MONITORING AND PREDICTING HEAVY RAINFALLS ASSOCIATED WITH MESOSCALE CONVECTIVE SYSTEMS

Mesoscale Convective Systems (MCSs) sometimes produce extremely heavy rains over the central and eastern United States during the warm season. Indeed, many serious flash flood events are directly produced by MCSs, e.g., the most recent Johnstown flood disaster of 1975. During favorable, persistent synoptic patterns MCSs can contribute significantly to major river basin flooding, such as occurred during the summer of 1993.

The monitoring of MCS rainfall, e.g., primarily with radar and satellite remote sensing, is reviewed. The evolution of approaches for predicting MCS occurrence and precipitation amounts will be overviewed, beginning with almost purely subjective forecast techniques and covering the improvement during recent years of numerical models' ability to predict MCSs directly. Techniques that should lead to improved quantitative precipitation forecasts for MCSs in the future will also be considered. The emphasis will be upon real-time, operational monitoring and prediction techniques.