Forecasting Convective Downburst Potential Over The United States Great Plains

Abstract

A favorable environment for downbursts associated with deep convective storm systems that occur over the central and eastern continental United States includes strong static instability with large amounts of convective available potential energy and the presence of a mid-tropospheric layer of dry air. However, previous research has identified that over the central United States, especially in the Great Plains region, an environment between that favorable for wet and dry microbursts may exist during the convective season, resulting in the generation of hybrid type microbursts. Hybrid microbursts have been found to originate from deep convective storms that generate heavy precipitation, with sub-cloud evaporation of precipitation a significant factor in downdraft acceleration. Accordingly, a new GOES sounder derived product, the GOES Hybrid Microburst Index, is under development and is designed to assess the potential for convective downbursts that develop in an intermediate environment between a wet type, associated with heavy precipitation, and a dry type associated with convection in which very little to no precipitation is observed at the surface.