Hourly Updated NOAA NWP Models
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Transcript of Hourly Updated NOAA NWP Models
35th Conference on Radar Meteorology30 September 2011
Development and Testing of Improved Radar-Data Assimilation Techniques for the Rapid Refresh and High-Resolution
Rapid Refresh (HRRR)
NOAA/ESRL/GSDCurtis Alexander, David Dowell,
Ming Hu, Steve Weygandt, Tanya Smirnova,
Stan Benjamin, John Brown, Eric James and Patrick Hofmann
Hourly Updated NOAA NWP Models
13km Rapid Refresh
(mesoscale)
13km RUC (mesoscale)
3km HRRR (storm-scale)
RUC – current oper Model, new 18h fcst every hour
High-Resolution Rapid Refresh Experimental 3km nest inside RR, new 15-h fcst every hour
Rapid Refresh (RR) replaces RUC at NCEP in 2011 WRF, GSI with RUC features
NOAA/ESRL/GSD/AMB ModelsModel Run at: Domain Grid
PointsGrid
SpacingVertical Levels
Vertical Coordinate
Lowest Level
Pressure Top
RUC GSD, NCO CONUS 451 x
337 13 km 50 Sigma/ Isentropic 5 m ~50 mb
RR GSD,EMC
North America
758 x 567 13 km 50 Sigma 8 m 10 mb
HRRR GSD CONUS 1799 x 1059 3 km 50 Sigma 8 m 85 mb
Model Version Time-Step Forecast Length Initialized Boundary
ConditionsRun Time
# of CPUs
RUC N/A 18 s 18 hrs Hourly (cycled) NAM ~25 min 36
RR WRF-ARW v3.2+ 60 s 18 hrs Hourly
(cycled) GFS ~25 min 160
HRRR WRF-ARW v3.2+ 15-20 s 15 hrs Hourly
(no-cycle) RUC ~50 min 1000
NOAA/ESRL/GSD/AMB Models
Model Version Time-Step Forecast Length Initialized Boundary
ConditionsRun Time
# of CPUs
RUC N/A 18 s 18 hrs Hourly (cycled) NAM ~25 min 36
RR WRF-ARW v3.2+ 60 s 18 hrs Hourly
(cycled) GFS ~25 min 160
HRRR WRF-ARWv3.2+ 18-23 s 15 hrs Hourly
(no-cycle) RR ~50 min 1064
Model Run at: Domain Grid Points
Grid Spacing
Vertical Levels
Vertical Coordinate
Lowest Level
Pressure Top
RUC GSD, NCO CONUS 451 x
337 13 km 50 Sigma/ Isentropic 5 m ~50 mb
RR GSD,EMC
North America
758 x 567 13 km 50 Sigma 8 m 10 mb
HRRR GSD CONUS 1799 x 1059 3 km 50 Sigma 8 m 20 mb
Model Assimilation Radar DFI Microphysics Radiation Cum
Param PBL LSM
RUC RUC-3DVAR Yes - strong Thompson RRTM/Dudhia Grell-
DevenyiBurk-
Thompson
RUC
RR GSI Yes -strong Thompson RRTM/Goddard G3 +
Shallow MYJ RUC
HRRR None: RUC I.C. No Thompson RRTM/Goddard None MYJ RUC
NOAA/ESRL/GSD/AMB Models
Model Assimilation Radar DFI Microphysics Radiation Cum
Param PBL LSM
RUC RUC-3DVAR Yes - strong Thompson RRTM/Dudhia Grell-
DevenyiBurk-
Thompson
RUC
RR GSI Yes -strong Thompson RRTM/Goddard G3 +
Shallow MYJ RUC
HRRR None: RR I.C. No Thompson RRTM/Goddard None MYJ RUC
NOAA/ESRL/GSD/AMB Models
Summary of 2011Changes & Evaluation Activities
(1) RR initialization (parent model/assimilation)(2) Latent heating strength (radar data assimilation) in RR(3) Reduced diffusion (no 6th order diffusion)(4) Raised pressure top(5) Increased min/max time step(6) Higher resolution SST data (0.083°)
HRRR Milestones• Inception over northeastern US
Sept 2007• Integration into CoSPA: Aviation Users
Spring 2008• Domain expansion to eastern US
Mar 2009• HCPF time-lagged ensemble inception May
2009• HRRR WRF-ARW updated to v3.1.1
Oct 2009• Domain expansion to CONUS
Oct 2009• HRRR WRF-ARW updated to v3.2
Apr 2010• Forecast period extended to 15 hrs
Apr 2010• Real-time multi-scale reflect. verification June
2010• Parallel (shadow) retrospective system Sept
2010• Attained ~95% reliability
Jun 2010• Reduced latency to ~2 hrs
Dec 2010
HRRR (and RR) Future Milestones• Conversion of all output to GRIB2 format
Apr 2011• Transition from RUC to RR parent model
Apr 2011• DOE-funded HRRR FTP site for energy industry May
2011• Update to WRF-ARW v3.3.1
Nov 2011• Reflectivity data assimilation at 3 km scale 2012• Assimilate Radial Velocity at 3 km scale
2012• Incorporate SatCast products at 3 km scale 2012• HRRR demo @ESRL improves
2012-2014• Rapid Refresh operational at NCEP
2011• Ensemble Rapid Refresh (NARRE) at NCEP
2014• HRRR operational at NCEP
2015?• Ensemble HRRR (HRRRE) at NCEP
2016?
