Climate Diagnostics and Prediction WorkshopState College, PA

October 24-28, 2005

Recent Evolution of the MJO and Description Recent Evolution of the MJO and Description of an Experimental Global Tropics Hazard of an Experimental Global Tropics Hazard

AssessmentAssessmentJon 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 Center2 Climate Diagnostics Center3 NWS, Dodge City, Kansas4 National Hurricane Center

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

OutlineOutline

MJO Activity October 2004 – September 2005MJO Activity October 2004 – September 2005

Overview of MJO Activity -- OLROverview of MJO Activity -- OLR

Overview of MJO Activity – Velocity PotentialOverview of MJO Activity – Velocity Potential

Overview of MJO Activity – 850 mb WindOverview of MJO Activity – 850 mb Wind

Overview of MJO Activity – Oceanic Heat ContentOverview of MJO Activity – Oceanic Heat Content

Warming triggered at onset by a period of persistent westerly wind anomalies

Spring Event – (March – May 2005)Spring Event – (March – May 2005)

Spring MJO Event – CharacteristicsSpring MJO Event – Characteristics MJO phase and amplitude

Multivariate EOF analysis

850 hPa / 200 hPa zonal wind, OLR

(Wheeler and Hendon, MWR, 2004)

Period: ~ 45 days (1st), 30 days(2nd)

Phase Speed: ~ 4.5 m/s (OLR)

Start Phase: Western Indian Ocean

Ending Phase: Africa

Spring MJO Event – Historical ContextSpring 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 AnimationSpring MJO Event – Velocity Potential Animation

Spring MJO Event – Velocity Potential AnimationSpring MJO Event – Velocity Potential Animation

Spring MJO Event – ImpactsSpring MJO Event – ImpactsAbove average rainfall

May 11-20

Heavy rains in Central America and northern South America

Mar 27-Apr 15, May 6-15

Beneficial rains across Indonesia

Apr 26-30

Enhancement in the rainy season in northeast Brazil

Below average rainfallSpring MJO Event – ImpactsSpring MJO Event – Impacts

Apr 6-15

Break in the rainy season in northeast Brazil

May 26-30

Beneficial break in rains across regions in Central America

Exacerbation of existing dry conditions during several time periods

Spring MJO Event – ImpactsSpring MJO Event – Impacts

Tropical Cyclone Development and South Pacific Convergence Zone

1. Tropical cyclones Isang and Adeline-Juliet2. Typhoon Sonca

Early-mid April

Mid-late April

Enhanced SPCZ

Apr 16-25

Winter Event – (December 2004 – January 2005)Winter Event – (December 2004 – January 2005)

Winter MJO Event – OLRWinter 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 windWinter MJO Event – 200 mb wind

Upper-level wind anomalies stretching from the tropics into the southwest United States

Winter MJO Event – California RainsWinter MJO Event – California Rains

Experimental Global Tropics Hazard AssessmentExperimental Global Tropics Hazard Assessment

Background and StatusBackground 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 24. Weekly conference call with our collaborators:

Klaus Weickmann – CDC, Ed Berry – NWS Dodge City, KansasEric 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 1Prototype Product – Outlook with Key – Page 1

1. Hurricane Kenneth and Tropical Storm Norma will impact the east Pacific Ocean2. Increased chance of above average rainfall across west central Africa3. Increased chance of below average rainfall across India and the Bay of Bengal4. Increased chance of above average rainfall in the equatorial Indian Ocean5. Increased chance of tropical cyclone development, Typhoon Longwang will impact the western Pacific6. Increased chance of above average rainfall in the equatorial western Pacific

Outlook: September 26, 2005Week 1

Week 2

1. Increased chance of above average tropical cyclone activity in the western Atlantic and Caribbean Sea region2. Increased chance of above average rainfall in the equatorial Indian Ocean3. Increased chance of below average rainfall in the vicinity of the Philippines

Prototype Product – Discussion – Page 2Prototype 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, 2005With 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.

Forecast Resources Forecast Resources Frequent observational 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 ModelsForecast Resources: Statistical Models

Empirical Wave PropagationNovember 5, 2004

Wheeler ForecastApril 3, 2005

Jones ForecastOctober 3, 2005

Convection forecast to shift eastward Remote signals

also evident

A change in sign of convection is forecast during the period

Forecast Resources: Dynamical Models -- GFSForecast Resources: Dynamical Models -- GFSVelocity Potential

Eastward propagating large scale velocity potential field

Forecast Resources: Monitoring Other Coherent ModesForecast Resources: Monitoring Other Coherent Modes

Consolidation of convection across eastern Indonesia and the far western Pacific

Forecast Resources: Monitoring Other Coherent ModesForecast 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 VerificationInitial Verification Qualitative verification on a case by case basis to date

Weekly average OLR 1ºx1º

Tropical cyclone tracks

April 2005

Planned Quantitative VerificationPlanned 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 climatology2. Long-term: Apply a scaling methodology between datasets in (1)

Create spatial maps for following:

1. Hit Rate2. Threat Score3. Probability of Detection4. False Alarm Rate5. Bias6. Heike Skill Score

Upcoming PlansUpcoming 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?Questions, Suggestions, or Comments?

Spring MJO Event – ImpactsSpring MJO Event – Impacts

Westerly wind anomalies located in the western area of upper level divergence associated with enhanced convection

Easterly anomalies east of enhanced convection

Winter MJO Event – CharacteristicsWinter MJO Event – CharacteristicsDuration: ~ 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 ModelResources: 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