Assimilation of infrared Meteosat data into high-resolution NWP and nowcasting models

The SEVIRI instrument on the Meteosat Second Generation satellites provides infrared radiances operationally every 5 to 15 minutes with a pixel scale of 3km at the sub-satellite point. These observations are well-matched to high-resolution short-range forecasts models, such as those provided by the Met Office's operational 1.5km-resolution UKV 36 hour NWP forecast system and also its 1.5km nowcasting system currently under development. This presentation will discuss recent developments in the variational data assimilation system used for assimilating infrared SEVIRI radiances into the 1.5km models. The presentation will include analyses of the impact of model land surface skin temperature errors on clear-sky assimilation of infrared window-channel radiances and a discussion of integrated analyses of atmospheric and land-surface properties. Also discussed will be assimilation experiments using cloudy SEVIRI observations, and monitoring results comparing simulated and real SEVIRI observations.