HRRR (and RR) Future Milestones• Conversion of all output to GRIB2 format
Apr 2011• Transition from RUC to RR parent model
Apr 2011• DOE-funded HRRR FTP site for energy industry May
2011• Update to WRF-ARW v3.3.1
Nov 2011• Reflectivity data assimilation at 3 km scale 2012• Assimilate Radial Velocity at 3 km scale
2012• Incorporate SatCast products at 3 km scale 2012• HRRR demo @ESRL improves
2012-2014• Rapid Refresh operational at NCEP
2011• Ensemble Rapid Refresh (NARRE) at NCEP
2014• HRRR operational at NCEP
2015?• Ensemble HRRR (HRRRE) at NCEP
2016?
Radar Reflectivity Data Assimilation
Model Forecasts (WRF-ARW)
Reflectivity = Diagnostic variable ESTIMATE
Hydrometeors are prognostic variables in microphysics scheme(s)
Radar Observations (WSR-88D)
Reflectivity = SUM(Rain, Snow, Hail, etc…)
Not a direct observation of individual hydrometeors and distributions
Reflectivity observation type does not correspond to a state variable
Options:A. Specification of hydrometeors using some assumptionsB. Use implicit condensate formation as a model forcing functionC. Combination of A and BD. Others
Radar Reflectivity Data AssimilationB. Use implicit condensate formation from > 0 dBZ 3-D reflectivity as aforcing function in the model: Latent heating in microphysics (MP)
(1) Latent heating rate in the absence of reflectivity observationsOutside of radar coverage => Use model MPBelow lowest elevation and above PBL top => Extrapolate obs down
Testing:Rely upon other observation types (lightning, satellite) as proxy
(2) Latent heating rate where 3-D reflectivity observation < 0 dBZConvective/precipitation suppression => Set MP latent heating = 0
Testing:If model environment supports convection this is not enough,Need to force weak subsidence to avoid spurious convection
Radar Reflectivity Data AssimilationB. Use implicit condensate formation from > 0 dBZ 3-D reflectivity as aforcing function in the model: Latent heating in microphysics (MP)
(3) Latent heating rate for a given 3-D reflectivity observation > 0 dBZApplication in planetary boundary layer (PBL)? => No, use MP value
Function of stability? => NoTesting: Reduce heating for more unstable environments
Vertical/horizontal location of heating? => Currently co-locatedTesting: Vertical displacement (i.e. reflectivity trailing indicator)
Time-scale of condensation formation? => Currently 10 minTesting: 5 min (2X), 20 min (1/2 X), 30 min (1/3 X)
Length of time to apply heating? => Currently constant for 20 minTesting: Cycle in four 15-min periods with different values
Adjust microphysics heating rate? => Currently replace (specify)Testing: Averaging or adding obs-based and MP heating
2011 Hourly HRRR Initialization from RR
HourlyRR
LateralBoundaryConditions
Interp to 3 km grid
HourlyHRRR
15-h fcst
Initial Condition
Fields
11 z 12 z 13 z
Time (UTC)
AnalysisFields
3DVARObs
3DVARObs
Back-groundFields
18-h fcst 18-h fcst
1-hrfcst
DDFI DDFI
1-hrfcst
18-h fcst
1-hrfcst
Interp to 3 km grid
15-h fcst
Use 1-h old LBC
to reducelatency
Use most recent IC (post-DFI)
to get latest radar info
Reduced Latency:
~2h for 2011
Forward integration, full physicsApply latent heating from radar reflectivity, lightning data
Diabatic Digital Filter Initialization (DDFI) -20 min -10 min Init +10 min
RR model forecast
Backward integration,no physics
Obtain initial fields with improved balance, vertical circulations associated withongoing convection
• The model microphysics temperature tendency is replaced with a reflectivity-based temperature tendency.– Dynamics and microphysics respond to thermodynamic forcing.
