Real-Time Combination of Radar and Satellite Data for Very-Short-Period Precipitation Forecasting

Summary

Experience has shown that, even with the expanded UK weather radar network, use of satellite data to infer likely areas of precipitation beyond radar range enhances forecast accuracy. An investigation of the satellite rainfall estimation technique used currently, which involves correlating the radar data with Meteosat visible and/or infra-red data, is described and initial results presented. These illustrate the improvement resulting from careful registration of the satellite data and the relative accuracy of a bispectral technique compared to using visible or infra-red data alone. The method of optimising the rain/no rain boundary between satellite classes is discussed in detail and it is concluded that care must be taken in the choice of statistical measure which is maximised. The statistical evaluations are compared with subjective evaluations of the satellite precipitation fields.