Evaluation of ESTOFEX forecasts: Lightning forecasts

Over the past few years, an informal group of European meteorologists have forecast convective weather as part of the European Storm Forecast Experiment (ESTOFEX-http://estofex.org). The forecasts are intended to resemble the US NWS Storm Prediction Center convective outlooks, with a general thunder forecast and levels of severe thunderstorm (hail, wind gusts, or tornado) threat.

As part of a class project in a graduate course in Forecast Evaluation and Decision Analysis at the University of Oklahoma, ESTOFEX forecasts from 30 April 2006 to December 2007 were analyzed. There are over 500 forecasts considered.

Here, we report on the results of the general thunder forecasts. Cloud-to-ground lightning frequency on a 0.5x0.5 latitude/longitude grid, provided by the ESTOFEX group, form the observations. In general, the forecasts capture the distribution of observed lightning. The annual cycle of lightning and of the forecasts are obvious, as well as smaller differences between the five forecasters who participated during this time.

In a companion presentation, we report on the severe thunderstorm forecasts.