Preliminary Results of the AEROMET Project on the Assimilation of the Rain-Rate from Satellite Observations

The regions close to the sea are often hit by meteorological systems that generate over the sea and then are advected towards the land. These systems impact the activities over the sea and is it important to predict their occurrence for the safety of the people as well as for the best prediction of ship-routes. The lower number of meteorological observations over the sea compared to the land and the absence of the orographic triggering mechanism, makes prediction of these storms difficult. Satellite observations are very important in this framework because they provide data over both land and sea that can help the prediction of convective storms. The AEROMET project (AEROspatial data assimilation for METeorological weather prediction) aims to assimilate the rain-rate estimated from satellite observations into the Numerical Weather Prediction (NWP) Weather Research and Forecasting (WRF) model to improve the prediction of convective meteorological systems, especially those originating over the sea. The method to assimilate the rain-rate is straightforward: given the best estimate of the rain-rate, it is assimilated in the model through 3D-Var with a simple cloud model. Two examples, occurred on 10 December 2021 and on 15 February 2022, show the feasibility of the method, nevertheless many cases must be studied to quantify the impact of the assimilation of satellite observed rain-rate on the precipitation forecast.