• Analysis noise is reduced by digital filtering.
00 hr HRRR forecasts
RR – No radar data RR – Radar data
Obs00z 12 August 2011
01 hr HRRR forecasts
ObsObs
RR – No radar data RR – Radar data
01z 12 August 2011
RR – No radar data RR – Radar data
Reflectivity00z 12 August 201100 hr forecasts
Convergence Cross-Section
RR – No radar data RR – Radar data
Convergence Cross-Section
Reflectivity01z 12 August 201101 hr forecasts
00 hr HRRR forecasts
RR – No radar data RR – Radar data
Obs20z 14 August 2011
01 hr HRRR forecasts
RR – No radar data RR – Radar data
21z 14 August 2011 ObsObs
RR – No radar data RR – Radar data
20z 14 August 201100 hr forecasts
Reflectivity
Convergence Cross-Section
RR – No radar data RR – Radar data
Convergence Cross-Section
21z 14 August 201101 hr forecasts
Reflectivity
HRRR Reflectivity VerificationDDFI in 13-km RUC/RR (parent model) but not in 3-km HRRR
Eastern US, Reflectivity > 25 dBZ11-20 August 2011
Increase in forecast skill when reflectivity assimilated in parent model
Neighborhood skill apparent on coarser verification grid (right)
CSI 03 km CSI 40 km
RUC + RadarRR + Radar
RUC + No RadarRR + No Radar
RUC + RadarRR + Radar
RUC + No RadarRR + No Radar
HRRR Reflectivity VerificationDDFI in 13-km RUC/RR (parent model) but not in 3-km HRRR
Eastern US, Reflectivity at 03 km11-20 August 2011
Higher bias when assimilating radar data, especially with the RR parent
RR + RadarRR + No RadarRUC + RadarRUC + No Radar
BIAS 25 dBZ BIAS 40 dBZ
RR + RadarRR + No RadarRUC + RadarRUC + No Radar
OptimalOptimal
HRRR Reflectivity VerificationDDFI in 13-km RR (parent model) but not in 3-km HRRR
Eastern US, Reflectivity > 25 dBZ14-24 July 2010
Increased latent heating forcing from parent increases skill and biasIncreased skill not sustained at longer forecast times (> 4 hrs)
CSI 40 km BIAS 03 km
Optimal
2x Latent heating rate in RR1x Latent heating rate in RR1/3x Latent heating rate in RR
2x Latent heating rate in RR1x Latent heating rate in RR1/3x Latent heating rate in RR
2011 Hourly HRRR Initialization from RR
HourlyRR
LateralBoundaryConditions
Interp to 3 km grid
HourlyHRRR
15-h fcst
Initial Condition
Fields
11 z 12 z 13 z
Time (UTC)
AnalysisFields
3DVARObs
3DVARObs
Back-groundFields
18-h fcst 18-h fcst
1-hrfcst
DDFI DDFI
1-hrfcst
18-h fcst
1-hrfcst
Interp to 3 km grid
15-h fcst
Use 1-h old LBC
to reducelatency
Use most recent IC (post-DFI)
to get latest radar info
Reduced Latency:
~2h for 2011
Attempt application of 13-km DDFI again at 3-km
HourlyRR
LateralBoundaryConditions
Interp to 3 km grid
HourlyHRRR
15-h fcst
Initial Condition
Fields
11 z 12 z 13 z
Time (UTC)
AnalysisFields
3DVARObs
3DVARObs
Back-groundFields
18-h fcst 18-h fcst
1-hrfcst
DDFI DDFI
1-hrfcst
18-h fcst
1-hrfcst
Interp to 3 km grid
15-h fcst
Use 1-h old LBC
to reducelatency
Use most recent IC (post-DFI)
to get latest radar info
Reduced Latency:
~2h for 2011
DDFI DDFI
HRRR Reflectivity VerificationDDFI in 13-km RR (parent model) AND in 3-km HRRR
Eastern US, Reflectivity > 25 dBZ14-24 July 2010
Application of DDFI at both scales results in spurious convectionSignificant loss of skill
2x Latent heating rate in RR1x Latent heating rate in RR1/3x Latent heating rate in RR1x Latent heating in RR and HRRR
