U.S. Department of Commerce


Date of this Version



Published in NOAA Central Region, Applied Research Papers, Volume 27 (February 2003).


Forecasting the onset of severe convective weather across the High Plains can be difficult. Topography differences from one end of a county warning area to the other can differ up to 5,000 feet. These topographical differences are not well handled by numerical weather prediction models (NWP) primarily due to insufficient horizontal resolution. The inability of NWP to accurately represent topography impacts the model depiction of the location and depth of low level moisture, an important contributor to convective instability. Convective Available Potential Energy (CAPE ) is a measure of the amount of energy available for convection. The computation of CAPE is very sensitive to the amount of low level moisture (Bluestein 1993), so model forecasted CAPE can be unrepresentative in areas with large topographical differences. Given this deficiency in model resolution of topography, other parameters may serve as a better tool in forecasting severe convective weather across the High Plains. This paper establishes a baseline of various indices and parameters that can be used to analyze and forecast the threat for severe convective weather. For this study, 679 severe weather reports were collected and compared to fields from the 12 UT C Eta model 12 hour fore cast valid 00 UTC . These parameters, analyzed at are solution of 1° C, include K -index, Total- Totals, 700 mb temperatures, 700 mb dewpoints, and 500 mb temperatures, parameters often analyzed for forecasting thunderstorms. This paper addresses their potential in forecasting severe thunderstorms using a study similar to Bonner (Bonner et al. 1971).