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Hurricane Model Transitions to Hurricane Model Transitions to Operations at NCEP/EMCOperations at NCEP/EMC
2009 IHC Conference, 2009 IHC Conference, St. Petersburg, FLSt. Petersburg, FL
Robert Tuleya*, Robert Tuleya*,
V. Tallapragada,Y. Kwon, Q. Liu, Zhan Zhang, V. Tallapragada,Y. Kwon, Q. Liu, Zhan Zhang,
Yihua Wu ,J. O’Connor and N. SurgiYihua Wu ,J. O’Connor and N. Surgi
* JHT sponsored
Project Goals and Emphasis Project Goals and Emphasis
• Participate in the yearly operational Participate in the yearly operational implementation of HWRFimplementation of HWRF
• Upgrade HWRF systemUpgrade HWRF system• Trouble shoot problemsTrouble shoot problems• Goal: increase both track and intensity skillGoal: increase both track and intensity skill• Continued collaboration with URI, Florida Continued collaboration with URI, Florida
State, GFDL, and othersState, GFDL, and others
HWRFHWRF Hurricane Hurricane Forecast SystemForecast System
HWRF modelCoupled with POM
NHC storm messagePosition domain
Synoptic fields for many variablesCreate file for track, intensity, etc
Get OBS, Model Inputinitial & boundary conditions
Ocean InitializationInitialize wake, loop currents & eddies
Wrf si (used for topographical parameters)
Wrf real:replace with interpolations from native model data
storm analysis and data ingest 6hr 1st guess
vortex relocation 3DVAR gsi for both nests
Next cycle
HWRF – GFDL HWRF – GFDL Grid configurationGrid configuration 2-nests (coincident)2-nests (coincident) 3-nests(not coincident)3-nests(not coincident)
NestingNesting Force-feedbackForce-feedback Interaction thru intra-nest fluxes Interaction thru intra-nest fluxes
Ocean couplingOcean coupling POM POM (atlantic only)(atlantic only) POMPOMConvective Convective parameterizationparameterization
SAS SAS mom.mix.mom.mix. SAS SAS mom.mix.mom.mix.
Explicit condensationExplicit condensation FerrierFerrier FerrierFerrierBoundary layerBoundary layer GFS non-localGFS non-local GFS non-localGFS non-localSurface layerSurface layer GFDL GFDL ..(Moon et. al.)..(Moon et. al.) GFDL GFDL ..(Moon et. al.)..(Moon et. al.)
Land surface modelLand surface model GFDL slab/GFDL slab/NOAHNOAH GFDL slabGFDL slabDissipative heatingDissipative heating Based on D-L ZhangBased on D-L Zhang Based on M-Y tke 2.5Based on M-Y tke 2.5
Gravity wave drag YESYES NONO
RadiationRadiation GFDL GFDL (cloud differences)(cloud differences) GFDLGFDL
HWRF 2008 SkillHWRF 2008 Skill
Hourly intensity Hourly intensity
Hourly model data Model atcf data
Model variability may be important ?
Season statistics not affectedSeason statistics not affected
Sfc Temperatures Problems in HWRFSfc Temperatures Problems in HWRF remaining b.c. noise??remaining b.c. noise??
1
23
4 (fixed)
Fay 082018Fay 082018Impact of Tsfc fix: Impact of Tsfc fix: (improved track, more intense) (improved track, more intense)
HWRF prod
Tsfc fix
Tsfc fix
HWRF prodHwrf Hwrf
Gustav 083100Gustav 083100Impact of Tsfc fix: Impact of Tsfc fix: (improved track, same intensity)(improved track, same intensity)
Tsfc fix
HWRF prod
HWRF prod
Tsfc fixHwrf
Hwrf
Other potential improvementsOther potential improvements
Surface flux formulations Surface flux formulations Land surface modelingLand surface modeling Gravity wave dragGravity wave drag High resolutionHigh resolution
Reduced Surface DragReduced Surface Drag
Noah LSM studies - Background Noah LSM studies - Background GFDL Slab LSM
1) One level, only predicts surface temperature, wetness is fixed, no runoff
Noah LSM 1) The operational LSM in NCEP's operational mesoscale forecast model (Ek
et al., 2003)2) Multiple soil layers (usually 4 layers: 0-10,10-40, 40-100 and 100-200 cm
depth) with a one-layer vegetation canopy3) Spatially varying root depth and seasonal cycle of vegetation cover
4) Frozen soil physics for cold regions, and improved soil and snowpack thermal conductivity.
