Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 25 Precipitation: Measurement, Climatology, Remote Sensing, and Modeling (EGU Session 2009) 2010 10.5194/adgeo-25-91-2010 http://www.adv-geosci.net/25/91/2010/ http://www.adv-geosci.net/25/91/2010/adgeo-25-91-2010.html http://www.adv-geosci.net/25/91/2010/adgeo-25-91-2010.pdf 91 95 2010-03-30 The effect of radar-based QPE on the Fractions Skill Score used at the QPF verification P. Zacharov D. Rezacova rez@ufa.cas.cz Institute for Atmospheric Physics, Prague, Czech Republic In this paper we show the influence of gauge adjustment technique, applied to radar-based rainfalls, on the results of QPF verification. The results were obtained for four convective events which produced heavy local rainfalls and caused local flash floods at the Czech territory. Numerical weather prediction model COSMO was run to obtain rainfall forecast and Fractions Skill Score was employed in the QPF verification. Three different radar-based quantitative precipitation estimates (QPE) were used for the verification and the verification results were compared. The QPE data sets consisted of: (a) raw radar-based rainfall values, (b) gauge corrected radar-based rainfalls with a simple domain-wide correction, and (c) radar-based rainfalls with a pixel related gauge adjustment. The results indicate small difference in area-related verification results and prove that the simple domain wide correction technique is sufficient for applying radar-based rainfalls as the verification data. Casaioli, M., Mariani, S., Accadia, C., Gabella, M., Michaelides, S., Speranza, A., and Tartaglione, N.: Radar adjusted data versus modelled precipitation: a case study over Cyprus, Adv. Geosci., 7, 85–90, 2006. Ebert, E. E.: Fuzzy verification of high resolution gridded forecasts: a review and proposed framework, Meteorol. Appl., 15, 51–64, 2008. Novak, P.: The Czech Hydrometeorological Institute's severe storm nowcasting system, Atmos. Res., 83, 450–457, 2007. Rezacova, D., Sokol, Z., and Pesice, P.: A radar-based verification of precipitation forecast for local convective storms. Atmos. Res., 83, 211–224, 2007. Rezacova, D., Zacharov, P., and Sokol, Z.: Uncertainty in the area-related QPF for heavy convective precipitation, Atmos. Res., 93, 238–246, 2009. Roberts N. M. and Lean H. W.: Scale-selective verification of rainfall accumulations from high-resolution forecasts of convective events, Mon. Weather. Rev., 136, 78–97, 2008. Sokol, Z.: The use of radar and gauge measurements to estimate areal precipitation for several Czech river basins, Stud. Geophys. Geod. 47, 587–604, 2003. Tartaglione, N., Mariani, S., Accadia, C., Casaioli, M., Gabella, M., Michaelides, S. C., and Speranza, A.: Sensitivity of forecast rainfall verification to a radar adjustment technique, Meteorol. Z., 15, 537–543, 2006. Zacharov, P., Šálek, M., and Novák, P.: Comparison of different methods for estimating precipitation based on radar and rain gauge measurements (in Czech with English summary), Meteorol. Zpravy., Meteorol. Bull., ISSN 0026-1173, 57, 157–167, 2004. Zacharov, P. and Rezacova, D.: Using the fractions skill score to assess the relationship between an ensemble QPF spread and skill, Atmos. Res., 94, 684–693, 2009.