Storm Forecast
Valid: Thu 02 Jun 2022 06:00 to Fri 03 Jun 2022 06:00 UTC
Issued: Wed 01 Jun 2022 22:53
Forecaster: GATZEN

A level 2 was issued across southern central France for large hail and severe wind gusts.

A level 1 was issued across southern France, Pyrenees, and southern Alps for large hail, severe wind gusts, and heavy rain.

A level 1 was issued across north-east Urkaine and western Russia for heavy rain.

A level 1 was issued across southern Finland and north-western Russia for severe wind gusts and tornadoes.

SYNOPSIS

A deep mid-level vortex is present across Scandinavia that will lift slowly during the period. A negatively-tilted short-wave trough progresses ahead of the vortex and enters Finland, supporting cyclogenesis. At the southern periphery of this low, a frontal boundary is located across eastern Europe.

During the period, heights start to increase over much of western Europe in response to warm air advection ahead of an Atlantic trough. The tightening frontal zone is associated with the development of strong mid-level westerly flow and increasing vertical wind shear.

DISCUSSION

Southern central France

Warm air advection affects Spain and France that increases during the period. A Plume of elevated steep lapse rates will spread north where is overlaps to a moist air mass that becomes unstable in response to diurnal heating. On th warm flank of the frontal boundary, supported by topographic lifting, convection initiation becomes more likely during the afternoon and evening.

Storms that form are expected to organize in strong deep layer vertical wind shear. Straight hodographs support splitting storms capable of large or very large hail as well as severe wind gusts. Additionally, strong 0-3 km vertical wind shear and ongoing frontal lift can result in clusters of storms capable of severe wind gusts. After sunset, convective activity is expected to go on, but low-level stabilization will result in a limited severe potential especially with regard to severe wind gusts.

Southern Alps

The Alps are affected by a frontal boundary with rich low-level moisture. Diurnal heating is expected to yield weak MLCAPE and storms are expected to develop over the mountains. Strong deep-layer vertical wind shear is in place, and some splitting storms are forecast, capable of large hail and severe wind gusts. The high movement speed reduces the risk of heavy rain.

Eastern Europe

A frontal boundary will be the focus of convective development as a short-wave trough progresses north-east, and widespread storms are forecast. These are capable of local (marginally severe) hail, severe wind gusts, and heavy rain. The highlighted level 1 indicates the highest potential of heavy precipitation due to a maximum of low-level moisture in weak flow.

Finland, north-west Russia

The cold front of an intensifying low moves northward. A moist and slightly unstable air mass is forecast ahead of the cold front, and a frontal rain band is expected with some pre-frontal storms possible. Strong low-level vertical wind shear is present along with low cloud bases, and storms that form will be capable of severe wind gusts and tornadoes.