1. NCEP/EMC Operational Hurricane Weather Research and Forecast (HWRF) Modeling System 1 Vijay Tallapragada JCSDA-HFIP Workshop on Satellite Data Assimilation for Hurricane Forecasting December 02, 2010

2. Outline Current operational HWRF system Evolution of HWRF FY2011 ongoing developments Collaborative efforts Future developments

3. Operational HWRF Modeling System Current operational HWRF –Regional-Scale Ocean-Atmosphere Coupled Modeling System specially designed to advance hurricane track and intensity forecasts. –Non-Hydrostatic system of equations formulated on a rotated latitude- longitude, Arakawa E-grid and a vertical, pressure hybrid (sigma-P) coordinate. –Based on WRF NMM V2.0 framework with movable, vortex following high- resolution nested grid –27 km outer domain, 9 km inner domain, 42 vertical levels Advanced vortex initialization and GSI/3DVAR data assimilation –Advanced vortex initialization and GSI/3DVAR data assimilation consisting of Vortex relocation, Storm size and intensity correction based on tcvitals, and combination of bogus (synthetic) vortex and six-hour cycling –Assimilation of satellite radiance datasets in the hurricane environment Coupled to Princeton Ocean Model (POM) in the Atlantic –Feature based initialization of cold wake, loop current, warm and cold core eddies Physical parameterizations designed for tropical environment –GFS/GFDL SAS Convection and PBL –GFDL Surface Physics, Radiation, Ferrier Microphysics 3

4. Evolution of HWRF Initial implementation in 2007 hurricane season –Model design and development of movable nested grid started in 2002 –Initial HWRF workshop at NSF in 2004 –28 different configurations tested individually (each with about 200 simulations) before initial implementation –Extensive 3-season (2004-2006) pre-implementation testing of HWRF for all storms in the Atlantic and Eastern Pacific basins Vortex initialization upgrades in 2008 –Address intensity bias for weaker systems, modifications to storm balance Infrastructure upgrade and transition to P6 in 2009 –Capability enhancements to allow coupling to HyCOM and Wave Watch-III –Script enhancements (identical scripts for NCO operations and EMC parallels) Physics and initialization upgrades in 2010 to improve the forecast skill. –New baseline version with several bug fixes –Modified surface physics formulation and use of Gravity Wave Drag parameterization –Addition of satellite radiance data assimilation in the hurricane environment –Focus on reducing intensity bias 4

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6. HWRF Atlantic Track Forecast Errors HWRF Atlantic Intensity Forecast Errors (less skillful at all times) Negative bias for HWRF Atlantic Intensity Forecasts Performance of the Operational HWRF for 2010 ATL hurricane season Rapid growth of intensity errors

7. HWRF E-Pac Track Forecast ErrorsHWRF E-Pac Intensity Forecast Errors (less skillful at all times) Negative bias for HWRF E-Pac Intensity Forecasts Performance of the Operational HWRF for 2010 EPAC hurricane season Rapid growth of intensity errors

8. Current HWRF activities/developments Major upgrade to the HWRF modeling system for 2011: –Establish a community repository of the operational HWRF and upgrade HWRF infrastructure to V3.2+ (collaboration with DTC) –Couple to HYCOM ocean model in the Atlantic –Improve vortex initialization for more realistic storm size and intensity corrections –Physics upgrades include testing of new GFS convection, modified PBL and modifications to treatment of horizontal diffusion –Simplified operational system with added flexibility and multi-platform compatibility Subversion based code management –HWRF-POM and HWRF-HYCOM baseline configurations for T&E –Synchronization of EMC and DTC repositories Product development –Generating simulated GOES WV and IR imagery and simulated radar reflectivity products starting in 2010 –Additional simulated microwave products in 2011/2012 –High-frequency output and additional derived variables for diagnostics –Enhancements to GrADS based HPLOT diagnostics and visualization software –New enhanced HWRF website for product display and navigation

9. WRF V3.2 WRF V3.1.1 WRF V3.1 WRF V3.0 WRF V2.2 WRF V2.1 WRF V2 05/2004 07/2009 04/2010 08/2005 12/2006 04/2008 04/2009 FY2011 Operational HWRF Configuration HWRF operational configuration (2011) Extensive Testing (pre implementation) WRF Repository (hosted by DTC) HWRF 2007 HWRF 2007 HWRF 2008 HWRF 2008 HWRF 2009 HWRF 2009 HWRF 2010 HWRF 2010 WRF V3.2+ 02/2011 upgrades 2011 upgrades 2011 Modified vortex initialization (storm size correction and balanced vortex) Coupling to HYCOM in the Atlantic New GFS Deep/Shallow Convection Modified PBL, Radiation, Microphysics Modified horizontal diffusion Modified vortex initialization (storm size correction and balanced vortex) Coupling to HYCOM in the Atlantic New GFS Deep/Shallow Convection Modified PBL, Radiation, Microphysics Modified horizontal diffusion Extensive Testing (individual upgrades) Regional Hurricane Model Development at EMC 9