CSI 40 km BIAS 03 km
Optimal
2x Latent heating rate in RR1x Latent heating rate in RR1/3x Latent heating rate in RR1x Latent heating in RR and HRRR
2011 Hourly HRRR Initialization from RR
HourlyRR
LateralBoundaryConditions
Interp to 3 km grid
HourlyHRRR
15-h fcst
Initial Condition
Fields
11 z 12 z 13 z
Time (UTC)
AnalysisFields
3DVARObs
3DVARObs
Back-groundFields
18-h fcst 18-h fcst
1-hrfcst
DDFI DDFI
1-hrfcst
18-h fcst
1-hrfcst
Interp to 3 km grid
15-h fcst
Use 1-h old LBC
to reducelatency
Use most recent IC (post-DFI)
to get latest radar info
Reduced Latency:
~2h for 2011
13-km DDFI and sub-hourly cycling at 3-km
HourlyRR
LateralBoundaryConditions
Interp to 3 km grid
HourlyHRRR
Initial Condition
Fields
11 z 12 z 13 z
Time (UTC)
AnalysisFields
3DVARObs
3DVARObs
Back-groundFields
18-h fcst 18-h fcst
1-hrfcst
DDFI DDFI
1-hrfcst
18-h fcst
1-hrfcst
Interp to 3 km grid
Reduced Latency:
~1h for 2012?
Use 1-h old IC
and 2-h old LBC
15-h fcst 15-h fcst
Reflectivity DA on 3-km (HRRR) Grid
interpolation from RR,hydrometeor specification
t060 min t045 min t030 min t015 min t0
reflectivity-based temperature tendency
NSSL3D
mosaic
HRRR composite reflectivity
t045 min
t030 min t015 min t0
HRRR (3-km) grid produces convective storms explicitlyReflectivity-based temp. tendencies are applied during sub-
hourly cycling (forward model integration only, no digital filtering)
Initial Temperature atLowest Model Level
(1) HRRR initializedwithout 3-km radar DA
(2) HRRR initializedwith 3-km radar DA
1000
km
2000 UTC 11 May 2011
CompositeReflectivity2100 UTC
11 May 2011
1-h fcstwith 3-km
radar cycling
obsconvection develops quickly (RR cycling,
DDFI)
1-h fcstwithout 3-kmradar cycling
1-h fcstwith 3-km
radar cycling
more accuraterepresentation ofsystem maturity
CompositeReflectivity0200 UTC
11 May 2011
6-h fcstwith 3-km
radar cycling
more accurateforecast of
convective system propagation
6-h fcstwithout 3-kmradar cycling
obs
HRRR Reflectivity VerificationDDFI in 13-km RR (parent model) AND 3-km HRRR 15-min cycling
Eastern US, Reflectivity > 25 dBZSelect Cases May-July 2011
Application of DDFI at 13-km and cycling at 3-km results improves skillRetention of convective-scale forcing/evolution remains a challengeMesoscale environment often dominates storm-scale forcing
1x Latent heating rate in RR and HRRR1x Latent heating rate in RR
CSI 03 km BIAS 03 km
Optimal
2x Latent heating rate in RR1x Latent heating rate in RR1/3x Latent heating rate in RR1x Latent heating in RR and HRRR
CSI 40 km1x Latent heating rate in RR and HRRR1x Latent heating rate in RR
HRRR Forecast Behavior2012 Targets
(1) Lower peak bias in convection over eastern US
(2) Less difficulty propagating/maintaining MCSs
(3) Improve timing convective
initiation (early AM runs)
(4) Fewer false alarm cases
RR/HRRRModelDevelopment andEvaluation
“Simplistic” 13-km latent heatingNo 3-km data assimilation
“Smarter” 13-km latent heating3-km radar data assimilation
2011(1) Higher bias in convection over eastern US
(2) Difficulty propagating/maintaining MCSs
(3) Lead in convective
initiation (early AM runs)
(4) False alarm cases
Implement