5) The Noah LSM predicts soil moisture, soil temperature, land surface skin temperature, land surface evaporation and sensible heat flux, and total
runoff. 6) The HWRF runoff prediction using the Noah LSM can then be used as
forcing input to EMC's Streamflow Routing Scheme (Lohmann et al., 2004). Additionally,
7) The HWRF-Noah forecasts of soil moisture and runoff are good spatial indicators of soil moisture saturation (water logging) and flooding.
HWRF Predicted TracksHWRF Predicted Tracks of Katrinaof Katrina
Obs With/without NOAH LSM
Other sfc & bl physics
12 Hour Accum. Rainfall (mm)12 Hour Accum. Rainfall (mm)
Observed rainfall is the rain gauge measurement
Observed rainfall spreads in larger area than NAM and HWRF rainfall did
HWRFNAMOBS
48h 48h48h
72h 72h72h
Forecasted Stream Flow (mForecasted Stream Flow (m33 s s-1-1))
Influence of orography on the atmosphere
Create obstacles and
additional turbulence
Generation of vertically
propagating gravity waves
Gravity wave drag
Change the large scale flows
Change the track of hurricanes
1. Track forecast skills of HWRF on Eastern Pacific storms are not as good as those on Atlantic storms
2. Diagnotics of HWRF indicates the anomalous flows developed over Mexican Plateau seems to cause the less skillful track forecast of HWRF
3. Proper GWD representation might improve the track forecast of HWRF
4. GWD improved NAM
Motivations
Results NEXT PAGE
No GWD
GWD
~ 50nm improvement at t=120hr
High Resolution HWRF ExperimentHigh Resolution HWRF Experiment
ResolutionResolution - Control: 0.18, 0.06 (~27km, ~9km)- Control: 0.18, 0.06 (~27km, ~9km) - High Res: 0.09, 0.03- High Res: 0.09, 0.03 DomainDomain - Control: 216x432, 60x100- Control: 216x432, 60x100 - High Res: 432x862, 118x198- High Res: 432x862, 118x198
Time StepTime Step - Control: 54, 18 (sec)- Control: 54, 18 (sec) - High Res: 27, 9 (sec)- High Res: 27, 9 (sec) Ocean CouplingOcean Coupling - Coupled with HYCOM (resolution remains the same)- Coupled with HYCOM (resolution remains the same) - Coupling time: every 9 minutes- Coupling time: every 9 minutes Case StudyCase Study - - Hurricane RITA, starting from 2005092012Hurricane RITA, starting from 2005092012
9 km 4.5 km
More banding
4.5km (HRES) HWRF somewhat more accurate
HWRF AccomplishmentsHWRF Accomplishments HWRF severely test in the active Atlantic Season. HWRF severely test in the active Atlantic Season.
HWRF ran in a robust, timely fashion . HWRF HWRF ran in a robust, timely fashion . HWRF competitive with best operational guidance.competitive with best operational guidance.
HWRF installed GWD and fixed sfc temperature issuesHWRF installed GWD and fixed sfc temperature issues HWRF working on LSM, sfc parameterizations, and HWRF working on LSM, sfc parameterizations, and
higher resolution.higher resolution.
HWRF PlansHWRF Plans Upgrade physics, initialization and test ensembles More extensive & quantitative diagnostics Implement new ocean & wave model
The NMM-WRF Modeling SystemThe NMM-WRF Modeling Systemhttp://www.dtcenter.org/wrf-nmm/users/http://www.dtcenter.org/wrf-nmm/users/
Regional-Scale, Moving Nest, Atmospheric Regional-Scale, Moving Nest, Atmospheric Modeling System.Modeling System.
