ESSL [Research - Waterspout climatology]

ESSL Research

Waterspout climatology, 2000-2007

This page will be updated annually, or when significant new data or results are available. The ESWD reporting criteria and thresholds are outlined in the ESWD data format description (ESSL Tech. Rep. 2006-01) available under "Publications".

Waterspout incidence in Europe

Waterspout incidence as a primary measure of hazard

This preliminary figure is based on ESWD reports of waterspouts (tornadoes over water). The 8yr-period covered is 2000-2007 for which a reasonably homogeneous pan-European data coverage has been achieved. The quantity depicted is incidence, i.e. number of ESWD reports per year per unit area. On a 1° × 1° latitude-longitude grid spacing, waterspout reports per year per 10 000 km² has been computed from 2000 to 2007. Due to the short, sub-climatological time period, the peak values in the graph are likely exaggerated compared to the "true" climatology. The relevant range of numbers (about 1 to 2 reports per year and per 10 000 km² is found frequently over European coastal waters, however.

Waterspout incidence as a primary measure of hazard
This preliminary figure is based on ESWD reports of waterspouts (tornadoes over water). The 8yr-period covered is 2000-2007 for which a reasonably homogeneous pan-European data coverage has been achieved. The quantity depicted is incidence, i.e. number of ESWD reports per year per unit area. On a 1° × 1° latitude-longitude grid spacing, waterspout reports per year per 10 000 km² has been computed from 2000 to 2007. Due to the short, sub-climatological time period, the peak values in the graph are likely exaggerated compared to the "true" climatology. The relevant range of numbers (about 1 to 2 reports per year and per 10 000 km² is found frequently over European coastal waters, however.

2000-2007 waterspout intensity distribution

Based on the data shown on the above map, the following intensity distribution over F-scale results:

F-scale	F-2	F-1	F0	F1	F2	F3	F4	F5	Sum	All reports	% rated	Avg. reports per year
Tornadoes over water	-	-	36	24	7	-	-	-	67	684	9.8%	86