Storm Forecast
Valid: Thu 21 Oct 2021 06:00 to Fri 22 Oct 2021 06:00 UTC
Issued: Thu 21 Oct 2021 07:13
Forecaster: GATZEN

A level 1 was issued across northern Central Europe and southern Baltic States for severe wind gusts.

A level 1 was issued across Balearic Islands and eastern Spain for extreme rainfall.

SYNOPSIS

A strong jet streak progresses across central Europe during the period. The associated intense trough indicates two main vort-maxima that start to lift into the Baltic Sea. Cold air advection sets in across most of western Europe in tne wake of an intense surface low pressure system moving across north Germany into the Baltic Sea. Farther south, a trough moves towards the Iberian Peninsula affecting the west Mediterranean late in the period.

DISCUSSION

Germany into Poland and Baltic States

Strong wind gusts will go on today in this region that are mostly driven by the strong surface pressure gradient and contribution by convective storms is rather low. Main convective activity is expected in the morning across the southern Baltic area due to an overlap of a very humid air mass with steep lapse rates and frontal lift. Given very strong low-level vertical wind shear, severe wind gusts are forecast with these storms, especially when linear segments develop. Tornadoes are not ruled out but potential is expected to decrease as LCL heights increase as well due to low-level mixing and moisture decrease.

Later in the period, showers and thunderstorms are forecast to spread from the North Sea into Germany. Due to marginal CAPE and also higher cloud bases, tornado potential is weak although low-level shear is still strong. Some severe wind gusts are the main thread with these storms.

Western Europe

Within the cold air advection regime to the west, showers are expected due to an intense trough axis, but overall potential for thunder is low due to rather dry low levels and a high equilibrium level temperature. Best potential exists across the Bay of Biscay due to higher moisture.

West Mediterranean

Ahead of the approaching trough, the progressing cold front intensifies across the west Mediterranean. Humid profiles and rather rich low-level moisture will pose a threat of excessive precipitation late in the period.