Storm Forecast
Valid: Mon 26 Jun 2023 06:00 to Tue 27 Jun 2023 06:00 UTC
Issued: Sun 25 Jun 2023 23:24
Forecaster: GATZEN

A level 2 was issued across southern Russia for large to very large hail and severe wind gusts.

A level 1 was issued across northern Turkey to Kaukasus region for large hail and severe wind gusts.

A level 1 was issued across the southern Alps for large hail.

A level 1 was issued across western Iberia and Pyrenees for large hail and severe wind gusts.

SYNOPSIS

A broad trough is present across eastern Europe. A short-wave trough slowly moves east across south-eastern Europe, with 15 to 20 m/s mid-level jet streak affecting the Kaukasus region. Upstream, another trough follos from the Atlantic and breaks in response to high geopotential further north. An associated cold front will spread across western into Central Europe.

DISCUSSION

Kaukasus, Turkey

A moist and unstable air mass spreads westward along the northern slopes of the Kaukasus. Although mid-level lapse rates are only modest, rich low-level moisture allows for CAPE in the order of 1000 J/kg. Below the westerly jet, 15 m/s 0-3 km shear and 15+ 0-6 km shear develop. Lift will be quite strong and linear along a frontal boundary that moves east during the afternoon. Expect that a line of storms can develop with a more widespread wind threat. Additional storms forming along the slopes of the mountains will be capble of large or very large hail before merging to the linear system.

Across Turkey, CAPE is less, and forcing is rather weak. Expect some isolated storms that may cluster later on. Large hail is the primary threat together with severe gusts due inverted-v profiles.

Southern Alps

A capped air mass with plenty of low-level moisture and quite steep mid-level lapse rates will be affected by frontal lift late in the period as the cold front approaches. Next to diurnally driven storms over the mountains, some more storms are expected to develop that spread south-east during the night. Vertical wind shear will be limited, but expect some multicells and supercells capable of large hail.

Iberia

On Monday, some storms are expected to develop ahead of the approaching cold front. Steep low- to mid-level lapse rates allow for large DCAPE and storms are forecast to produce severe wind gusts. Additionally, some large CAPE in the hail growth layer supports a level 1 threat for large hail.