unclear what role this outflow played in later convection.

Interaction : Animation
Resources : GOES 29 may 2001 fig.1

The water vapour imagery for the observation of the dynamics. (Anasyg Presyg, the dynamic
tropopause).

Activity 5a5.xml

Case study of channel 9.7

will be based on Fernand Karcher’s QJRMS article.

Attendre réponse Peter pour savoir si les images illustratives sont inclues.

Mesoscale cold pool (article de Vaugham)
Mail envoyé à G.Vaughan
copyright + cartes d’origine

étude de cas avec hot spots sur les cartes.

Activity 5a6.xml
Example of 10.7 IR channel GOES 29 may 2001
On 29 May 2001, the Rapid Scan Operations (RSO) were automatically scheduled based on an
approaching upper low moving towards the Plains from north central New Mexico. A large, mesoscale
convective
 system (MCS) was moving east across Oklahoma leaving behind a north-south oriented Low-Level
Thunderstorm outflow (LTO) boundary in the central Texas panhandle. Elevated convection over the
central Texas panhandle dissipated and left behind a circle of clearing (18:15 - 1845 UTC shows the
circle most readily). It is unclear what role this outflow played in later convection.

The first thunderstorms in Texas developed along the dryline in the southwest panhandle and shortly
thereafter northwest of Amarillo. The storms continued to develop and intensify, but did not produce
significant tornadoes until the storm that originated northwest of Amarillo interacted with the outflow
boundary. A large tornado was observed by several storm chasers near White Deer. Another storm
south of the White Deer storm also crossed the boundary but did not produce a tornado. The
interaction of the storm with this boundary and the role of the other boundaries is unclear at this time.

The following animation shows the 10.7 µm imagery for the period 16:55 - 00:45 local daylight time. It
shows the deep convection in the Texas panhandle, and the circulation associated with the upper low
moving east. It is interesting to note that the largest storm in the Texas panhandle -- the one with the
coldest cloud tops on the southern end of the line did not produce a significant tornado.


Resources : 29mv1 to 29mv63.gif
Credits : Authors: Dan Bikos and John Weaver, Cooperative Institute for Research in the
Atmosphere (CIRA) Colorado State University Fort Collins, Colorado


Activity 5a7.xml
Example for channel 13.4
This channel will be quantitatively used in products.
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)

       Here, quiz between different images to select the good one.




       Unit 5b – Which SAF or MPEF products can
       help for the short range forecasting of a RDS
       Subject
       On the synoptic point of view, in this case of rapid developing systems, create a list of products which
       could help to improve the short term forecasting.
       See case studies to illustrate the advantages.

       Activity (usefprod.xlm)

       With the product reference sheets available, decide if the product is very useful, less useful or useless
       for the nowcasting or short range forecasting of RDS.

       Once the learner has given the correct answer, a short case study (when available) will illustrate it.



MPEF / SAF       Very    Quite    Usele Feedback for         feedback for      Feedback for useless              Case study/
products        useful   useful    ss   very useful          quite useful                                        example
Total Ozone                x            It is not wrong.     We agree.         We disagree. Even if this product 5b.1 (=5a5)
                                        The total ozone      The               does not focus only on RDS
                                        imagery gives        evolution of      forecasting, it gives important
                                        the forecaster a     dynamic           clues on the tropopause
                                        good overview        meteorology       dynamics, and then on the
                                        of the low           in the last       evolution of storms at short and
                                        stratosphere         years show        medium term.
                                        dynamics.            that the
                                        Nevertheless,        tropopause
                                        this is maybe        or low
                                        more a tool for      stratosphere
                                        forecasting          dynamics
                                        than                 plays a
                                        nowcasting           major role in
                                                             the
                                                             developmen
                                                             t of
                                                             explosive
                                                             phenomena
                                                             or violent
                                                             storms.
Convective        x                       Yes. The main      Quite right,      The CRR product is an image          5b2
Rainfall Rate                             use of this        but we            product providing information
(CRR)                                     nowcasting         would say         on rainfall intensity in mm/hour,
                                          product is for     that it is very   for 5 or 6 pre-defined
                                          the                useful. CRR,      intensity classes, and for clouds
                                          monitoring of      providing         identified as convective cells. Do
                                          convective         quantitative      you think it is really useless for
                                          systems, i.e.      information,      RDS nowcasting?
        MSG-CAL
        Module development
        RDS (Rapid Developing Systems)

                                         their rain        will be
                                         intensity.        complement
                                                           ary to the
                                         The short         Rapidly
                                         repeat cycle is   Developing
                                         an essential      Thunderstor
                                         feature           ms
                                         providing         product,
                                         information on    which will
                                         changes of        give more
                                         convective        qualitative
                                         systems from      information
                                         one               on the
                                         cycle to the      developmen
                                         next.             t of
                                                           convective
                                                           systems.

