Storm Forecast
Valid: Wed 14 Dec 2011 06:00 to Thu 15 Dec 2011 06:00 UTC
Issued: Wed 14 Dec 2011 05:32
Forecaster: GATZEN

A level 1was issued for northern France, Benelux, and north-western Germany mainly for severe wind gusts.

SYNOPSIS

A long-wave trough is located over northwestern Europe. Embedded short-wave troughs will affect the North Sea region and Baltic Sea region during the day. The east Mediterranean is affected by an upper trough moving eastward.

DISCUSSION

Northern France, Benelux, north-western Germany

At the southern flank of a short-wave trough, a 40 m/s mid-level jet streak will propagate eastward, leading to rather strong lift and low-level convergence. Ahead of the trough axis, a tongue of rich low-level moisture spreads north-eastward, and mixing ratios of 6-7 g/kg are likely. Given neutral to slightly unstable lapse rates near the trough axis, some CAPE will likely develop. Latest observations already indicate showers and thunderstorms over north-western France.

Current scenario is that these showers and thunderstorms will spread into Germany on Wednesday. Severe wind gusts are forecast given 30 m/s low-level flow at 850 hPa. Additionally, tornadoes are not ruled out given 20 m/s 0-1km bulk shear and veering profiles at low levels.