A Forced Gravity Wave Model of Serf-Organizing Convection

Abstract

A two-dimensional, hydrostatic, nonrotating numerical model with a cumulus paramelerizafion is developed to study the early stages of mesozcale convective systems. Amplifying, forced gravity waves occur when peneirative downdrafts are present. Updraft heating by itself is unable to cause convective sysiems to intensify. Propagation speeds are in rough agreement with those observed in midlatitude mesoscale convective systems. The conditionalityof the convection and the horizontal advection of precipitation by the relative wind produce las between lifting and convection that are not found in conventional wave-CISK models. These lags slow the growth and reduce the propasation speeds of forced gravity waves.