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