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U N I T E D S T A T E S D E P A R T M E N T O F C O M M E R C E

N A T I O N A L O C E A N I C A N D

A T M O S P H E R I C A D M I N I S T R A T I O N

Subseasonal to Seasonal Prediction: CPC Operational Outlooks and Other

Applications Jon Gottschalck

Acting Chief, Operational Prediction BranchNWS / NCEP / Climate Prediction Center

International Conference on Subseasonal to Seasonal PredictionCollege Park, MD

February 10-13, 2014

N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N

Outline• Brief commentary on applications perspective of S2S

• CPC operational outlooks spanning S2SForecast horizons Week-2, Monthly and Seasonal outlooksOutlook types Drought, Extremes

• Other S2S applications perspectives

• CPC ongoing and planned work relevant to S2S


• Brief commentary on applications perspective of S2S





Applications Perspective of S2S• The demand for short-term climate information is growing

exponentially

• Wide range of disciplines and sectors are inquiring since weather and climate affect nearly everything in our planning

• Real world decisions are actively being made every day using S2S climate information, often inappropriately out of necessity

• Define S2S for this discussion as info from Week-2 out to a season


Applications Perspective of S2S• Energy sector requires advanced lead time for extended periods of

much above- or below-normal temperatures

• Need to stage resources, minimize economic losses due to extremes


Applications Perspective of S2S• Typhoon Haiyan in Philippines

• Aid organizations need probabilistic outlooks for tropical cyclone activity at subseasonal lead times (before and after)

• Often need to stage resources or understand risk of additional high impacts weather events during recovery efforts


Applications Perspective of S2S• The water resources sector needs information on drought tendency

(worsening or improving) at seasonal lead times

• Drought in Southwest and Plains during 2011


CPC Subseasonal to Seasonal Outlooks

Outlook Variables Type Frequency Release Date and TimeDays 8-14 Temp/Precip Probabilistic Daily Daily 3 PM ET

Monthly Temp/Precip Probabilistic 2x per month 3rd Thurs of month / Last day of month

8:30 AM, 3 PM ET

Seasonal Temp/Precip Probabilistic 1x per month 3rd Thursday of month

8:30 AM ET

Monthly drought

Drought tendency

Categorical 1x per month Last day of month 3 PM ET

Seasonal drought

Drought tendency

Categorical 1x per month 3rd Thursday of month

8:30 AM ET

U.S. Hazards

Temps, precip, winds, etc.

Categorical Daily Monday - Friday 3 PM ET

Global Tropics, Africa, etc.

Precip, TCs, etc.

Categorical Weekly Tuesday or Wednesday

12 PM ET


Week-2 Outlook


Week-2 OutlooksForecaster considerations:•Overall model system agreement•Ensemble spread•Run-to-run continuity, outliers•Consistency with tropical forcing?•Slowly evolving boundary conditions (snow, soil moisture, local SSTs)


Week-2 OutlooksESRL Reforecast – Hindcast Calibration NAEFS –Recent Conditions Calibration


Monthly and Seasonal Outlooks

Monthly

Seasonal


Forecast Guidance(1) ENSO and MJO(2) Snow cover, soil

moisture, local SSTS(3) Statistical guidance

• CCA• Constructed analogues• Trends

(4) Dynamical guidance

Climate Forecast System (CFS)


MJO Prediction is One Thing

U.S. CLIVAR MJO Working Group and MJO Task Force adopted this metric as a uniform diagnostic for MJO identification,skill evaluation and display of MJO forecasts

MJO Task Force

•Yellow Lines: 20 Individual Members, Green Line: Ensemble Mean • RMM1 and RMM2 values for the most recent 40 days and forecasts for

the next 30 days• Light gray shading: 90% of forecasts, dark gray shading: 50% of

forecasts

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

Realtime data contributions to CPC from operational international centers


MJO Teleconnection is Another

Rainfall,

Diabatic

Heating

Theoretical dispersion model Lagged 200-hPa height MJO composites

JFM MJO Simultaneous Temperature composites


Boundary Forcings

Soil moistureSnow cover

Local SSTs


ENSO and Seasonal Outlook

National Multi Model Ensemble


Drought Outlooks• Drought category tendency outlooks (monthly and seasonal)

• Range of timescales used:

--Short-, medium-, extended-and long-range model guidance and forecast tools

--CPC extended range, monthly and seasonal outlooks

• Impact of climatological wet and dry seasons also play a role


Extremes• High demand for probabilistic information for the tails of the distribution• Stakeholders can make decisions and act on far from perfect information• Prefer to see low probabilities on maps so they are not surprised

Extreme Forecast Index (EFI)CPC Days 8-14 U.S. Hazards Outlook


Extremes

• Identification and prediction of coherent tropical subseasonal and seasonal variability are important for S2S TC prediction

• MJO and ENSO but also atmospheric Kelvin waves, equatorial Rossby waves, etc.

CFS tropical cyclone guidance


Hungry Private Sector• The private sector is a tremendous user of S2S climate information

(especially data)

• Willing to pay and have large staffs to process, display and interpret S2S data from numerous sources to provide actionable information to their clients

• Demand is international with sectors in the energy, financial, agriculture and water resources industries trying to find an edge


Attribution• Another key application of S2S information is better understanding

of persistent short-term climate events that produce large impactsCan a predictable forcing be identified?

Is this purely natural variability?

Can we learn anything from this?

30 day average

60 day average90 day average


Interpretation and Communication

• There is an increasing need for S2S climate information to be properly interpreted / communicated to the public

• The advent of social media and the 24/7 news cycle have often made S2S information front page news

• This can be a hardship at times for operational centers, but it is an important opportunity


CPC Work Related to S2S• Development of an objective, skill weighted consolidation for 500-hPa height, temperature and precipitation Week-2 official outlooks

• Development of a probabilistic Week-2 U.S. Hazards outlook

• Assessment of the predictability of the AO, MJO teleconnection and Arctic sea ice in the Climate Forecast System

• Inclusion of the NMME into the official CPC seasonal temperature and precipitation consolidation


Toward Week 3-4 Official Outlooks?

Week-2 1-3 months

Week 3-4??

Courtesy David Novak, WPC


Toward Week 3-4 Official Outlooks?

• CPC has as a major goal in its 5-year strategic plan to develop official Week 3-4 operational outlooks

• Many challenges to overcome

Is there a scientific basis for a forecast at this time horizon?

If so, would they be reliable? What would be the frequency and

format of a product?

• Determining the inventory of information relevant to this forecast time horizon

CFS Week-3 500-hPa forecast


Summary• The demand for short-term climate information is huge and

includes raw data, outlooks, interpretation and attribution, spanning many sectors both domestically and internationally

• CPC has numerous operational outlooks that span the S2S outlook horizon with a set launch schedule

• CPC is actively evaluating the prospects for experimental Week 3-4 operational outlooks over the next 1-3 years


Questions and Comments

Thank you for your attention

Feel free to contact me anytime via e-mail if you have comments or questions.

[email protected]

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