High                             x       Not quite.        Not really.     Yes. This product is meant as
Resolution                                                 Other           input into numeric models. When
Wind Vectors                                               observation     monitoring severe systems on
(HRW)                                                      al data will    land, the forecasters will have
                                                           be used for     observations for the follow-up of
                                                           monitoring      violent winds.
                                                           RDS.
Layer                    x                You are maybe We believe         This product provides, in the       5b3
Precipitable                             right, although you are           absence of clouds, information
Water (LPW)                              we believe that right. The        on
                                         this product will information     the atmospheric water vapour
                                         help for          on the          contained in a vertical column of
                                         forecasting (24 vertical (two     unit cross-sectional area, in two
                                         hours or more) layers) and        or more layers in the
                                         and not really    horizontal      troposphere.
                                         for nowcasting distribution       Don‟t you see an application for
                                         of RDS.           of moisture     severe convection forecasting?
                                                           in the          Of special
                                                           atmosphere      interest is the detection of dry-
                                                           is useful for   over-moist configurations and of
                                                           the short       horizontal moisture gradients, as
                                                           term            these are factors contributing to
                                                           forecasting     the formation of severe storms.
                                                           of severe
                                                           convection,
                                                           i.e. the
                                                           monitoring
                                                           of the
                                                           pre-
                                                           convective
                                                           environment
                                                           and the
                                                           determinatio
                                                           n of the
                                                           storm type
                                                           and storm
                                                           intensity.
Rapid             x                      Definitively      We believe      We are afraid you are wrong.        5b4
      MSG-CAL
      Module development
      RDS (Rapid Developing Systems)

Developing                             right. The         that this       This is a typical useful product for
Thunderstorm                           product will       product is      the follow-up of developing
s (RDT)                                provide            amongst the     storm, and it can help to raise
                                       information        most            alarm quickly when such
                                       about              interesting     phenomena are appearing.
                                       significant        for the
                                       convective         nowcasting
                                       systems from a     of RDS.
                                       single storm to
                                       meso-alpha
                                       scale and
                                       therefore give
                                       precious
                                       information for
                                       nowcasting of
                                       such storms.
                                       See our case
                                       study for more
                                       information.

Stability              x               Maybe not          We agree.       No. This is also an interesting      5b.5
Analysis                               alone. Since       This product    monitoring tool, at least for short
Imagery (SAI)                          trigger            clearly will    term forecasting. The SAI
                                       mechanisms         require         product will provide information
                                       are                supporting      on the stability of the troposphere
                                       required to set    information     with the scope to
                                       off severe         describing      delineate unstable and stable
                                       convection,        the vertical    areas. It is a priori clear that the
                                       the product will   state of the    SAI product will not allow to
                                       normally be        atmosphere      monitor
                                       used               (e.g. low       all important features for
                                       together with      level           convection. For instance, the lack
                                       parameters         humidity &      of information in the SEVIRI
                                       derived            temp.)          channels
                                       from NWP or        before it can   on low-level humidity and
                                       from in-situ       be used to      temperature will limit the skill of
                                       observations       predict         the product to detect
                                                          destabilisati   destabilisation
                                                          on of the       caused by increased moisture in
                                                          atmosphere.     the lower layers. It should also be
                                                                          reminded that for the formation
                                                                          of sever convective storms a so
                                                                          called triggering mechanism,
                                                                          which lifts the air and sets the
                                                                          atmosphere in motion is
                                                                          frequently needed
Total                  x               Not bad. The       Yes, we         Are you sure? This product gives, 5b6
Precipitable                           Total              agree. The      amongst other, some information
Water (TPW)                            Precipitable       TPW             on the intensity of the
                                       Water (TPW)        product can     phenomena to be expected (e.g.
                                       product will       be used for     amount of
                                       give information   objective       precipitation) and the location
                                       on the total       and even        where severe convection is likely
                                       atmospheric        quantitative    to occur (e.g. “dry lines”, areas of
                                       water              studies in      strong moisture contrasts).
                                       vapour             the area of
      MSG-CAL
      Module development
      RDS (Rapid Developing Systems)

