Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 13 9 2009 10.5194/hess-13-1649-2009 http://www.hydrol-earth-syst-sci.net/13/1649/2009/ http://www.hydrol-earth-syst-sci.net/13/1649/2009/hess-13-1649-2009.html http://www.hydrol-earth-syst-sci.net/13/1649/2009/hess-13-1649-2009.pdf 1649 1658 2009-09-16 Dynamically vs. empirically downscaled medium-range precipitation forecasts G. Bürger gbuerger@uni-potsdam.de Universität Potsdam, Institut für Geoökologie, Potsdam, Germany currently at: Pacific Climate Impacts Consortium, Victoria, Canada For three small, mountainous catchments in Germany two medium-range forecast systems are compared that predict precipitation for up to 5 days in advance. One system is composed of the global German weather service (DWD) model, GME, which is dynamically downscaled using the COSMO-EU regional model. The other system is an empirical (expanded) downscaling of the ECMWF model IFS. Forecasts are verified against multi-year daily observations, by applying standard skill scores to events of specified intensity. All event classes are skillfully predicted by the empirical system for up to five days lead time. For the available prediction range of one to two days it is superior to the dynamical system. Bürger,~G.: Expanded downscaling for generating local weather scenarios, Clim. Res., 7, 111–128, 1996. Bürger,~G.: Selected precipitation scenarios across Europe, J. Hydrol., 262(1–4), 99–110, 2002. Bürger,~G., Fast,~I., and Cubasch,~U.: Climate reconstruction by regression-32 variations on a~theme, Tellus A, 58(1), 227–235, 2006. Bürger,~G., Reusser,~D., and Kneis,~D.: Early flood warnings from empirical (expanded) downscaling of the full Ensemble Prediction System, Water Resour. Res., doi:10.1029/2009WR007779, in press, 2009. Baldauf,~M. and Schulz,~J P.: Prognostic precipitation in the Lokal-Modell (LM) of DWD, COSMO Newsletter, 4, 177–180, 2004. Bartholmes,~J C., Thielen,~J., Ramos,~M H., and Gentilini,~S.: The european flood alert system EFAS – Part 2: Statistical skill assessment of probabilistic and deterministic operational forecasts, Hydrol. Earth Syst. Sci., 13, 141–153, 2009. Charba,~J P., Reynolds,~D W., McDonald,~B E., and Carter,~G M.: Comparative verification of recent quantitative precipitation forecasts in the National Weather Service: A~simple approach for scoring forecast accuracy, Weather Forecast., 18(2), 161–183, 2003. Clark,~M P. and Hay,~L E.: Use of medium-range numerical weather prediction model output to produce forecasts of streamflow, J. Hydrometeorol., 5(1), 15–32, 2004. Damrath,~U., Doms,~G., Frühwald,~D., Heise,~E., Richter,~B., and Steppeler,~J.: Operational quantitative precipitation forecasting at the German Weather Service, J. Hydrol., 239(1–4), 260–285, 2000. Ebert,~E E., Damrath,~U., Wergen,~W., and Baldwin,~M E.: The WGNE assessment of short-term quantitative precipitation forecasts, Bull. Am. Meteorol. Soc., 84(4), 481–492, 2003. Elementi, M., Marsigli, C., and Paccagnella, T.: High resolution forecast of heavy precipitation with Lokal Modell: analysis of two case studies in the Alpine area, Nat. Hazards Earth Syst. Sci., 5, 593–602, 2005. Hamill,~T M., Whitaker,~J S., and Mullen,~S L.: Reforecasts: An Important Dataset for Improving Weather Predictions, Bull. Am. Meteorol. Soc., 87(1), 33–46, 2006. Ledermann,~W., Churchhouse,~R F., and Vajda,~S.: Handbook of Applicable Mathematics: Statistics, John Wiley & Sons, 1984. Liu,~X., Coulibaly,~P., and Evora,~N.: Comparison of data-driven methods for downscaling ensemble weather forecasts, Hydrol. Earth Syst. Sci., 12, 615–624, 2008. Majewski,~D., Liermann,~D., Prohl,~P., Ritter,~B., Buchhold,~M., Hanisch,~T., Paul,~G., Wergen,~W., and Baumgardner,~J.: The operational global icosahedral–hexagonal gridpoint model GME: Description and high-resolution tests, Month. Weath. Rev., 130(2), 319–338, 2002. McBride,~J L. and Ebert,~E E.: Verification of quantitative precipitation forecasts from operational numerical weather prediction models over Australia, Weather Forecast., 15(1), 103–121, 2000. Menzel,~L., Thieken,~A H., Schwandt,~D., and Bürger,~G.: Impact of climate change on the regional hydrology – scenario-based modelling studies in the German Rhine catchment, Nat. Haz., 38(1), 45–61, 2006. Richard,~E., Buzzi,~A., and Zangl,~G.: Quantitative precipitation forecasting in the Alps: The advances achieved by the Mesoscale Alpine Programme, Q. J. R. Meteorol. Soc., 133(625), 831–846, 2007. Thompson,~J C.: On the operational deficiencies in categorical weather forecasts, Bull. Amer. Meteor. Soc, 33, 223–226, 1952. White,~B G., Paegle,~J., Steenburgh,~W J., Horel,~J D., Swanson,~R T., Cook,~L K., Onton,~D J., and Miles,~J G.: Short-term forecast validation of six models, Weather Forecast., 14(1), 84–108, 1999. White,~P W.: IFS Documentation, ECMWF, Reading, 2002. Wilks,~D S.: Statistical methods in the atmospheric sciences, Academic Press, San Diego, 1995.