1. Evaluating HWRF Forecasts of Tropical Cyclone Intensity and Structure in the North Atlantic Basin Dany Tran 11/2/2011

2. Focus Expand our understanding of the effects high resolution models and forecasts can have on tropical cyclone operations Improve depiction of structure and intensity Improve quality of 48-72hr forecasts relative to the featured locations

3. Objectives Evaluate wind field and rain band structures of cyclones before/after rapid intensification Evaluate accuracy of HWRF predicted feature locations and magnitude of landfalling Tropical cyclones Pin-point onset of threshold winds for impact areas especially for landfalling TC

4. Hurricane WRF (HWRF)….What is it The Weather Research and Forecast Modeling System for Hurricanes (HWRF) became operational in the year 2007. Constantly improved to increase the forecast skill for track, intensity and structure. Utilizes the WRF infrastructure. http://moe.met.fsu.edu/tcgengifs/

5. Approach Hurricane Earl (2010) will be investigated. – http://rammb.cira.colostate.edu/products/tc_realtime/arc hive_model_data.asp?product=hwrfprec&storm_identifier =al072010 http://rammb.cira.colostate.edu/products/tc_realtime/arc hive_model_data.asp?product=hwrfprec&storm_identifier =al072010 At least two cases from 2011 hurricane season.

6. Science How well cyclone circulation is represented in the 27, 9 and 3km domains How does the magnitude of low level inflow affect intensity changes in HWRF Effect of storm-size correction approach used in HWRF vortex initialization Can alternate model configurations improve forecasts of intensity Ocean coupling effect

7. Examples of post-landfall effects Hurricane Katrina (2005) – Significant damage as a post-landfall cyclone (slow-changing) Hurricane Fay (2008) – triggered extreme flooding (rapidly-changing)