Near-Real-Time Precipitation Analysis Over Europe

Summary

The UK Meteorological Office prepares hourly analyses of the extent and type of precipitation over a large part of Europe and the NE Atlantic. The analyses, which are available within about two hours of datum time, are primarily for use with a numerical dispersion and deposition model to predict the distribution of contamination in the event of a nuclear accident like that at Chernobyl in 1986.

Quality-controlled radar data from the Meteorological Office’s FRONTIERS system and radar data from other western European countries under the COST-73 project provide the most detailed information, but are supplemented by conventional surface observations, Meteosat imagery and products from NWP models. Analyses are generated at a resolution of about 5km within the COST-73 area and at the lower resolution of the Meteorological Office’s “fine mesh” regional NWP model beyond this, covering in all an area from 30°W to 40°E and 35°N to 70°N. It is planned to extend the area of high-resolution coverage as data from other national radar networks become available.

Combining the different observations and products into a coherent analysis is difficult because of their diverse characteristics. At present, where more than one type is available at a single location, they are selected according to an empirical preference order. Work continues on better ways to combine the data types, on using the observations to check and correct the NWP model predictions, and on the derivation of confidence values.