Non-Non-Hydrostatic system of equations formulated Hydrostatic system of equations formulated on a on a rotatedrotated latitude-longitude, latitude-longitude, Arakawa E-grid and Arakawa E-grid and a vertical, pressure hybrid (sigma_p-P) coordinatea vertical, pressure hybrid (sigma_p-P) coordinate..
Advanced HWRF,3D Variational analysis that Advanced HWRF,3D Variational analysis that includes vortex reallocation and adjustment to includes vortex reallocation and adjustment to actual storm intensity.actual storm intensity.
Uses SAS convection scheme, GFS/GFDL Uses SAS convection scheme, GFS/GFDL surface, boundary layer physics, GFDL/GFS surface, boundary layer physics, GFDL/GFS radiation radiation and Ferrier Microphysical Scheme.and Ferrier Microphysical Scheme.
Ocean coupled modeling system (POM GFDL). Ocean coupled modeling system (POM GFDL).
Technical Details of Operational HWRF POM Coupled System run Technical Details of Operational HWRF POM Coupled System run by NCEP Central Operationsby NCEP Central Operations
Total No. of working Scripts Total No. of working Scripts (.sh , *.scr, *.pl files)(.sh , *.scr, *.pl files)
3434
NCO Job Scripts (trigger and queue the NCO Job Scripts (trigger and queue the scripts through schedule maintenance scripts through schedule maintenance software SMS)software SMS)
2929
NCO SMS scripts (driver scripts that provide NCO SMS scripts (driver scripts that provide arguments for *.sh)arguments for *.sh)
2727
Parameter files (namelist files)Parameter files (namelist files) 2525
Working space required for running one 126-Working space required for running one 126-hr HWRF coupled forecasthr HWRF coupled forecast
~50~50 GBGB
Output volume (archived)Output volume (archived) ~4.5~4.5 GBGB
Total run time for end-to-end HWRF forecastTotal run time for end-to-end HWRF forecast ~110 min.~110 min. per forecast per forecast
Max. Resources required per forecastMax. Resources required per forecast 80 processors80 processors (5 nodes on NCEP (5 nodes on NCEP
production machine) for production machine) for 60 min.60 min.
Maximum Number of ForecastsMaximum Number of Forecasts 44 per cycle per cycle
Sporadic SLP noiseSporadic SLP noise
Sea level pressure Sea level pressure diagnosticdiagnostic
Model or post Model or post processing ??processing ??
Traced to grid movementTraced to grid movement
Noise
Eliminate SLP NoiseEliminate SLP Noise
Modify Modify topographic topographic smoothing zonesmoothing zone
Adjust mass Adjust mass fieldsfields
No more Noise !No more Noise !
LGM
Background (2)Background (2)
The GFDL Slab LSM is the default in HWRF:1. The initial soil moisture remains fixed in time
during the HWRF forecast. 2. Moreover, the initial conditions of soil moisture in
the Slab LSM are a fixed field that never change throughout the year and thus are unable to capture antecedent soil moisture conditions.
3. The Slab LSM does not predict the runoff response to HWRF precipitation forecasts, thus cannot predict streamflow from HWRF forecasts.
Why do we need GWD parameterization?
NWP models use grid-averaged (smoothed) terrain data
Coarse resolution models ( > 4km) cannot resolve the GWD caused by
subgrid scale topography
HWRF Track SkillHWRF Track Skill Competitive with other Competitive with other
guidanceguidance Better than GFDL & Better than GFDL &
NGAPSNGAPS GFS & UKMET quite GFS & UKMET quite
goodgood Few long lasting storms Few long lasting storms
in 2007in 2007 EPAC HWRF not as EPAC HWRF not as
goodgood
HWRF
HWRF Intensity SkillHWRF Intensity Skill Competitive with other Competitive with other
guidanceguidance Some improvement Some improvement
over GFDL at early over GFDL at early timestimes
Not a good year for Not a good year for dynamic models after dynamic models after accounting for landfallaccounting for landfall
EPAC intensity EPAC intensity degraded-no ocean degraded-no ocean couplingcoupling
HWRF