Severe thunderstorm and tornado warnings in Europe

This study summarizes the current severe thunderstorm warning and forecast operations in different European National Hydro-Meteorological Services (NHMSs), and, in doing so, suggests ways for countries developing their own warning service to learn from experiences in other countries, as well as from the warning operations in the United States of America, the longest-lived severe thunderstorm warning operations in the world. This study is based on a questionnaire sent to 39 European NHMSs of which thirty-three (85%) responded. Currently, many European NHMSs are actively developing their severe thunderstorm forecast process and warning services with 26 (79%) of respondent countries issuing severe thunderstorm warnings and 8 (24%) issuing tornado warnings. Both warning criteria and methodologies used in the warning process vary from country to country. Lead-times range from 30 min to 96 h, indicating a range of different warning philosophies for each country. Major challenges toward improving the warning operations include obtaining observations of severe weather for real-time forecasting and post-event verification, educating forecasters, and having access to state-of-the-art forecaster workstations. An additional challenge is in communicating anticipated or ongoing severe thunderstorms, both internationally between NHMSs and nationally with media and emergency authorities.