Probabilistic high-resolution forecast of heavy precipitation over Central Europe

Abstract

Abstract. The limited-area ensemble prediction system COSMO-LEPS has been running operationally at ECMWF since November 2002. Five runs of the non-hydrostatic limited-area model Lokal Modell (LM) are available every day, nested on five selected members of three consecutive 12-h lagged ECMWF global ensembles. The limited-area ensemble forecasts range up to 120 h and LM-based probabilistic products are disseminated to several national weather services. COSMO-LEPS has been constructed in order to have a probabilistic system with high resolution, focussing the attention on extreme events in regions with complex orography. In this paper, the performance of COSMO-LEPS for a heavy precipitation event that affected Central Europe in August 2002 has been examined. At the 4-day forecast range, the probability maps indicate the possibility of the overcoming of high precipitation thresholds (up to 150 mm/24 h) over the region actually affected by the flood. Furthermore, one out of the five ensemble members predicts 4 days ahead a precipitation structure very similar to the observed one.

The COSMO-LEPS mesoscale ensemble system: validation of the methodology and verification

“…In the above mentioned references and in Marsigli et al (2004), it has been shown that, over a number of test cases and for several forecast ranges (48-120 h), LEPS (the early experimental system) and COSMO-LEPS (the real-time quasi-operational system) have shown better performance than EPS for the quantitative forecast of intense precipitation, as well as the geographical localisation of the regions most likely to be affected by the flood events. Then, as regards severe precipitation events, the impact the high-resolution within a probabilistic system seems to be positive.…”

Ensemble forecasts of a flood‐producing storm: comparison of the influence of model‐state perturbations and parameter modifications

“…Marsigli et al, 2004;Hohenegger et al, 2008;Leoncini et al, 2010;van Weverberg et al, 2010;Yussouf and Stensrud, 2011). The scope of the present study is to compare the uncertainties arising from two classes of forecast model uncertainty.…”

“…Indeed, despite the computational expense, experimentation with convective-scale ensembles is already well under way (e.g. Marsigli et al, 2004;Hohenegger et al, 2008;Leoncini et al, 2010) even while the operational use of a single forecast at these resolutions remains in its infancy. At the Met Office, for example, a convective-scale model has been run routinely since 2009 and a test system for ensembles at this scale is currently being built with the intention of trialling it during the spring of 2012.…”

Ensemble predictability of an isolated mountain thunderstorm in a high‐resolution model

“…The development of shortrange limited-area ensemble prediction systems with grid spacings of order 10 km has proved useful for quantitative precipitation forecasting (QPF) (e.g. Marsigli et al, 2004Marsigli et al, , 2005 and has therefore resulted in a movement towards convective-scale ensembles at O(1 km) grid spacing (e.g. Kong et al, 2006Kong et al, , 2007Hohenegger et al, 2008;Clark et al, 2010;Leoncini et al, 2010).…”