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Getting Ready for Winter: An NCEP Update

“Where America’s Climate, Weather and Ocean Services Begin”

Louis W. UccelliniDirector, NCEP

Northeast Regional Operational WorkshopAlbany, New YorkNovember 2, 2004

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Outline

• NWS Seamless Suite of Products• New Climate Forecast System: Seasonal Climate Prediction• 6-10 day forecasts• 4-7 day gridded forecasts• 1-3 day range: Winter Weather Desk• NCEP Update

– Computer– Building– Collaborative Activities/Test Beds

• Summary

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New CFS

CD 6-10 Day Forecast Upgrade

DGEX + HPC support for Days 4 -7

HPC Winter Weather Desk Days 1-3

The NCEP coupled Climate Forecast System (implemented August 24, 2004)

1. Atmospheric component• Global Forecast System 2003 (GFS03)

• T62 in horizontal; 64 layers in vertical

• Recent upgrades in model physics Solar radiation (Hou, 1996) cumulus convection (Hong and Pan, 1998) gravity wave drag (Kim and Arakawa, 1995) cloud water/ice (Zhao and Carr,1997)

2. Oceanic component• GFDL MOM3 (Pacanowski and Griffies, 1998)

• 1/3°x1° in tropics; 1°x1° in extratropics; 40 layers

• Quasi-global domain (74°S to 64°N)

• Free surface3. Coupled model

• Once-a-day coupling

• Sea ice extent taken as observed climatology

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Coupled Model Simulation ENSO SST cycles

Simulated 2002-2040 (top)

Observed 1965-2003(bottom)

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Latest CPC Forecast: Weak El Nino conditions are expected to continue into early 2005.

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Without skill mask

CFS SeasonalPrecip Forecast

(mm/month)

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With skill mask

• If anomaly correlation between forecast and observed conditions over the 1982-2003 period is below 0.3, values are not shown

CFS SeasonalPrecip Forecast

(mm/month)

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Without skill mask

CFS SeasonalPrecip Forecast

(mm/month)

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With skill mask

• If anomaly correlation between forecast and observed conditions over the 1982-2003 period is below 0.3, values are not shown

CFS SeasonalPrecip Forecast

(mm/month)

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CPC Winter Season Forecast

2004-05

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CDC Calibration of 1998 MRF

• Dynamical models of the atmosphere all contain biases (differences between model and atmosphere climatologies) and systematic errors which are flow-regime dependent.

• These errors cause the model to make forecasts which are, for example, too dry/wet, warm/cold in comparison with what is observed.

• The errors described above cause the probability forecasts from ensemble models to be“uncalibrated” in comparison with nature. This means that when we look at model forecasts, we find that the probabilities predicted for wet or dry, warm or cold, do not happen in nature with the same frequency.

• CDC’s reforecast calibration greatly reduces this calibration error.

Upgrade to the 6–10; 7–14 Day Forecast

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CDC Calibration

• To calibrate the MRF, CDC re-ran the 15-member ensemble of the model over a 23 year period and compared the probability forecasts from the model with the frequencies of events (wet/dry, warm/cold) in nature.

• This leads to rules for correcting future, real-time probability forecasts from this model.

• CDC automated approach for temp/precip is as good or better than official forecast during 1 year test period

• Operational implementation Sept 04

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6-10 day forecastValid Nov 2 – 6, 2004

Temperature

Precipitation

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4-7 Day Gridded Forecast

• The following grids are being generated daily

• Experimental grids can be viewed here– http://www.hpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html

• Production Methodology documentation– http://www.hpc.ncep.noaa.gov/5km_grids/medr_5km_methodology.pdf

• All grids extend offshore to cover the coastal waters• Verification program underway

– Maximum temperature

– Minimum temperature

– 12 hour PoP

– 6 hourly dew point

– 6 hourly wind (direction and speed)

– 6 hourly cloud cover

– 12 hourly weather

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4-7 Day Gridded Products

Max Temp Min Temp

7 Day Forecast Valid November 3, 2004

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Focus on Winter Weather

Goals of 3 year experiment from 2001- 2004: Improve Winter Weather Services to the public through

coordination of the winter weather watches/warnings with National guidance products

Test Short Range Ensemble Forecast (SREF) system for applications to winter weather forecasting

Motivation: Jan 24-25, 2000; December 30, 2000: March 4-6, 2001

NWS Winter Weather Desk

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NWS Winter Weather Desk

Time line: Sep 15 – April 1 Participants

NCEP HPC Provide SREF based Winter Wx guidance Collaborate with WFOs (Chat Room Technology)

WFOs All CONUS WFOs Use guidance from NCEP to produce coordinated Winter Storm Watches/Warnings

Products: http://www.hpc.ncep.noaa.gov/wwd/winter_wx.shtml 24 h probability (low, moderate, high) of meeting/exceeding 4”, 8”, 12”

snow, 0.25” freezing rain (for day 1, 2, 3) 72h Low tracks graphic and discussion

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Winter Weather Desk Products

• Indicate the probability (potential) for a location to receive specific

thresholds of accumulated snow or ice. • Snowfall - lines represent the probability (low, moderate, and high)

that enclosed areas will receive equal to or greater than a specific threshold accumulation (4", 8" or 12") of snowfall in a 24 hour period.

