Update on NCAR Auto-Nowcaster

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					Update on NCAR Auto-Nowcaster



Juneau, AK
     The Auto-Nowcaster System


• An expert system which produces short-term (0-1
  hr) forecasts of thunderstorm initiation, growth
  and decay using fuzzy logic.
• Recent developments have allowed human users
  (i.e. forecasters) to input information into the
  system in a relatively quick and simple fashion.
• A test of the updated system in an operational
  environment is taking place at the Dallas/Fort
  Worth WFO.
          The Auto-Nowcaster System
is unique in its ability to provide nowcasts of storm
initiation by…..


                                    Detection and
                                    extrapolation of
                                    surface convergence
                                    boundaries ….

                                    ….that trigger
                                    thunderstorm initiation
                                    and impact storm
                                    evolution.
      Example of Auto-Nowcaster
          Initiation Forecast

1 hour forecast           Verification

          Initiation
          nowcasts




extrapolation
nowcasts
              Flow Chart for the
            Auto-Nowcaster System
                      Forecaster
                        Input
Data Sets
Radar
 WSR-88D
Satellite
Mesonet                                    Predictor Fields
Profiler
                 Analysis Algorithms
Sounding
Numerical
   Model
Lightning


                                       Fuzzy Logic Algorithm
              Final Prediction         - Membership functions
                                       - weights
                                       - Combined likelihood field
              Flow Chart for the
            Auto-Nowcaster System
                      Forecaster
                        Input
Data Sets
Radar
 WSR-88D
Satellite
Mesonet                                    Predictor Fields
Profiler
                 Analysis Algorithms
Sounding
Numerical
   Model
Lightning


                                       Fuzzy Logic Algorithm
              Final Prediction         - Membership functions
                                       - weights
                                       - Combined likelihood field
                   Example of fuzzy logic
                       Predictor Field 1
                                      Membership Function
                                        Yes
Convergence line                .5                          Likelihood



                         Likelihood
                                                                    .5

                                                No
                                0
                                      Lifting Zone
              Predictor Field 2
                           Membership Function

Convergence
                                                 Likelihood                  .1
                                                                        .2
              Likelihood                                      .2
                                                                   .3
                                                    .1


                              Convergence
                         Predictor Field 3
                                   Membership Function
Cumulus clouds
                              1                                  Likelihood
                                     .8                                       -.5
                 Likelihood                 .4
                                                                       .4
                                                           -.5
                                                   -.5

                              -1
                                      Cumulus cloud type
Likelihood 1              Likelihood 2         Likelihood 3




               Weight 1        Weight 2
                                          Weight 3



                               Σ
                                             Final combined
                                             likelihood
                                             of initiation
         Predictor Fields used for
         Combined Likelihood of Initiation

•   Environmental conditions (RUC)
     – Frontal likelihood
     – Layered stability
     – CAPE (max between 900 and 700 mb)
     – Mean 875 to 725 mb Relative
       Humidity
•   Boundary-layer
     – Convergence
     – LI (based on METARS)
     – Vertical velocity along boundary
       (maxW)
     – Boundary-relative steering flow
     – New storm development along
       boundary
•   Clouds
     – Clear or Cumulus                          Blue Regions - Little chance of storm development
                                                 Green Regions - Moderate likelihood
     – Vertical develop as observed by drop in   Red Regions - Areas of forecast initiation
       IR temps
                                                                            60 Minute Initation (rules with satellite data)
                                                      C a pe                                                                                                    Ve rt_ Sum

                                 1                                                                                              1


                              0 .5                                                                                          0 .5
In te r e s t




                                                                                                           In te r e s t
                                 0                                                                                              0
                -5 0 0                0            500              1000    1500   2000                                             0                       5                        10                   15

                             - 0 .5                                                                                        -0 .5
                                                                                                                                                                                            Wt:                 0.10
                                                                                                                                                                                            Range:              0 to 0.10
                               -1
                                                                            Wt:           0.17                               -1
                                                         J K g- 1           Range:        -0.085 to 0.17                                             C o unt o f "uns ta ble " 2 5 m b le ve ls




                               875 - 725 mb Mean Relative Humidity                                                                                           Lifted Index

                    1                                                                                                                                                 1


                 0.5                                                                                                                                                 0.5
                                                                                                                                                                                            Wt:                 0.20
                                                                                                                                                                                            Range:              -0.20 to 0.02




