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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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