                                       contained in a   Nowcasting
                                       vertical column  and VSRF.
                                       of unit cross-   It allows the
                                       sectional area   diagnosis
                                       extending from   and
                                       the earth's      nowcasting
                                       surface          of the total
                                       to the top of theavailable
                                       atmosphere.      water
                                       But we believe   vapour
                                       that it is maybe content in
                                       more useful for  pre-
                                       numerical        convective
                                       models,          areas and
                                       although it can  therefore
                                       give indications helps to
                                       for nowcasting.  classify the
                                                        air mass in
                                                        terms of
                                                        severe
                                                        weather air
                                                        masses
Cloud Mask                     x       Not directly.    Maybe you       We agree. The direct observation N/A
(CM)                                   The cloud mask are right,        of the satellite imagery is
                                       is mainly a      although we     certainly better for nowcasting.
                                       basis for other think that
                                       nowcasting       this product
                                       products         is really
                                                        interesting
                                                        for
                                                        nowcasting.
                                                        This is
                                                        rather an
                                                        input for
                                                        other
                                                        products or
                                                        NWP.
Cloud Top       x                      Yes. One         Why not.        No. Think just of the input for
Temperature /                          possible use of This is true     rapidly developing thunderstorms
Height                                 this product is  that the
(CTTH)                                 in the analysis product will
                                       and early        be very
                                       warning of       useful for
                                       thunderstorm     automatic
                                       development      detection
                                                        and for input
                                                        for other
                                                        products.
Cloud Type                     x       Not really. The We believe       Yes, you are right. The CT is an   N/A
(CT)                                   cloud type is an that for        input for other products.
                                       input for other  nowcasting,
                                       product, but is  the direct
                                       not really       analysis by
                                       needed for       human
                                       nowcasting.      being is
                                                        more
       MSG-CAL
       Module development
       RDS (Rapid Developing Systems)

                                                             efficient
Precipitating                   x                                                                                N/A
Clouds (PC)
Air Mass                 x              Your are right:      We agree.        Not really: The main use of the     5b8
Analysis                                The product will     As a             AMA product is to monitor air
(AMA)                                   be used to           automatic        masses for an early recognition
                                        monitor              classification   of unstable
                                        air masses           of risk          weather situations. It can be an
                                        (and                 areas, this      help for the forecaster to identify
                                        boundaries),         product will     quickly the zone with possible
                                        axes                 help the         development of instability clouds.
                                        and ridges of        forecaster to
                                        the different        focus on
                                        input                them for
                                        parameters,          further
                                        and their points     nowcasting
                                        of
                                        intersection - all
                                        critical zones
                                        for the
                                        development of
                                        severe
                                        weather.
                                        But this is
                                        maybe not the
                                        most useful in
                                        emergency
                                        cases, as it will
                                        be use for
                                        automatic
                                        classification of
                                        risk areas.
Automatic                x              Your are quite       We agree         Really? ASII includes detection of 5b9
Satellite                               right. By            with you.        various phenomena, classified
Image                                   automaticalyy        This product     following various conceptual
Interpretation                          detecting MCS:       helps at an      models, amongst them CBs or
(ASII)                                  developing/mat       early stage      MCS. This can be a real help for
                                        ure/decaying,        for detection    automatic pre-alarm for
                                        this product         of areas         forecasters.
                                        draw the             which can
                                        attention of         be
                                        forecasters on       concerned
                                        specific areas.      by RDS.
                                        Nevertheless,
                                        this is only at
                                        detection stage,
                                        and other
                                        products (RDS
                                        for instance)
                                        will be more
                                        appropriate for
                                        nowcasting


       5b2.XML=5a5.xml
MSG-CAL
Module development
RDS (Rapid Developing Systems)

Existe déjà, à remettre dans l'UoS 5b

5b2.xml
Exemple CRR

5b3.xml
LPW example

5b4.xml
Applet and examples RDT from Météo-France

5b5.xml
SAI examples

5b6.xml
TPW examples
Provided by Pilar Fernández, TPW's principal developer, email: pif@inm.es

5B7.xml
CTTH example

5b8.xml
Example of AMA - 21. March 2002, 06 UTC

Resources : amasymbol.htm demoama.gif exama.html

Credits : ZAMG

Activity : with the help of the legend, click on the areas of unstable air masses


Case 5b.9
Example of ASII analysis - 13 march 2002 case
Activity : with the help of the legend, click on the zones were RDS phenomena are likely to occur.

