Improved NCEP Products for the Energy Community Jeff McQueen, Jun Du, B' Zhou, B' Ferrier, G' Maniki

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Improved NCEP Products for the Energy Community
Jeff McQueen, Jun Du, B. Zhou, B. Ferrier, G.
Manikin, E. Rogers G. DiMego, H. Juang, Z.
Toth, B. BuaMonday, November 16, 2009
where the nations climate and weather services
begin
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Outline

• Improved Forecast Modeling Systems
• NCEP Short Range Ensemble Forecasts (SREF)
• High Resolution Weather Reseach and Forecast
  System (WRF)
• Rapid Update Cycle Model
• Improved ingest of surface measurements to
  initialize models
• Improved Products
• Higher Fidelity -? Capture smaller scale features
• Improved Accuracy
• Improved probabilistic information to help
  quantify forecast uncertainties
• Gridded Bias Correction

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SREF System Goals

• Improved Spread-Skill relationship Information
• System variance System Mean Squared Error
• Less clustering around control model systems
• Improved or similar skill as determined from
  ensemble mean and probabilistic skill scores for
  1-2 day forecasts (RPSS, Sharpness of
  probabilistic forecast)
• QPF
• Upper-level winds heights
• 2 m Temperature, MSLP
• Improved probabilistic products for NWS mission
  forecasts (Severe storms, Aviation, hydromet,
  ocean, tropical, Energy)

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FY04 SREF Changes

• Increased Resolution
• 48 km to 32 km horizontal resolution
• Increased to 60 levels in Eta Members
• Enhance SREF Physics Diversity by Running Several
  Members with Different Cloud Physics and
  Convective Parameterization Schemes
• 15 members as part of larger NOAA ensemble
• Scaled Breeding System to Control Unrealistically
  Large Initial Condition Perturbations in cold
  season and increase IC perturbations in warm
  season
• Upgrade Eta members to Software Version Level
  Same as July 2003 Eta-12 system
• Upgrade RSM Members with Improved Physics and
  Computational Schemes

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SREF Parallel Physics Members Since March 3, 2004
Model Res (km) Levels Members Cloud
Physics Convection RSM SAS 32 28 Ctl,n,p
GFS physics Simple Arak-Shubert RSM RAS
32 28 n,p GFS physics Relaxed Arak-Shubert
Eta-BMJ 32 60 Ctl,n,p Op
Ferrier Betts-Miller-Janic Eta-SAT
32 60 n,p Op Ferrier BMJ-moist
prof Eta-KF 32 60 Ctl,n,p Op
Ferrier Kain-Fritsch Eta-KFD 32 60 n,p Op
Ferrier Kain-Fritsch with
enhanced detrainment
Similar to Fall-Winter 03-04 parallel system
except Removed poorest performing models (for
qpf) and using scaled breeding
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Dissemination

• Mean, spread, probability files on NCO FTP
• EMC web graphics
• Mean, spread, probs, Individual members,
  profiles,
• SPC Convective probabilistic products
• Mean, spread plots are being added to NCO web
  page
• AWIPS Scheduled for OB6 (April 2005)

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SREF Deterministic Results Surface CONUS RMSE
by Forecast hr (Summer 2004)
2 m Temperature Error
2 m RH
2 m Temperature Bias
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SREF Probabilistic Results Spread Plots (June
12-July 11, 2004)
500H
SLP
850T
850U
250U
850RH
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SREF Probabilistic Results 12h Precipitation-
0.1 threshold (June 12-July 11, 2004)
12 h qpf RPSS
12 h qpf Spread
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SREF Warm Season Case StudyJuly 22, 2004 09 Z
Forecast (51h Forecast)
Operational
Experimental

Increased spread in Enhanced physics- Diversity
system
Precipitation Spread (inches)
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SREF Warm Season Case StudyJuly 22, 2004 09 Z
Forecast (51h Forecast) Prob. Precipgt1 in 48 h
Operational

Experimental
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SREF Warm Season Case StudyJuly 25, 2004 09 Z
Run (12 h forecast)
48 km
Physics Diversity

20C 2m Temp
20C 2m Temp
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Improved Precipitation ForecastSept. 17, 2004
SREF 32km Forecast
Eta-12km Forecast
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SREF Cold Season Case Study March 16, 2004 09Z
Simulation 51 h Forecast
Operational
Experimental
Analysis March 17, 2004 12 UTC
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Ensemble Products
Prob. THIgt75 F
Mean/Spread Surface Pressure
Mean/Spread 2m Temperature
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Summary

• Deterministic results generally positive
• Significant reduction of surface temperature
  errors
• Increased physics diversity resolution and
  scaled breeding improves system spread
• Improved Diversity
• Strongest impact on sensible wx and in Warm
  Season
• Additional scenarios captured
• Initial Condition perturbations capture synoptic
  scale uncertainties well
• Scaled breeding controls unrealistic system
  spread

