Storm Forecast
Valid: Mon 25 May 2020 06:00 to Tue 26 May 2020 06:00 UTC
Issued: Mon 25 May 2020 03:08
Forecaster: VAN DER VELDE

A level 2 (and 1) was issued across E Turkey, Armenia and Georgia mainly for large hail, severe wind gusts and tornadoes.

A level 1 was issued across SE Germany, S Czech Rep. and N Austria mainly for a chance of tornadoes.

SYNOPSIS

A large 500 hPa trough stretched across the Baltics, Poland and Romania with low upper temperatures creates a large area with modest instabiliy. A satellite low of this system ejects out of Turkey moving to S Russia, setting up a severe weather situation. A minor upper cold pool descends from Bay of Biscay into the Iberian Peninsula, where PV advection will likely interact with the unstable airmass to help storms last longer into the night.


DISCUSSION

...E Turkey, Armenia, Georgia...

A potent short-wave trough passing will provide large-scale lifting, with a few hundred J/kg CAPE indicated in models. The presence of over 300 m2/s2 0-3 km SREH and 25-30 m/s 0-3 km and 0-6 km shear vector magnitudes guarantees high potential for mesocyclonic updrafts and associated threats, large hail, severe wind gusts. Tornadoes are also not unlikely as 0-1 km shear is high with also low LCL heights.
The system continues norh of the Caucasus Mountains in the evening and night.

...SE Germany, N Austria, S Czech Rep...

As a shortwave passes north to south on the west flank of the upper low, modest CAPE forms north of the Alps. The northerly jet produces 0-6 km shear of 20-25 m/s and closer to ground a moderate 10 m/s 0-1 km shear is predicted. This suggests the chance of an isolated tornado occurrence.