0378033 - ÚFA 2013 RIV GB eng J - Journal Article
Sokol, Zbyněk - Zacharov, Petr, jr.
Nowcasting of precipitation by an NWP model using assimilation of extrapolated radar reflectivity.
Quarterly Journal of the Royal Meteorological Society. Roč. 138, č. 665 (2012), s. 1072-1082. ISSN 0035-9009. E-ISSN 1477-870X
Institutional support: RVO:68378289
Keywords : precipitation forecast * radar extrapolation
Subject RIV: DG - Athmosphere Sciences, Meteorology
Impact factor: 3.327, year: 2012
http://onlinelibrary.wiley.com/doi/10.1002/qj.970/abstract

Two methods for assimilating radar reflectivity into the COSMO numerical weather prediction (NWP) model were compared to precipitation forecasts. The first method assimilated observed radar reflectivity, and the second one assimilated observed and extrapolated radar reflectivity. The assimilation technique was based on the correction of the model's water vapour mixing ratio. The extrapolation was performed by the COTREC method and was 1 hour long. The model's horizontal resolution was 2.8 km. The comparison of methods was based on verification of the observed and forecast hourly precipitation. The comparison was performed for the 1st, 2nd and 3rd hours of each forecast. On the whole, 45 forecasts from nine days of convective precipitation were evaluated for each hour. The evaluation included subjective verification and the following objective skill scores: Fractions Skill Scores, SAL and a measure based on a categorical-probabilistic approach. The results confirmed that assimilation complemented by the extrapolated data improves the accuracy of precipitation forecasts. The improvement was obvious in a majority of the single forecasts studied, and it is confirmed by all evaluation techniques. COSMO forecasts that used the extrapolation showed reasonable competence in forecasting for the first and the second hours.
Permanent Link: http://hdl.handle.net/11104/0210022