To provide the forecasters with tools for severe weather events monitoring with a suitable spatial and temporal resolution is very important. The NWCSAF project develops several products to make easier forecasters their nowcasting tasks.
The NWCSAF/MSG software package contains two products devoted to precipitation. Precipitating Clouds (PC) product assigns a probability of precipitation occurrence on each SEVIRI pixel. Convective Rainfall Rate (CRR) product estimates rain rates on convective, and stratiform associated to convection, events. The algorithms, on which those products are based, have currently two different approaches.
PC product takes advantage of surface temperatures and of those SEVIRI spectral features which have the highest correlation with precipitation, to construct a Precipitation Index (PI). According to this PI, which has been calibrated against rain gauges, a likelihood of precipitation occurrence is assigned to each SEVIRI pixel. CRR algorithm assigns rain rates to each pixel according to some SEVIRI channel information and some calibration functions, which have been calibrated using radar data. The influences of environmental and orographic effects on the precipitation distribution are taken into account through some corrections that use NWP data. Besides, two new products are included in the NWCSAF/MSG v2013 software package. These products also estimate the probability of precipitation and convective rainfall rates using a common approach, which takes advantage of cloud microphysical properties.
In a second talk, Natasa Strelec-Mahovic will present applications of the NWCSAF Precipitation Products.
Filed under Keywords:
Precipitation, clouds, rainfall rate, products