10. HWRF produces too few strong storms Vortex Initialization Issues/Challenges Positive bias for weaker storms, negative for stronger storms (spinup/spindown) Broad initial vertical structure Insufficient vortex size correction

11. Size correction Intensity correction 6h fcst Modified vortex initialization procedure: Improved mass/wind balance & storm size correction, with a focus on reducing initial spinup/ spindown issues, and improve track/intensity forecast skill in the first 12-24 hrs

13. Forecast Time (9min) Maximum wind speed (kts) Time series of max. wind speed (Celia: 2010062218) 84kts becomes 55kts around the first 2hours 9kts drop at the first 9min

14. 34kts radii distribution observation (y-axis) vs HWRF forecast (x-axis) 06hr 96hr 48hr24hr 72hr 120hr

15. Band 3 Loop SimulatedBand 3 Loop Real 15

16. Ongoing Model development & collaborative efforts Further advancements to the HWRF modeling system (EMC & HRD) –third nest capability, advanced diagnostic capability (diapost), idealized simulations Code management and community support at DTC –Setup HWRFV3.2+ and provide support to the community through DTC –Development of R2O/O2R infrastructure and testing facility at DTC Data assimilation (EMC, HRD, CIRA) –Real-time test of the P3 TDR data flow from aircraft to NCO/TOC/AOC and assimilation using advanced GSI. –Ensemble data assimilation (MLEF, CIRA) and hybrid EnKF (HRD). HWRF Diagnostics (HFIP, EMC, NHC, FSU, CIRA, HRD, UMBC/UMD) –Identifying forecast errors from different components of model physics and dynamics –Hurricane model diagnostics, evaluation and verification –Develop a common and comprehensive diagnostics framework and tools to integrate model output with available observations for verification –Cloudtop datasets for storm scale diagnostics HWRF Physics (URI, GFDL, ESRL,HRD) –Surface fluxes, sea spray and wave coupling –Physics for high-resolution (convection, micro physics, PBL, LSM )

17. Hurricane-Wave-Ocean-Surge- Inundation Coupled Models High resolution Coastal, Bay & Estuarine hydrodynamic model* Atmosphere/oceanic Boundary Layer WAVEWATCH III* Spectral wave model 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 V2.0 Hurricane atmosphere 17 Princeton Ocean Model (POM) for Atlantic Region GFDL Slab Model NOAH LSM* *Future developments Upgrade to HWRF V3.2+ in FY2011 FY2011 Upgrade to HYCOM Ocean Model

18. HWRF Prioritized Activities for FY11 Comprehensive testing of HWRFV3.2 Focus on reducing intensity errors in the first 24 hrs of forecast Focus on improving track forecast skill Focus on improving intensity forecast skill Comprehensive HWRF model diagnostics Real-time parallels using high resolution triple nested HWRF (27/9/3) Real-time parallels using advanced GSI and hybrid-EnKF DA methods Continuous advancements to the HWRF modeling system

19. Advancing the HWRF System. 2011201220132014*2015* Resolution/ Infrastructure Triple nested HWRF (27/9/3 km) Increased vertical resolution, higher model top, upgrades to WRF infrastructure, NEMS/ESMF/NMM-B, community R2O efforts (HFIP) Physics Convection, PBL, Horizontal diffusion Shallow convection, Microphysics, Radiation, Surface Physics, Coupling to Waves and Land Surface, Physics for high-resolution DA/ Vortex Initialization Storm size correction, gradient balance Inner core (Doppler Radar, satellite) Hybrid-EnKF DA, advanced vortex relocation procedure, improved GSI Ocean HYCOM Coupling Improved ocean data assimilation, physics and resolution Waves One-way Wave CouplingTwo-way wave coupling, multi-grid surf zone physics, effects of sea spray Diagnostics and Product Development HWRF Ensembles, Coupling to Hydrological/ Surge/ Inundation models, diagnostics, product development Ongoing Work Potential 2011 upgrades Future developments *Potential Computer upgrade HWRFV3.2+

20. Thanks for your attention Questions?