Experiments on the radar reflectivity data assimilation in the WRF-ARW model

Given are the results of numerical experiments on the radar reflectivity data assimilation in the nonhydrostatic WRF-ARW model. For this purpose, the procedure of three-dimensional variational data assimilation was used included as a separate block (WRF-3DVAR) in the WRF-ARW system. The experiments on the cyclic assimilation of radar information were carried out for ten days of summer of 2009. The data of six AKSOPRI complexes forming the Moscow ring of radar measurements were assimilated. The contribution of the radar reflectivity data assimilation to the quality of short-range precipitation forecasts was verified on the basis of the momentary and accumulated radar precipitation and total precipitation at the stations. It is obtained that the contribution of the radar reflectivity assimilation using the WRF-ARW algorithm to the precipitation forecast is close to neutral: the number of accurate forecasts increases by about 10%; however, the number of false alarms increases as well.