Modifications to severe convective storm ingredients in the Alpine forelands for cases of strong and weak synoptic-scale flow

0510869 - ÚFA 2020 DE eng A - Abstrakt
Pucik, T. - Zacharov, Petr, jr. - Groenemeijer, P.
Modifications to severe convective storm ingredients in the Alpine forelands for cases of strong and weak synoptic-scale flow.
10th European Conference on Severe Storms (ECSS 2019). Münchene: European Severe Storms Laboratory e.V. (ESSL), 2019.
[European Conference on Severe Storms (ECSS) /10./. 04.11.2019-08.11.2019, Kraków]
Institucionální podpora: RVO:68378289
Klíčová slova: convective storm * supercell * synoptic-scale flow regimes * mountain meteolorogy
Obor OECD: Meteorology and atmospheric sciences
https://meetingorganizer.copernicus.org/ECSS2019/ECSS2019-206.pdf

Heavy precipitation is still one of the primary goals of numerical weather prediction. The most intensive events
occur very rare so it is hard to compare its predictability because of continuous changes in NWP models and
initial conditions. This paper aims to evaluate a detail forecasts of historical precipitation events characterized
by large value of weather extremity index (WEI). The forecasts are based on European reanalysis which provide
a spatially complete and coherent record of global atmospheric circulation. Unlike archived weather analyses
from operational forecasting systems, a reanalysis is produced with a single version of a data assimilation system,
including the forecast model used, and it is therefore not affected by changes in method. Furthermore, the reanalysis
often describes the atmospheric circulations better than contemporary NWP models.
The events are simulated using NWP model COSMO with 2.8km horizontal resolution over a domain of the Czech
Republic and its close neighbourhood. The reason of selected horizontal resolution is an appearance of convective
precipitation which is better described with detailed model with a deep convective parameterization switched off.
The initial and boundary conditions came from four different versions of European reanalysis – ERA Interim, ERA
40, ERA5 and ERA 20C. The 2.8 km predictions were nested directly in ERA reanalysis.
We selected 22 events from years 1979 to 2002 which is a range covered by all three chosen reanalysis. The
model starts at 00UTC and produce 24h precipitation total from 06-06UTC. The forecasts are verified against
precipitation totals from Czech precipitation network using grid to grid as well as spatial verification. The events
and the verification results are compared also with WEI values and synoptical conditions.
Trvalý link: http://hdl.handle.net/11104/0301238