ARPA - Agenzia Regionale per la Protezione dell'Ambiente - Italy
OSMER - Osservatorio Meteorologico Regionale - Italy
In the previos work "Evaluating the sounding instability with the Lifted Parcel Theory" we described a program which implemented the Lifted Parcel Theory in three different ways.
In this work we try to build a climatology of the sounding-derived instability indices based on 4330 different soundings, made in Udine (WMO code 16044) from april to september 1995-2000. Every 6 hours we associate a sounding with the presence of cloud-to-ground lightnings and also with a continuous variable, CALCA6h, built using lightning number, rain and wind gust, measured in the plain of our region.
For each of the about 30 indices we studied the skill score for forecasting the presence of thunderstorms and the linear cross correlation for forecasting the thunderstorm "intensity". We also introduce the use of some relatively new indices: the Maximum Buoyancy, the Cloud Precipitable Water and the standard deviation of the sounding vertical velocity. Finally we discuss which indices and which of the three methods are the best in our region for forecasting convective events.