Synoptic Environments Associated with the Training of Convective Cells

Abstract

Many studies have been done on synoptically forced systems and heavy rainfall, but little research has gone into the forecasting of training convective storms specifically in a synoptically forced environment. Training convective storms are recognized as the propagation of convective cells repeatedly over the same location. The research in this paper examines 38 separate synoptically forced convective extreme precipitation training (SCEPT) events to find trends and consistencies in their synoptic environments. Three separate cases were found in which a SCEPT event occurred: closed upper-level trough (CULL), upper-level trough (ULT), and 850-hPa trough?low (850TL). Each event occurred in areas of precipitable water greater than 36.42 mm (1.43 in.), near maximums of 850-hPa moisture convergence and 700-hPa upward vertical velocities, under the 850-hPa jet, and in the warm sector of a midlatitude cyclone. CULL and ULT events occurred in strongly forced synoptic environments where 500- and 300-hPa troughs were evident and generally positively tilted. Little upper-level forcing, above 700 hPa, was found in 850TL events.