Forecasting thunderstorm initiation in north‐west Europe using thermodynamic indices, satellite and radar data

Abstract

A climatology of the occurrence of thunderstorms over north‐west Europe is described based upon an analysis of synoptic data, polar‐orbiting satellite infrared imagery and high‐resolution sferics data. The close relationship of thunderstorm initiation to orography, storm movements and the location of maximum storm intensity are illustrated. A number of instability indices derived from radiosonde data obtained from stations throughout north‐west Europe are objectively assessed both singularly and in combination. It is recommended that a forecast rule be used based upon taking the occurrence of a thunderstorm to be likely when any one of the indices indicates the occurrence of a thunderstorm. Additional methods of forecasting the location of thunderstorms using satellite data and techniques based upon the objective recognition of appropriate conceptual models are discussed. This leads to a proposed approach to a thunderstorm forecasting system to address the specific needs of operational hydrology.