Extended Forecast
Valid: Thu 10 Jul 2025 06:00 to Fri 11 Jul 2025 06:00 UTC
Issued: Tue 08 Jul 2025 22:36
Forecaster: TUSCHY

A level 2 was issued from the Ukraine into Belarus for large to very large hail, damaging gusts and heavy rain. A strong tornado event is possible.

A broad level 1 surrounds the level 2 for similar hazards but with lowered probabilities.


SYNOPSIS

An extensive cut-off still resides over E-CNTRL into E Europe and gets framed by positive height anomalies. Hence not much adjustment to the European wave pattern is forecast.

This extended outlook experiences substantial NWP differences (e.g. placement of the synoptic-scale fronts over E Europe), which results in a rather uncertain outlook. Hence only broad level areas were added for now. However current guidance points to an active severe weather day for most of Belarus into the Baltic States.

DISCUSSION

... Ukraine towards the Baltic States ...

An extensive LL vortex over the Ukraine shifts N/NW into Belarus. This vortex pushes a warm front towards the Baltic States and more into N Russia, whereas a cold front shifts E over the Ukraine.

Prefrontal airmass destabilization is forecast with rich BL moisture and modest mid-level lapse rates atop. A belt of 1000 to 1500 J/kg MUCAPE over the CNTRL Ukraine extends into Belarus, where peak values increase in excess of 2000 J/kg.

A belt of strong mid/upper-level flow affects the unstable airmass with DLS in excess of 20 m/s and similar values in the lowest 3 km. Scattered thunderstorms evolve beyond noon and grow into a mix of organized multicells and a few supercells, posing a threat of large hail, severe gusts and heavy rain.
Especially from N-CNTRL Ukraine into Belarus, the CAPE shear space supports severe bow echoes with swaths of damaging gusts, large hail and heavy rain. More discrete storms also pose a very large hail threat with numerous events forecast (hail diameter in excess of 5 cm). A strong tornado event is possible due to lowered LCL heights and curved hodographs. This activity spreads rapidly N/NW towards the Baltic States during the night, where elevated MUCAPE in excess of 1000 J/kg and strong shear still support organized convection with hail and heavy rain. There severe risk may increase in case the convection approaches earlier than currently forecast.

Further NE into Russia, diffuse forcing beneath a strengthening upper ridge should keep CI more on the isolated scale - mainly near the gradually northward lifting warm front. Any storm, which rides along the southern fringe of the warm front will move through 2000 to 4000 J/kg MUCAPE in 10-15 m/s DLS. Organized multicells and an isolated supercell bring all kind of hazards, including large hail and a tornado or two.