The Recent Evolution of the MJO and Description - Climate

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					Recent Evolution of the MJO and Description
 of an Experimental Global Tropics Hazard
                Assessment
Jon Gottschalck1, Vern Kousky1, Wayne Higgins1, Marco Carrera1,
Klaus Weickmann2, Ed Berry3, Eric Blake4, Chet Schmitt1, Brad
Pugh1, Wanqiu Wang1, Kyong-Hwan Seo1, Michelle L’Heureux1,
Qin Zhang1, Wassila Thiaw1,Wei Shi1, Huug van den Dool1
                      1 Climate Prediction Center
                      2 Climate Diagnostics Center
                      3 NWS, Dodge City, Kansas
                      4 National Hurricane Center




        Climate Diagnostics and Prediction Workshop
                     State College, PA

                     October 24-28, 2005
                                 Outline
 Review of MJO Activity October 2004-September 2005

      1. Overview of the MJO

      2. Details of two MJO events (spring, mid-winter)

 Experimental Global Tropics Hazard Assessment

      1. Description and Prototype Product

      2. Methods and Forecast Tools

      3. Verification

      4. Upcoming Plans
MJO Activity October 2004 – September 2005
Overview of MJO Activity -- OLR
Overview of MJO Activity – Velocity Potential
Overview of MJO Activity – 850 mb Wind
Overview of MJO Activity – Oceanic Heat Content




                                  Warming triggered at onset
                                  by a period of persistent
                                  westerly wind anomalies
Spring Event – (March – May 2005)
              Spring MJO Event – Characteristics
 MJO phase and amplitude            Period:        ~ 45 days (1st), 30 days(2nd)
 Multivariate EOF analysis          Phase Speed:   ~ 4.5 m/s (OLR)
 850 hPa / 200 hPa zonal wind, OLR Start Phase:    Western Indian Ocean
 (Wheeler and Hendon, MWR, 2004) Ending Phase:     Africa
Spring MJO Event – Historical Context




                               Spring 2005 MJO
                               activity




                               Greatest seasonal
                               MJO activity during
                               the last several years
                               dating back to 1997
Spring MJO Event – Velocity Potential Animation
Spring MJO Event – Velocity Potential Animation
                Spring MJO Event – Impacts
 Above average rainfall




                                                Mar 27-Apr 15, May 6-15
        May 11-20


                               Apr 26-30




Heavy rains in                                         Beneficial rains
Central America           Enhancement in               across Indonesia
and northern South        the rainy season
America                   in northeast Brazil
                Spring MJO Event – Impacts
Below average rainfall




        May 26-30

                           Apr 6-15




                                               Exacerbation
Beneficial break                               of existing dry
in rains across          Break in the rainy    conditions
regions in Central       season in northeast   during several
America                  Brazil                time periods
                    Spring MJO Event – Impacts
Tropical Cyclone Development and South Pacific Convergence Zone



                                                   Mid-late April




                                                                  Apr 16-25

                                                Early-mid April




1. Tropical cyclones Isang and Adeline-Juliet
2. Typhoon Sonca                                            Enhanced SPCZ
Winter Event – (December 2004 – January 2005)
Winter MJO Event – OLR

                Enhanced convection
                associated with the MJO shifts
                eastward from Indonesia to
                near the date line.




                 Moisture plume across
                 Hawaii and into southern
                 California.
           Winter MJO Event – 200 mb wind




Upper-level wind anomalies stretching from the
tropics into the southwest United States
Winter MJO Event – California Rains
Experimental Global Tropics Hazard Assessment
                      Background and Status
 MJO weekly update since summer of 2004

        1. Assess and predict the MJO
        2. Discuss evolution  Increasing interest / emphasis on impacts

 Global Tropics Benefits/Hazards Assessment

1. Prototype product  3 page PDF (outlook, discussion, cumulative verification)
2. Physical basis: ENSO, MJO, other coherent and/or persistent anomalies
3. Above/below average precipitation, tropical cyclones, etc.  weeks 1 and 2
4. Weekly conference call with our collaborators:

        Klaus Weickmann – CDC, Ed Berry – NWS Dodge City, Kansas
        Eric Blake, Richard Pasch – NHC, Bill Boos – MIT

5. Outlooks are consistent with US / Africa Hazards and NHC / JTWC forecast tracks
Prototype Product – Outlook with Key – Page 1
                        Outlook: September 26, 2005
      Week 1




      1. Hurricane Kenneth and Tropical Storm Norma will impact the east Pacific Ocean
      2. Increased chance of above average rainfall across west central Africa
      3. Increased chance of below average rainfall across India and the Bay of Bengal
      4. Increased chance of above average rainfall in the equatorial Indian Ocean
      5. Increased chance of tropical cyclone development, Typhoon Longwang will impact the western Pacific
      6. Increased chance of above average rainfall in the equatorial western Pacific
      Week 2




      1. Increased chance of above average tropical cyclone activity in the western Atlantic and Caribbean Sea region
      2. Increased chance of above average rainfall in the equatorial Indian Ocean
      3. Increased chance of below average rainfall in the vicinity of the Philippines
              Prototype Product – Discussion – Page 2
  Forecast reasoning and basis for outlook areas

  Information related to regions and/or impacts not placed on outlook maps (lower confidence)

  Discussion: September 26, 2005
With ENSO neutral conditions continuing, the amplitude/phase of the MJO remains the dominant forcing across the global tropics. During the
last week, the MJO remained weak but there are signs that the MJO may strengthen during the next few weeks.

