May 29 - August 2
Verification of Low Level Vorticity in a High Resolution Forecast Model Using Radar Data
Kyle Howe, Jerry Brotzge, and Keith Brewster
Abstract:
The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) first integrative project (IP1) has provided researchers with radar data having high temporal and spatial resolution. These data are currently assimilated to produce short-term mesoscale forecasts of severe weather events. This case study considers a tornadic event that passed within range of the CASA network; multiple high-spatial and temporal resolution forecasts of these severe weather areas are examined. Five model runs were done, each using various combinations of NetRad (CASA) reflectivity, NEXRAD reflectivity, and Doppler radial velocity data. These high-resolution forecasts include areas of low-level vorticity, which were subsequently tracked and compared to verification data from the NEXRAD and CASA radar networks.
This case study provides a baseline for future research in this area as well as showing a direct and useful application of CASA radar data. Most of the models were skilled in predicting the location of these low-level rotation areas even two or three hours out. While it is hard to statistically verify these results, it does show that a high resolution forecast assimilating high-resolution radar data can do quite well in predicting severe weather.