Storm Forecast
Valid: Tue 28 May 2019 06:00 to Wed 29 May 2019 06:00 UTC
Issued: Mon 27 May 2019 22:20
Forecaster: DAFIS

A level 2 was issued for parts of Romania, Hungary, Slovakia, Poland and Ukraine for large hail, severe wind gusts and excessive precipitation.

A level 1 was issued for a large part of N Balkans and Eastern Europe mainly for large hail, severe wind gusts and tornadoes. Local flash floods are also possible.

A level 1 was issued for N Italy, Slovenia, Croatia, and Boznia and Herzegovina mainly for excessive convective precipitation.

SYNOPSIS

The cut-off low over S Italy is quickly moving northeast towards the Balkans, bringing a PVA over the warm and moist continental air masses. All thermodynamic parameters converge that DMC events should be expected in a large part of E Europe, as well as in N Italy. Another trough is approaching C Europe from the northwest, bringing instability also in W Europe, but storms should be low-topped and short-lived. Moreover, in Scandinavia local storms may form as NWP models show some hundreds of CAPE, but the entrainment of mid-level dry air will be the main inhibitor. In Turkey, most of the CAPE is strongly capped, but if any storm succeeds to develop, may become severe.


DISCUSSION

.... Romania, Hungary, Slovakia, Poland and Ukraine ....

All the available global and regional numerical models forecast a strong overlap of high instability and DLS. The approaching trough from the W-SW increase the mid-level wind flow and DLS is expected to exceed locally 20 m/s. MLCAPE is forecast to reach 2000 J/kg into this highly sheared environment and along with high PWAT suggest that storms will be able to create large hailstones. Well-organized convection will be also able to produce severe wind gusts and excessive precipitation. Thunderstorms that will develop in the late afternoon will be still active during the night in Romania and Ukraine.

.... Serbia, Poland, Romania, Hungary, Slovakia, Poland, Belarus, and Ukraine ....

A level-1 was issued for this part of Europe due to highly unstable air masses that lie below the mid-level strong flow. Steep mid-level lapse rates and 10-12 g/kg PBL mixing ratios will create some hundreds MLCAPE and diurnally driven thunderstorms will be able to produce hail, severe convective wind gusts and tornadoes. Tornadoes are mostly expected on the northern parts of the level-1 area, where low-level looped hodographs (high SREH) and strong LLS along with low LCLs increase the probability for tornadogenesis.

.... N Italy, Slovenia, Croatia, and Boznia and Herzegovina ....

Weakly sheared but unstable enough air masses to produce thunderstorms will lie in N Italy and NW Balkans. The advection of very moist low-level air masses from the SW and saturated vertical profiles show a high probability for excessive precipitation events.