Storm Forecast
Valid: Sat 26 Sep 2015 06:00 to Sun 27 Sep 2015 06:00 UTC
Issued: Fri 25 Sep 2015 18:15
Forecaster: DAFIS
A level 1 was issued for parts of Belarus, Ukraine, Moldova and Romania mainly for excessive rain and large hail.
SYNOPSIS
A shortwave trough in the NW Balkans shifts NE during Saturday with a vorticity max over the level 1 area. High geopotentials in West Europe will result in fair weather conditions. On the contrary, a cyclonic vortex swirls in North Scandinavia where cold and wet conditions are forecast and in Southeast parts of the continent, E flow in low and mid levels will be supportive for mostly orographically enhanced convective phenomena.
DISCUSSION
.... Belarus, Ukraine, Moldova and Romania ....
A vorticity max moves over quite unstable air masses in E Europe and WAA from the SE results in steep mid level lapse rates. NWP models produce about 1 - 1.5 kJ/kg of MLCAPE with BL mixing ratio of 10-15g/kg. DLS and MLCAPE overlap over level 1 area but the highest DLS values (up to 30 m/s) are juxtaposed with CAPE values more than 300 J/kg, so the high risk of strong MCS occurrence is limited. PW is calculated up to 30mm by high resolution models and excessive rain or/and large hail is expected by the slow moving storms. The SREH 0-3km exceeds the 400mē/sē locally and will support the formation of multicells, especially during the night.
Other areas
Scatter CAPE signals under weakly sheared environments during Saturday will result in pulse storms, especially in E Spain and Greece where there is a limited risk of severe weather, except from mountain slopes. Moreover, waterspouts may form in Mediterranean coasts, where we have the overlap of weak low level wind field, 10 m/s or more of LLS and shallow convection.
