COPS and D-PHASE: QPF research in low-mountain regions on precipitation statistics, predictive skills of models, and high-impact weather events

Autor(en)

V. Wulfmeyer, H.-S. Bauer, A. Behrendt, T. Schwitalla, M. Dorninger, M. W. Rotach, M. Arpagaus

Abstrakt

This presentation gives an overview of results on QPF achieved during

the Convective and Orographically-induced Precipitation Study (COPS).

COPS is a WWRP Research and Development Project (RDP) dedicated to

improving QPF in low-mountain regions and for studying the

predictability of heavy precipitation events. In collaboration with the

WWRP Forecast Demonstration Project (FDP) D-PHASE, new high-quality

statistics of atmospheric variables such as precipitation during the

COPS observations period in summer 2007 in southwestern Germany/eastern

France have been derived. These data are essential for process studies

and model verification. For instance, the predictive skill of an

ensemble of state-of-the-art mesoscale models can be studied using

advanced skill scores. The results show strong remaining systematic

errors in the simulation of thermally-induced flows and the 3D

distribution of humidity. Case studies are particular useful for

investigating the key processes leading to heavy precipitation. A

high-impact precipitation event is investigated during IOP4b on June 20,

2007. During this case, strong interaction between large-scale

instabilities, mesoscale forcing, and low-level forcing caused by

thermally induced orographic flows was present. Late in the afternoon,

constructive interference between these forcing mechanisms took place

leading to the development of a mesoscale convective system with heavy

precipitation. This case is presented and discussed in detail at the

conference. Conclusions concerning the predictability of heavy

precipitation in low-mountain ranges are given. Suggestions are made for

the development of suitable ensemble forecast systems being able to

capture these events with acceptable QPF skill.

Organisation(en)

Institut für Meteorologie und Geophysik

Externe Organisation(en)

Federal Office of Meteorology and Climatology, MeteoSwiss, Universität Hohenheim, Leopold-Franzens-Universität Innsbruck

Publikationsdatum

09-2010

ÖFOS 2012

105206 Meteorologie

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