• Freezing Rain - depicts the probability in the same manner and time period as snowfall, but with an accumulation threshold of .25" (one quarter of an inch) of freezing rain.

PROBABILITY GRAPHICS FOR SNOW AND FREEZING RAIN

Prob > 4” Prob > 8”

Prob > 12” Prob > 0.25”

Day 1

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Winter Weather Desk Products

• Depicts the forecast location and central pressure of significant surface

lows impacting the 48 contiguous United States in 12 hour increments out to 72 hours into the future.

• The low position and track forecast by the meteorologist at NCEP HPC is depicted in black.

• About 20 different computer model forecasts of low position for a given time period are depicted with symbols.

• Provides a user both the preferred position and track of the low and a sense of the uncertainty with

the forecast.

LOW TRACKS GRAPHIC

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Dec 6-7 2003 Event

• Ranked 15th on all time ALY snowstorm list

• Very little Snow in E NY/W NE in NOV

• First week of December featured a major event

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NCEP HPC WWE Guidance

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NCEP HPC WWE Guidance

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Regional Statistics

ER WWE1 WWE2 WWE3

# WFOs 8 23 23

POD .89 .90* .92*

FAR .33 .30 .32

CSI .62 .65 .64

LT–Warn 13 15* 18*

* Broke previous ER regional record

Trend of ER WWE WFO stats

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Short Range Ensemble Forecast

15 members twice per day 63 hrs from 9 and 21Z Resolution upgraded

August 2004 To 32 km from 48 To 60 levels from 45

Mean and spread charts available for forecaster use Most intensive use is in production of probability of

snow and ice accumulations product http://wwwt.emc.ncep.noaa.gov/mmb/SREF/SREF.html

0.25” prcp

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Planned SREF Upgrades

Summer 2005• Run SREF 4 times per day (03, 09, 15 and 21 UTC)

• Improved and new products (Convective, Aviation, Tropical, Energy)

• Output SREF forecasts for Alaska

• Implement Grid Based Bias Correction

• Improve Probabilistic FVS verification

• Develop Confidence Factors for forecasts

• Add 5 WRF members

• Add RSM BUFR files

• Common WRF post-processor

• Implement ensemble mean BUFR files

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NCEP Update

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•Receives Over 123 Million Global Observations Daily•Sustained Computational Speed: 450 Billion Calculations/Sec•Generates More Than 5.7 Million Model Fields Each Day•Global Models (Weather, Ocean, Climate)•Regional Models (Aviation, Severe Weather, Fire Weather)•Hazards Models (Hurricane, Volcanic Ash, Dispersion)•2.4x upgrade operational by mid-January, 2005•Backup in Fairmont, WV operational by mid-January, 2005

Computing Capability

Commissioned/Operational IBM Supercomputer in Gaithersburg, MD (June 6, 2003)

$20M/Year $20M/Year InvestmentInvestment

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NCEP’s Future Location

Current LocationNOAA Science Center

World Weather BuildingCamp Springs

New LocationNOAA Center for

Weather and Climate PredictionUMD Research Park, College Park

(Early FY08)

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NCEP’s Future Location

NOAA Center for Weather and Climate Prediction

UMD Research Park, College Park(Early FY08)

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NOAA Center for Weather and Climate Prediction

o Lease build-to-suit facility with 268,762 sq ft o House 800 staff

o Federal employees, contractors, visiting scientists

o 40 spaces for visiting professors and students

o From the World Weather Buildingo National Weather Service’s (NWS) National Centers for

Environmental Prediction (NCEP)o National Environmental Satellite, Data, and Information Service’s

(NESDIS) research and satellite serviceso From Silver Spring

o Office of Oceanic and Atmospheric Research’s (OAR) Air Resources Laboratory (ARL)

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NCEP Test Beds

• Developmental Test bed Center (EMC)• Climate Test Bed (EMC, CPC)• USWRP/Joint Hurricane Test Bed (TPC)• Hazardous Weather Forecast Test Bed (SPC) • Aviation Test Bed (AWC)• USWRP/Hydrometeorological Test Bed (HPC) (in

progress)• Joint Center for Satellite Data Assimilation

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Summary

• NWS/NCEP’s Seamless Suite of Products from S/I forecasts to daily support for WFO watch/warning responsibilities have been upgraded– Based on new research results– Enhanced modeling capabilities– Systematic implementation and test of a “collaborative

forecast” approach

• NCEP’s infrastructure needs – computer, building, staff – are being addressed

• NCEP will continue to make advanced products readily available

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Background Slides

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