                                                                                                            Interest
Interest




                    0                                                                                                                                                 0
                         0                20          40              60     80    100                                     -5           -4   -3      -2         -1         0    1       2         3   4     5

                -0.5                                                                                                                                             -0.5


                   -1
                                                                            Wt:           0.17                                                                        -1
                                                               %            Range:        -0.17 to 0.17                                                                    oK




                                                Frontal Likelihood                                                                                          Convergence

                    1                                                                                                                                                 1


                 0.5                                                                                                                                                 0.5
                                                                                                            Interest
Interest




                    0                                                                                                                                                 0
                         0                0.2         0.4             0.6    0.8    1                                       -0.1                  -0.05                    0              0.05            0.1

                -0.5                                                                                                                                              -0.5


                   -1
                                                                            Wt:           0.16                                                                        -1
                                                                                                                                                                                            Wt:                 0.08
                                                           Interest         Range:        -0.08 to 0.16                                                              10-3s-1                Range:              -0.02 to 0.08
                                                                                 60 Minute Initation (rules with satellite data) Cont.
                                     Boundary Relative Steering Flow                                                                             Rate Of Change (ROC) IR Temp Rate

                                                              1                                                                                                                                           1


                                                            0.5
                                                                                     Wt:                    0.20                                                                                         0.5
                                                                                     Range:                 -0.2 to 0.2




                                                                                                                          Interest
Interest




                                                              0                                                                                                                                           0
                   -20       -15      -10              -5          0         5      10            15   20                            -10    -9   -8       -7   -6      -5       -4   -3    -2       -1         0

                                                            -0.5                                                                                                                                     -0.5


                                                             -1
                                                                                                                                                                                          Wt: -1                   0.20
                                                              m s-1                                                                                                 Interest              Range:                   0 to 0.20


                                                            M ax W                                                                                                 Sat_Cu

                                              1                                                                                        1


                                           0.5                                                                                        0.5
  Interest




                                                                                                                          Interest
                                              0                                                                                        0
                    -0.5       -0.25               0           0.25          0.5         0.75          1                                    0         1        2            3        4          5              6

                                          -0.5                                                                                       -0.5


                                             -1
                                                                                    Wt:                     0.20                       -1
                                                                                                                                                                                          Wt:                      0.15
                                                              m s-1                 Range:                  0 to 0.20                                                 Interest            Range:                   0 to 0.15


                                           In itia tio n a lo n g B o u n d a r y

                                              1


                                           0 .5
   In te r e s t




                                              0
                    - 0 .5     - 0 .2 5            0            0 .2 5       0 .5        0 .7 5        1

                                          - 0 .5


                                             -1
                                                                                    Wt:                     0.25
                                                             In te r e s t          Range:                  0 to 0.25
          60 Minute Initation (rules with satellite data) Cont.




Boundary Collision:        Sat_Clear:                   Lake:
Wt:      0.12              Wt:       0.40               Wt:       0.10
Range:   0 to 0.12         Range:    -0.40 to 0         Range:    -0.10 to 0




                           Initiation Levels:

                           0.70 => Init 1
                           0.90 => Init 2
                           1.20 => Init 3
Predictor Fields


                     Cumulus
                   development
                   Boundary
                 characteristics
              Satellite Cloud Typing
             B-L characteristics
          Storm motion and trends
       Large-Scale Environment
Predictor Fields


                     Cumulus
                   development
                   Boundary
                 characteristics
              Satellite Cloud Typing
             B-L characteristics
          Storm motion and trends
        Large-Scale Environment
Why do we need a forecaster in the loop??



•   Forecasters see the larger picture
    –   Conceptual Models
    –   Ignore bad data points
    –   Understand limitations of NWP and observations
Forecaster Entered Boundary




                              FAA RCWF
                              Domain
                                June 12, 2003
Draw Tool
Draw Tool
Draw Tool




            Entering a convergence
            boundary in real time
            is as simple as this
            demonstration!
Forecaster-tools:
Boundary Entry
Forecaster Entered Polygons
Where has the Auto-nowcaster been demonstrated ?
      • Weather Forecast Office Washington DC (Sterling, VA)

      • Sydney Australia Forecast Office

      • U. S. Army White Sands Missile Range

      • Central U. S. for the FAA
      Process of being transferred to:
      • Bureau Meteorology Beijing China

