Storm Forecast
Valid: Sat 02 Jul 2022 06:00 to Sun 03 Jul 2022 06:00 UTC
Issued: Fri 01 Jul 2022 22:37
Forecaster: PISTOTNIK

A level 1 and level 2 are issued for parts of Finland, Estonia, Latvia, Lithuania, Belarus and the Ukraine mainly for excessive convective precipitation and to a lesser degree for large hail and severe convective wind gusts.

A level 1 is issued for parts of Slovakia, Hungary, Romania, Bulgaria, Serbia, Bosnia-Herzegovina, Montenegro, Albania, North Macedonia and Greece for severe convective wind gusts and to a lesser degree for large hail and excessive convective precipitation.

SYNOPSIS

The dominant feature on the weather maps is a large cut-off low near the Faroe Islands the influences the NW sector of Europe. Embedded in the SW-erly flow at its forward flank, a positively tilted mid-level trough crosses S Scandinavia and Poland. Weaker cut-off lows are located over SW Russia and W of Portugal. These regions experience unsettled and temperate to slightly cooler-than-average weather conditions.
In contrast, high 500 hPa geopotential and very hot air covers the entire Mediterranean region and also extends to the Balkans, Belarus and Finland, through this blocking ridge weakens somewhat.

DISCUSSION

... belt from Finland to the W Ukraine ...

At the western fringe of the hot airmass, a cold front continues its slow eastward journey. Moisture accumulation ahead of it allows the build-up of CAPE mostly up to 1000 J/kg, locally more. By afternoon, scattered to widespread thunderstorms initiate at the front line, which features a pronounced convergence zone between prefrontal S-erly and postfrontal NW-erly winds and a strong temperature gradient.
The background flow at mid levels is almost perfectly front-parallel from S to N, therefore excessive rain is the main hazard. Strong pulse storms may also produce localized large hail and severe downbursts, though weak vertical wind shear (which only starts to increase behind the front) and the low probability of the storms to detach from the boundary are limiting factors. Convection mostly fades after sunset.

... east-central Europe to Balkans and Greece ...

Scattered afternoon storms are expected in the hot, deeply mixed airmass, in particular over mountains. Some severe, perhaps even dry downbursts are possible. In addition, lightning strikes may spark forest fires (though this hazard is not explicitly covered by our threat level scheme). The strongest pulse storms can also locally produce marginally large hail and heavy rain.