The spatial distribution of severe convective storms and an analysis of their secular changes

Kurzfassung

Severe convective storms are responsible for billions of US dollars in damage each year around the world. They form an important part of the climate system by redistributing heat, moisture, and trace gases, as well as producing large quantities of precipitation. Reporting of severe convection varies from country to country, however, so that determining their distribution from the reports alone is difficult, at best. Evidence does exist that the intensity of some events, particularly tornadoes, follows similar distributions in different locations, making it possible to build statistical models of occurrence. Remotely-sensed observations provide some insight, but the relationship between the observable parameters and the actual events of interest limits the quality of the estimate. Another approach is to use observations of the larger-scale environments. As stated, the relationship between the observation and the event limits the estimate, but global coverage is possible. Time series of the favorable environments can also be developed from such data. In order to improve the estimates, the most pressing need is better observational data of events. Very few countries have formal systems for collection of severe thunderstorm reports. A new effort from a consortium of researchers in Europe to develop a continental-wide database offers the possibility of a significant improvement in data in that part of the world.