1. Requirement for North America THORPEX Science Plan Dr. Louis Uccellini Director NWS/National Centers for Environmental Prediction North American Science Steering Committee Meeting University of Maryland, August 14-15 2003 USWRP

2. THORPEX Program Structure THORPEX ICSC THORPEX IPO THORPEX ISSC WWRP /AREP NASSC ASCEUSSC THORPEX CAS S H USWRP IWG NASA NSF NOAA NAVYOthers WGNE /WCRP Commission on Atmospheric Science (CAS) International Core Steering Committee (ICSC) International Program Office (IPO) International Science Steering Committee (ISSC) North American Science Steering Committee (NASSC) United States Weather Research Program (USWRP) World Meteorological Organization CANADA

3. USWRP Foci Optimal Mix THORPEX WRF/DTC/OTC JCSDA/SPoRT Hurricane at Landfall CAMEX CBLAST JHT Extended/QPF Forecasts Warm Season (IHOP) Cool Season Hydromet Test Bed IPO Lead Scientist Societal Impacts Science Processes Coordination Future Foci Surface Transportation Air Quality IPO and USWRP Program Requirements & Support Primary USWRP Science Foci USWRP

5. North American Ensemble Forecast System Joint Canadian-U.S. Ensemble Forecast System –Currently in Planning Stage Research to Operations –Merge two ensembles with  60 members –Produce “seamless” forecast out to 15 days for NA Accelerate improvements in probabalistic forecasting

6. North American Ensemble Forecast System (Project Elements) Exchange data Statistically post-process both sets of ensembles –Bias removal –Forecast anomalies (downscaling) Merge ensembles – includes lag averaging –Evaluate added value Develop new products CORE PROJECT Potential Applications – Targeted observations – Improved data assimilation

7. “Requirements” for NA THORPEX Science Plan Clear need for NA science plan within organizational construct of the THORPEX program Basis for participation of U.S. science/research agencies (through USWRP-IWG) Key to defining research basis for improving 15 day operational forecasting based on NAEFS USWRP