Currently, the enhanced phase of the MJO is located in the western hemisphere with weak upper-level divergence mainly situated across the
Atlantic and Africa regions. The suppressed phase stretches from the Indian Ocean to the eastern Pacific Ocean. Above average SSTs, however,
have aided the redevelopment of convection in the eastern Indian Ocean and the far western Pacific despite the large scale upper-level
convergence in these areas. Hurricane Kenneth and tropical storm Norma continue to impact the eastern Pacific Ocean while Typhoon
Longwang is slowly moving to the west towards Asia.

During the next 1-2 weeks we expect an increase and expansion of convection from the eastern Indian Ocean into the far western Pacific as a
result of a few factors. Above average SSTs will continue to support enhanced convection in these areas while the residual enhanced phase of
the MJO propagating eastward from the western Hemisphere will interact with other modes of intraseasonal variability and result in a
consolidation of convection in the region. There is a high level of uncertainty, however, of how quickly this area of enhanced convection will
propagate eastward. Statistical model forecasts are mixed in how quickly this area propagates east while the GFS dynamical model depicts are
more rapid shift. Based on the scenario described above we expect above average rainfall during week 1 across western Africa as a result of the
remaining enhanced phase of the MJO and in smaller areas in the eastern Indian Ocean and far western Pacific primarily due by local SSTs. We
anticipate a larger region of above average rainfall by week 2 in the eastern Hemisphere.

Drier than average areas are expected across India and the Bay of Bengal during week 1and later in week 2 in the vicinity of the Philippines as
the weakening suppressed phase of the previous MJO event continues to evolve.

In the near term (week 1), areas in the eastern Pacific will continue to be impacted by tropical cyclones. Hurricane Kenneth will move east of
Hawaii and tropical storm Norma off the west coast of Mexico. Also, Typhoon Longwang will move east towards China and Taiwan and is
expected to produce substantial rainfall, wind, and wave action concerns in these areas late during week 1. Due to continued positive SST
anomalies and low vertical wind shear we expect the threat of tropical cyclone activity to remain higher than average across the western Pacific
throughout the period.
 Frequent observational        Forecast Resources
monitoring (satellite review,
SST, etc.)

 ENSO composites

 MJO composites

 Statistical MJO forecasts

 Dynamical forecasts

 Frequent monitoring of
other coherent tropical
modes of variability

 Synoptic–Dynamic
Model of subseasonal
variability (Weickmann and
Berry, 2005)
              Forecast Resources: Statistical Models

Empirical Wave Propagation        Wheeler Forecast           Jones Forecast
   November 5, 2004                April 3, 2005             October 3, 2005




                      Convection forecast                      A change in sign of
                      to shift eastward     Remote signals     convection is forecast
                                            also evident       during the period
Forecast Resources: Dynamical Models -- GFS
        Velocity Potential




                               Eastward propagating
                               large scale velocity
                               potential field
Forecast Resources: Monitoring Other Coherent Modes



                                 Consolidation of convection
                                 across eastern Indonesia and
                                 the far western Pacific
Forecast Resources: Monitoring Other Coherent Modes


                                A fast moving atmospheric
                                Kelvin wave aids in the
                                development of several
                                tropical cyclones in the
                                eastern Pacific during
                                September
                            Initial Verification
 Qualitative verification on a case by case basis to date   April 2005




                                                                Weekly average
                                                                OLR 1ºx1º




      Tropical cyclone tracks
                Planned Quantitative Verification
 Evaluate rainfall regions and tropical cyclone development outlooks

 Utilize CMORPH, CMAP, OLR global gridded datasets to verify precipitation

    1. Short-term: CMORPH weekly data with CMAP climatology
    2. Long-term: Apply a scaling methodology between datasets in (1)

 Create spatial maps for following:

                         1. Hit Rate
                         2. Threat Score
                         3. Probability of Detection
                         4. False Alarm Rate
                         5. Bias
                         6. Heike Skill Score
                            Upcoming Plans
 Fully incorporate the use of GIS software

 Release experimental combined product via WWW

 Finalize verification strategy and verify forecasts from Mar 2005 - Feb 2006

 Continue to expand collaboration / users  monitoring and research areas

 Accelerate research component

     Develop additional objective input  Clear link with NOAA CTB
Questions, Suggestions, or Comments?
Spring MJO Event – Impacts


                                  Easterly anomalies
                                  east of enhanced
                                  convection



              Westerly wind anomalies located in
              the western area of upper level
              divergence associated with enhanced
              convection
          Winter MJO Event – Characteristics
                                          Duration:        ~ 30 days
                                          Phase Speed: ~ 4.5 m/s (OLR)
                                          Start Phase:   Indian Ocean
                                          Ending Phase: Western Pacific Ocean




Brown and blue lines indicate MJO event
Resources: Synoptic-Dynamic Model

                 Model of sub-seasonal variability

                 Core is based on four stages based on the
                MJO recurrence time

                 Focus on circulation changes and
                extreme events

                 Global and zonal atmospheric angular
                momentum important

                 Weickmann and Berry, J. Climate, 2005

				
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posted:11/1/2011
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