Storm Forecast
Valid: Tue 16 Jun 2020 06:00 to Wed 17 Jun 2020 06:00 UTC
Issued: Mon 15 Jun 2020 21:08
Forecaster: DAFIS

A level 2 was issued for Belarus and W Russia mainly for large hail and severe wind gusts.

A level 1 was issued for parts of Russia, E Latvia, E Esthonia, Belarus, Ukraine and Georgia for large hail, severe wind gusts and tornadoes.

A level 1 was issued for the Balkans and N Turkey mainly for large hail and excessive precipitation.

A level 1 was issued for N Italy mainly for large hail.

A level 1 was issued for Spain for large hail and severe wind gusts.

SYNOPSIS

Several cut-off lows affect the weather in Europe with 4 main vorticity maxima in the analysis maps. The highest vorticity values are found over the Baltic Sea but the lack of instability excludes the area from intense DMC activity and only a few non-severe storms may develop on Tue 16/06. Two more cold drops over the Balkans will provide lift to unstable air masses and several storms are expected. Another low-pressure system with a center over the Gulf of Biscay is surrounded by short-wave troughs, but the most important feature of this system is the interaction with a ridge over NW Africa and the development of jet stream over Spain. At the surface, an almost stationary front in Belarus and W Russia will be the triggering mechanism of several storms inside the level-2 area, along with diurnal heating.

DISCUSSION

.... Belarus and W Russia ....

Weakly capped and very unstable air masses along a surface boundary, will feed DMC on Tue 16/06. The level-2 area shows where the best conditions for organized DMC are expected. Even though DLS will remain below 10 m/s, comparable 0-3 km shear may lead to clustering of storms, where MLCAPE will exceed locally 2000 J/kg with steep lapse rates. The main threat will be large hail from isolated cells, but also severe wind gusts will pose a threat in the cold pools of MCSs.

.... Balkans and N Turkey ....

Under the 2 cold drops over the Balkans, locally steep lapse rates, weak storm motion and very moist PBL increase the probability for excessive precipitation events and large amounts of small hail from slow-moving storms. In N Turkey large hail cannot also be ruled out given the overlap of high CAPE and moderate DLS (15 m/s).

.... N Italy ....

Diurnally driven thunderstorms in the Alps will pose a threat for large hail due to steep lapse rates and high PWAT, even though the DLS will remain below 10 m/s.


.... Spain ....

Under the westerly jet stream, the DLS is expected to exceed 20 m/s. The overlap of strong DLS and up to 1000 J/kg MLCAPE will create a favorable environment for organized convection and even the development of supercells. The main threat will be large hail, especially close to the coasts.