Storm Forecast
Valid: Tue 10 Nov 2015 06:00 to Wed 11 Nov 2015 06:00 UTC
Issued: Mon 09 Nov 2015 23:33
Forecaster: PISTOTNIK

A level 1 was issued for Belarus for severe convective wind gusts.

SYNOPSIS

A pronounced "high index" pattern is active over Europe. Low geopotential is centered over the Norwegian Sea and a subtropical high over Iberia. In-between, a strong frontal zone stretches from the British Isles across S Scandinavia into the Ukraine. It separates polar air with steep lapse rates but limited low-level moisture to the north from very moist but stably stratified subtropical air to the south. In general, this neat separation of the "ingredients" keeps the thunderstorm risk low despite the highly dynamic setup.
However, continuing warm air advection is dominant on the warm side of the frontal zone. In two areas discussed below, additional lift by embedded short-wave troughs may destabilize the atmosphere enough to create neutral and saturated profiles in the range of the broad, diffuse frontal zone. Buoyancy - either upright or slantwise - could allow the cloud shield to break up into convective bands under such conditions, though the confidence of electrified convection is limited.

DISCUSSION

... Belarus (06 to 12 UTC) ...

Kinematics are sufficient for organized convection with up to 15 m/s vertical wind shear and up to 300 m^2/s^2 storm-relative helicity, most of it concentrated in the lowest kilometer. Multicells or bowing line segments are not ruled out in the area where large-scale lift is maximized. A level 1 is issued for a risk of severe wind gusts.
Remnants of convection should soon disintegrate after 12 UTC while they spread into the N Ukraine.

... Netherlands across central Germany to the Czech border (15 to 00 UTC) ...

A plume of particularly moist air moves eastward (2m dewpoints between 12 and 14°C are observed in Ireland and England at Mon 22 UTC), but forecast soundings clearly suggest that it will detach from the ground when it spreads over the continent.
GFS and ECMWF agree on several small vorticity maxima aloft but not on their exact path yet. It appears reasonable that their lift may at least partly overlap with the very moist air. Isolated to scattered convection is possible, but their elevated nature should keep the effective vertical wind shear and hence the severe wind risk low. Nonetheless, a monitoring of the plume of highest 850 hPa dewpoints (>8°C) with respect to incipient convective signals is recommended.