Predicting East Coast Sea Breeze Initiated Convection Near Cape Canaveral, Florida.
AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
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Warm season thunderstorms represent a significant threat to daily operations at the United States Air Forces USAF Cape Canaveral Air Station CCAS and the National Aeronautics and Space Administrations NASA Kennedy Space Center KSC at Cape Canaveral, Florida. Many of these storms are initiated by the East Coast Sea Breeze ECSB which forms over the complex landsea interface around the Cape. Using data from the 1996-97 warm seasons, 184 sea breeze days were found in the Cape area. To isolate ECSB initiated convection, days were eliminated when outside forcing mechanisms other than the ECSB were indicated. This left 120 days on which only the ECSB affected the area. These days were categorized according to convective activity using NEXRAD reflectivity data and lightning data. The categories were days when no cells formed along the sea breeze front NCD, days when cells formed but no cloud-to-ground lightning CGL occurred CD, and days when cells formed and developed into thunderstorms with CGL LD. Our primary goal was to determine whether one could discriminate between a LD and a CD using 1000 and 1500 UTC radiosonde sounding parameters and surface area-averaged horizontal divergence. Each parameters ability to forecast a LD versus other days then was assessed. We also documented characteristics of undisturbed ECSB days. Seven stability parameters from the 1000 and 1500 UTC radiosonde soundings were calculated. Results showed that only the K Index at 1000 UTC statistically discriminated a LD from a CD. Relative Humidity RH and u and nu wind components from 1000 to 400 mb also were calculated for both sounding times. There were no statistically significant differences in RH between LD and CD at any pressure level for either sounding time. Likewise, the u wind component produced no statistically significant discrimination between the LD and CD categories.
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