Impacts of Observational Data Assimilation on Operational Forecasts

COSMO model is a non-hydrostatic limited-area model mainly used by National Meteorological Services for operational applications. In the present study operational forecasts over Switzerland for the entire year 2013 have been compared with forecasts in which no observational data are used for the assimilation. The numerical weather prediction model COSMO is applied at 2.2 horizontal resolution and variables used for everyday operational forecast, such as 2 m temperature, total precipitation and total cloud coverage are evaluated against observations in both cases. A small improvement is evident in 2 m temperature while for precipitation the use of observational data slightly affects POD during dry seasons.