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SREF Planned 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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Weather Research and Forecasting

• End-to-end Common Modeling Infrastructure
• Observations and analysis
• Prediction model
• Post-processing, product generation and display
• Verification and archive
• For the community to perform research
• For Operations to generate NWP guidance
• USWRP sponsorship - many partners NCAR, NCEP,
  FSL, OU/CAPS, AFWA, FAA, NSF and Navy
• Initial implementation in HiResWindow in 4QFY04
• Ensemble approach to be taken instead of
  single-run deterministic approach

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Nonhydrostatic Mesoscale ModelFeature Comparison
With Meso Eta
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HiResWindow Fixed-Domain Nested Runs

• Users want routine runs they can count on at the
  same time every day
• 00Z Alaska-10 Hawaii-8
• 06Z Western-8 Puerto Rico-8
• 12Z Central-8 Hawaii-8
• 18Z Eastern-8 Puerto Rico-8
• This gives everyone a daily high resolution run
  when fewer than 2 hurricane runs needed

http//www.emc.ncep.noaa.gov/mmb/mmbpll/nestpage/
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Hybrid versus Step (Eta) Coordinates
Ptop
Ptop
? 0
Pressure domain
420 mb
? 0
Sigma domain
? 1
MSL
? 1
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Improved cloud forecasts east of mountains
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Isabel NMM 8 km, 60 lev. GFS data Sea
level Pressure
952 mb Obs. 953 mb
http//www.nhc.noaa.gov/2003isabel.shtml
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HiResWindow Plans
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• Rapid Update Cycle
• Influenced by NEHRT research
• 
  
• 2004 - 20km RUC implementations completed
• April 2004 RUC model
• vertical advection of moisture ? better precip
  and clouds. More detailed land use/coastline.
• September 2004 RUC analysis
• use boundary-layer depth in assimilation of
  surface/METAR obs ? better temp/dewpoint/CAPE
  forecasts

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• RUC changes
• Influenced by NEHRT research
• --------------------------------------------------
  ---------------------------------------------
• 2005 - Implementation of 13km RUC in operations
  at NCEP
• Assimilation of new observations
• - GPS-precipitable water
• ? improved moisture forecasts
• - METAR cloud/vis/current weather
• ? improved cloud/ceiling and precipitation
  forecasts
• - Mesonet
• - 915 MHz boundary-layer profilers, RASS
  temperatures
• Soil moisture/temp nudging
• Model changes New versions of
• - mixed-phase cloud microphysics (NCAR-FSL)
• - Grell-Devenyi convective parameterization
• ? improved precipitation and
  convection forecasts
• 2007 Planned implementation of WRF-based Rapid
  Refresh (new 1-h cycle at 10km replacing
  current RUC)

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13km RUC

• Improvements expected from 13km RUC
• Improved near-surface forecasts
• Improved precipitation forecasts
• Better cloud/icing depiction

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20km RUC
13km RUC
Soil moisture 12z 28 July 2004
More detailed coastline with 13km resolution
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RUC20 vs. RUC13 precipitation forecast
verification September 2004 (verified against
NCEP 24h precip analysis)

• RUC13
• higher equitable threat score
• bias closer to 1
• Why?
• Improved initial conditions
• Improved Grell/Dev conv scheme
• Higher horizontal resolution

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12-h surface forecasts verified vs. METAR obs 1
Sept 2 Oct 2004 20-km RUC (oper) vs. 13-km RUC
- METARs in Eastern half of US (East
of 100 W)
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SREF GRIB formatting fixed for
these probabilistic products
Grid 212 Lambert Conformal 40 km,
185x129 Probabilistic Parameters Units
Threshold____________ Convective Avail.
Pot. Energy J/kg 500, 1000, 2000,
3000, 4000 Convective Inhibition (CIN)
J/kg -50, -100, -200, -300,
-400 Storm Relative Helicity (SREH)
m2/s2 100, 150, 200, 250, 300 Lifted
Index K 0, -2, -4, -6, -8
Precipitation (3, 6, 12, 24 hr)
Inches 0.1, 0.25,0.5, 1.0, 2.0
12hrly Accumulated Snow Fall Inches
1, 2.5, 5, 10, 20 Prob precip type is
rain Prob precip type is
freezing rain Prob precip type is
snow or sleet
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Future ImplementationSREF transition to WRF

• Spring 2005
• 3 WRF-MASS-NCAR (Ctl, P, N) replace EKF
• 2 WRF-NMM-NCAR (P,N) replace EKF
• Confidence factors
• Fall 2005
• 2 WRF-MASS-NCEP (P,N) replace EBMJ
• 3 WRF-NMM-NCEP (Ctl, P,N) replace EBMJ
• Improved Post-processing/Calibration
• 2006
• LSM/PBL perturbations (Zo,moisture, alb)
• GDAS-ETA/WRF members
• Advanced IC perturbations (ETKF)