Predictability of Precipitation Patterns: An Operational Approach

Abstract

Predictability, defined as the ability to forecast precipitation over an area by Lagrangian persistence, is studied for 11 radar precipitation patterns. After a time ranging between 40 and 112 min, depending on individual cases, all forecast skill is lost. Attempts at relating this range of predictability to larger-scale meteorological parameters lead to positive results when the convective available potential energy is considered alone or in combination with wind shear energy. It appears from this study that the limited range of scales properly sampled by a single radar severely hampers the possibility of establishing a solid empirical relationship between mesoscale predictability and synoptic-scale meteorological parameters.