      • U.S National Weather Service – Dallas/Fort
      Worth Weather Forecast Office

      • AWIPS
Auto-Nowcaster at Ft. Worth WFO
     Auto-Nowcaster at Ft. Worth WFO
             05 April 2005
On this day, dryline was moving in from the west. Below is an example of one of the Area
Weather Updates that they put out on that day:


AREA WEATHER UPDATE
NATIONAL WEATHER SERVICE FORT WORTH TX
310 PM CDT SUN APR 10 2005 >
WARNING DECISION UPDATE FOR NORTH TEXAS

MESOANALYSIS PROGRAMS SHOW 1000-1500 J/KG CAPE ALONG AND JUST AHEAD
OF DRYLINE. THUS...CU/DEVELOPING STORMS ALONG/E OF DRYLINE SHOULD
CONTINUE TO INTENSIFY. STORM INITIATION TOOL ALSO SUGGESTS HIGH
POSSIBILITY OF DEVELOPMENT FARTHER SW...OVER CORYELL/LAMPASAS COUNTY
AREA. DEEP-LAYER SHEAR MORE THAN SUFFICIENT FOR ORGANIZED STORMS AND
AT LEAST MID-LEVEL MESOS. AS STORMS EVOLVE INTO THE EVENING...A MORE
LINEAR MODE IS EXPECTED.
       Ft. Worth WFO 05 April 2005

Forecast: 2003 Z         Forecast: 2003 Z
Radar Image: 2003 Z      Radar Image: 2108 Z
       Ft. Worth WFO 05 April 2005

Forecast: 2044 Z         Forecast: 2044 Z
Radar Image: 2044 Z      Radar Image: 2142 Z
Ft. Worth WFO 05 April 2005
        Ft. Worth WFO 25 April 2005

• On this day there was a dryline moving in from
  the west.
• Storms developed a couple of hours earlier than
  originally thought.
• The ANC system captured the initiation of this
  event with about a 40-50 minute lead time.
• The storms went severe within 30 minutes of
  initiation (about 50 miles west of DFW Metroplex)
  with quarter sized hail, strong winds and several
  mesocyclones.
       Ft. Worth WFO 25 April 2005

Forecast: 1831 Z         Forecast: 1831 Z
Radar Image: 1831 Z      Radar Image: 1929 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1842 Z         Forecast: 1842 Z
Radar Image: 1842 Z      Radar Image: 1941 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1854 Z         Forecast: 1854 Z
Radar Image: 1854 Z      Radar Image: 1952 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1905 Z         Forecast: 1905 Z
Radar Image: 1905 Z      Radar Image: 2003 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1917 Z         Forecast: 1917 Z
Radar Image: 1917 Z      Radar Image: 2020 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1929 Z         Forecast: 1929 Z
Radar Image: 1934 Z      Radar Image: 2030 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1941 Z         Forecast: 1941 Z
Radar Image: 1940 Z      Radar Image: 2042 Z
       Ft. Worth WFO 25 April 2005

Forecast: 1952 Z         Forecast: 1952 Z
Radar Image: 1951 Z      Radar Image: 2054 Z
       Ft. Worth WFO 25 April 2005

Forecast: 2003 Z         Forecast: 2003 Z
Radar Image: 2003 Z      Radar Image: 2107 Z
       Ft. Worth WFO 25 April 2005

Forecast: 2020 Z         Forecast: 2020 Z
Radar Image: 2020 Z      Radar Image: 2119 Z
       Ft. Worth WFO 25 April 2005

Forecast: 2030 Z         Forecast: 2030 Z
Radar Image: 2030 Z      Radar Image: 2129 Z
       Ft. Worth WFO 25 April 2005

Forecast: 2042 Z         Forecast: 2042 Z
Radar Image: 2042 Z      Radar Image: 2142 Z
        Ft. Worth WFO 25 April 2005

• This was one of the first events after some
  modifications had been made to the system
  based on forecaster feedback (i.e. a CIN predictor
  field was added to the forecast logic).
• Had this information not been included, the ANC
  system would have produced several hours of
  false alarms prior to storms initiating.
• Several forecasters consulted the system during
  this event and it was used to help with spotter
  activation.
             Our Impressions of the
          Ft. Worth WFO Deployment
• Users have been very accommodating of new
  technology.
• Users have done a really good job of entering
  boundaries.
• Use the system most often early on in the
  convective events during initiation/development
  phase.
• Received a lot of very useful feedback from the
  users.
• Have incorporated some of the forecasters ideas
  which we feel have led to improved forecasts and
  are in the process of implementing others.

				
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