1 Naomi Surgi and the HWRF Team NCEP/Environmental Modeling Center WHERE AMERICA’S CLIMATE AND WEATHER SERVICES BEGIN

2 HWRF TEAM Naomi S., Qingfu L., Vijay T., Young K., Bob T., Zhan Z. and Janna O’C, H.-S. Kim (&MMB) Also, many thanks to Isaac G. & URI lab

3 Overview HWRF ’08 implementation 2008 HWRF end-of-the-season performance 2009 HWRF upgrades The Advanced HWRF HWRF to the Community (DTC/Boulder)

4 HWRF ’08 implementation  HWRF Analysis Changes:  Improved initialization of weak storms  Dynamical Balance: surface pressure adjustment based on gradient wind stream function (more accurate)  Changes to POM initialization:  Feature based assimilation of mesoscale oceanic features  Assimilate more than one warm core rings as well as cold core rings  Rings can be assimilated close to the loop current  HWRF Physics changes / Bug fixes:  Initialize TKE to zero (HWRF does not use TKE based PBL)  Adjustment of temperature and pressure fields after nest motion to remove noise at the lateral boundary of nest domain  HWRF Script Changes:  Improved functionality of all HWRF scripts  HWRF scripts for EMC parallels are consistent with operational configuration  Test results follow

5 Reduced intensity forecast errors (mostly due to reduced negative bias) 2007 HWRF 2008 HWRF Intensity Error [Dennis, Katrina, Rita, Wilma, Dennis] 2007 HWRF vs 2008 HWRF & GFDL

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7 Improved Track Forecast Errors 2007 HWRF Atlantic Track Error [Dennis, Katrina, Rita, Wilma, Dean] 2007 HWRF vs 2008 HWRF 2008 HWRF

HURRICANE SEASON REVIEW How did we do? ATLANTIC

9 HWRF track forecast errors are comparable to those from GFDL and GFS for the Atlantic Atlantic Track Error 2008 HWRF & 2008 GFDL & GFS

10 Atlantic Intensity Error 2008 HWRF & GFDL GFDL HWRF

11 BERTHA (02L) GFDLHWRF

12 HWRF taking Fay to Gulf

13 HWRF GFDL Gustav (07L)

14 HWRF GFDL Ike (09L) Ike One of the difficult 2008 storms for HWRF

15 Ike – northward turn into Fl during early stages of forecast Sept. 05, 00Z 24 hrs later…. Sept. 06, 00Z

16 48 hrs later…. Sep Z 48 hrs later…. Sep Z

HURRICANE SEASON EASTERN PACIFIC

18 EPAC Track Error 2008 HWRF & 2008 GFDL & GFS HWRF, GFS still have some problems in the Eastern Pacific track forecasts

19 Positive intensity bias in the early stages of HWRF forecasts EPAC Intensity Error 2008 HWRF & 2008 GFDL

20 HWRF GFDL Norbert (15E)

HWRF IMPLEMENTATION Refine Hurricane Initialization (Q. Liu) Gravity Wave Drag Parameterization (Kwon) Bug Fix for Cooler Land Surface Temperatures in the inner domain (Tuleya, Zhang) Upgraded GSI (Derber et al.) HWRF experimental design and testing (Tallapragada) Parallel runs HWRF-HYCOM Coupled System (H-S Kim, MMAB) Sea Spray Parameterization (Fairall, Bao) Data Assim. for hurricane core (Mingjing)

22 No GWD GWD ~ 50nm improvement at t=120hr AC EPAC Gravity Wave Drag

23 HWRF H209 HWRF Improved track in EPAC All upgrades

24 H209 HWRF

25 Slight degradation

26 H209 HHWRFR F HWRF Loss of skill bet 36 & 84 hrs.

27 GFS w/New GSI Oper. GFS

28 HWRF-HYCOM Experiments Configuration of HWRF-HYCOM coupled system is complete. HYCOM better represents the Ocean physics than POM. However, there is a cold bias in SST, possible due to heat budget and wind stress Preliminary results show weaker storms in the Atlantic. Work in progress. Improved version of HWRF-HYCOM slated to go in parallel FY 2009.

Doppler Radial velocities Reflectivity Mesoscale Data Assimilation for Hurricane Core Advancing the HURRICANE WRF System Atm. Model physics and resolution upgrades (continuous) Atm/ocean boundary layer, enthalpy fluxes Atm/ocean boundary layer, enthalpy fluxes Microphysics, radiation Microphysics, radiation Incr. Res: 4-6km/100L? Incr. Res: 4-6km/100L? Land surface Coupling Land surface Coupling Waves: multi-grid/surf-zone physics Ocean: 4km. - continuous upgrades in Ocean Data Assimilation. Hi-Res Multi-model Ensembles (3-5km?) Experimental advanced assimilation techniques EnsDA 4D-var Hybrid

30 Hurricane Forecast Improvement Project (HFIP) Accelerate skill of numerical guidance and associated products –Intensity –Track Major foci –Ensemble systems –Data assimilation –Impact of high resolution –Physics improvements Established Teams Regional data assimilation Ensemble-based guidance Global and regional models and physics Ocean model and coupling Diagnostics Product generation

31 Hurricane Diagnostics Ongoing and continuous efforts to develop a system for comprehensive model diagnostics for hurricane forecasts for all resolutions (Vijay) Primary tasks include: –Evaluation of initial storm structure (analyzed) –Vortex evolution in the forecasts –Representation of large-scale flow in HWRF and GFDL compared to the GFS –Impact of boundary conditions, domain configurations –Impact of physics, ocean feedback, horizontal and vertical resolution –Evaluation of derived diagnostic products including energy, angular momentum and PV budgets Collaborative effort with Mark DeMaria Extend collaboration throughout community Model side-by-side Model side-by-side comparison comparison Standard diagnostics Standard diagnostics vert. shear vert. shear x-sections, etc. x-sections, etc. Compare w/obs Compare w/obs

32 Continued………//////t Diagnostics/Verifications workshop at NHC (hosted by Surgi, DeMaria, Pasch, Marks) May 4-6, 2009 Followed by HFIP Hi-Res workshop at NHC May 7-8, 2009

33 HWRF Porting to DTC Completed: HWRF Physics Vortex-following movable nested grid (WRF V3.01) Initial Vortex improvement techniques Post Processing (WPPV3, Vortex Tracker, atcfplot etc) In progress: Testing of HWRF physics ‏ Port HWRF ocean component: POM Documentation (scientific…technical) Joint EMC/NCAR WRF tutorial for hurricanes (Jan 2010)‏

34 Hurricane-Wave-Ocean-Surge-Inundation Coupled Models High resolution Coastal, Bay & Estuarine hydrodynamic model Atmosphere/oceanic Boundary Layer HYCOM 3D ocean circulation model WAVEWATCH III Spectral wave model NOAH LSM NOS land and coastal waters NCEP/ Environmental Modeling Center Atmosphere- Ocean-Wave-Land runoff fluxes wave fluxes wave spectra winds air temp. SST currents elevations currents 3D salinities temperatures other fluxes surge inundation radiative fluxes HWRF SYSTEM NMM hurricane atmosphere

35 THANK YOU for your Attention