Resources : demosat.gif + demonwp.gif + asiisym.gif + texts of exasii.html

Credits : ZAMG




Unit 6 – Which MSG features could have helped
for the nowcasting of the Vaison event
Screen equivalent: 1
Learner duration : 10‟


Identification of phenomena that appear between two Meteosat slots. Examples of similar cases with
better frequency or better resolution.
MSG-CAL
Module development
RDS (Rapid Developing Systems)
                                                  st
Activity : explosive developments with Meteosat 1 Generation– Anim1.xml (animator with quiz)


Each IR image will be accompanied by a question helping the learner to identify important features (for
example the explosive development appearing south of the main phenomenon). Attention will be
drawn on the advantages to have more slots and better definition.
Resources:
Images infrarouges de vaison la romaine

Activity : explosive developments – Anim2.xml

Examples of case studies with better resolution and/or scan frequency. Simultation of different
frequencies


GOES visible 4 juillet 1995
Rapid scan METEOSAT day 263 VIS
Rapid scan METEOSAT 02082000

Conclusion : advantages of scan and resolution enhancement




Unit 7 – General overview of MSG products and
features in the scope of RDS forecasting
Screen equivalent: 1
Learner duration : 5‟

Subject: Reinforce the new acquired knowledge

activity :

   MCQ several answers with feedback (retrouver le template)


Questions, answers and feedback will be completed depending of the information presented in the
case studies.

1 -The selection of MSG channels at the design stage of the mission was based on:

a/ The scientists tried to design new remote sensing applications

b/ The channels were to a large extent selected in order that current applications known from the polar
orbiters (NOAA) could easily be run for similar channels on a geostationary satellite. Quite a number of
channels are similar on the NOAA AVHRR imager channels.

2 -There are two WV channels on MSG:

a/ To ensure redundancy in case of failure
MSG-CAL
Module development
RDS (Rapid Developing Systems)

b/ To allow for derivation of humidities from the higher and lower upper troposphere (instead of the
whole upper troposphere).


3 - The 8.7 channel was added

a/ to allow for better cloud type discrimination in the cirrus level (water/ice discrimination)

b/ to retrieve the surface temperature


4 - The ozone channel...

a/ came on board because of the relevance of the stratospheric chemistry
b/ helps to follow low stratosphere dynamics
c/ allow to monitor city ozone pollution


5- The CO2 channel
a/ Is very effective for cloud height determinations, as on previous GOES satellites.
b/ Is used in the SAF product "Total CO2"

6 - Does the ozone channel helps to forecast instability in the low troposphere?

a/ No. The ozone channel has a transmission of about 0.4. The surface and low layers radiance
contributes to the signal in the 9.7 microns channel. In the total ozone algorithm, one gets rid of this
contribution by assuming that the background temperature of the atmosphere under the stratospheric
ozone layer is the same in the 9.7 channel than in the 11 window channel. This approximation is
possible because tropospheric ozone column is 10% of the stratospheric column and because there
are tropospheric absorbers like H2O in the two channels. This background temperature has an RMS
uncertainty of 0.5K. One of the unknown magnitudes is the tropospheric ozone and it would be only
with more information on this column of about 25 dobsons that one could take advantage of the
surface and low layers information

b/Yes, by giving information on the low troposphere temperature

Activity

Matrix MCQ

Select in the following list the very useful channels and products for RDS forecasting. Our answers are
of course subjective, as it can be discussed if a channel or product is very or less useful...

Finir les feedbacks

Vis : yes
1.6 : no
3.9 : yes
WV: yes
8.7 : no
9.7 : yes
IR : yes
13.4 : yes
Total ozone : no
CRR : yes
HRW: no
LPW : no
MSG-CAL
Module development
RDS (Rapid Developing Systems)

RDS : yes
SAI : yes
TPW : no
CM : no
CTTH : yes
CT: no
PV: no
AMA: no




                                                     Reference Information
The following knowledge objects will be added to the general environment

Relevant EuroMET modules
Relevant COMET modules



                    Appendix: description of case studies

References of the case studies

  Case 1     http://www.comet.ucar.edu/resources/cases/c16_04jul95/index.htm obtain data
             http://www.joss.ucar.edu/cgi-bin/codiac/fgr_form/id=33.056
  Case 2     http://www.cira.colostate.edu/RAMM/picoday/010618/010618.html
MSG-CAL
Module development
RDS (Rapid Developing Systems)

								
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