Evaluation of the QPF of convective flash flood rainfalls over the Czech territory in 2009

0395311 - ÚFA 2014 RIV NL eng J - Journal Article
Zacharov, Petr, jr. - Řezáčová, Daniela - Brožková, R.
Evaluation of the QPF of convective flash flood rainfalls over the Czech territory in 2009.
Atmospheric Research. Roč. 131, Sep (2013), s. 95-107. ISSN 0169-8095. E-ISSN 1873-2895
R&D Projects: GA MŠMT LD11044; GA ČR(CZ) GPP209/12/P701
Institutional support: RVO:68378289
Keywords : Convective precipitation * Quantitative precipitation forecast * Forecast verification * Fractions skill score * SAL verification
Subject RIV: DG - Athmosphere Sciences, Meteorology
Impact factor: 2.421, year: 2013
http://www.sciencedirect.com/science/article/pii/S0169809513000914#

In this paper, quantitative precipitation forecasts are evaluated using several verification techniques and analysis of the results from these techniques. The forecasts were produced by two limited-area NWP models: the ALADIN-CZ model operated by the Czech Hydro-Meteorological Institute and the COSMO model operated by the German Weather Service. Each model was run using two horizontal resolutions over the domain covering the Czech Republic. The ALADIN-CZ model outputs were obtained using resolutions of approximately 9 km and 4.7 km, and the COSMO model outputs were obtained using resolutions of approximately 7 km and 2.8 km. A series of 3-h rainfalls was verified using traditional and spatial verification techniques, and the results from these analyses were compared. The verification was performed using traditional verification scores based on a contingency table, spatial verification by the fractions skill score and the SAL technique. The FSS represents a fuzzy verification technique and compares the fractional coverage of precipitation grids over a threshold in spatial windows around the observations and forecasts. The SAL is a spatial object-oriented verification technique used to evaluate the structure, amplitude, and location of a precipitation field. The quality of QPF depends strongly on the scale of convective precipitation, and all models provide good forecast quality for extended rainfall systems. The opposite is true for the local and more or less chaotic convection during the final part of the time period. The FSS indicates how the results depend on the threshold and scale of precipitation. The COSMO 2.8 model is able to determine the largest local rainfall values, but models with lower resolution, such as the ALADIN 9 km and COSMO 7 km, provide better results for lower thresholds and larger scales. The use of more verification techniques is suitable for a modeller-oriented evaluation of different aspects of forecast quality.
Permanent Link: http://hdl.handle.net/11104/0223381