Storm Forecast
Valid: Wed 06 Feb 2008 06:00 to Thu 07 Feb 2008 06:00 UTC
Issued: Tue 05 Feb 2008 19:22
Forecaster: GATZEN

SYNOPSIS

High geopotential is present over north-eastern Europe. To the south-west, subtropical ridge amplifies over western Europe. A strong upper jet streak along the northern flank of the ridge is expected to move into central Europe in the wake of a propagating upper trough axis. Another short-wave trough is forecast to affect the Aegean Sea.

DISCUSSION

Germany

Intense trough is expected to propagate across Germany during the period. Its axis will move into Poland during the day. A strong upper jet curves around the trough's base in the morning hours, yielding strong DCVA from Benelux to central Germany.

At lower levels, a cold front is forecast to cross Germany in the morning hours. Warm air mass is forecast to be stable given relatively cool and dry boundary layer ahead of the cold front. Although strong QG forcing is forecast, chance for thunderstorms is expected to be very low. A narrow convective band may develop along the leading gust front associated with stormy winds, but embedded convection is not expected to contribute significantly.

In the wake of the front, convectively mixed maritime air mass will be present during the day just south of the surface low pressure center. Weak cold air advection is forecast in the range of this air mass, while models indicate some lift in the wake of the cold front. Limiting factor is weak low-level support given rather weak low-level convergence in the range of the trough axis. Maybe this will be better as shown by latest model output.

Expect that some convective cells will develop during the day, moderate vertical wind shear may be sufficient for some organized cells. 10 m/s 0-1 km vertical wind shear as well as some veering is forecast, and shallow mesocyclones are not ruled out. Although low-level buoyancy may be limited, and given weak low-level convergence, a few stronger cells are not excluded capable of producing some hail, wind gusts and tornadoes. Threat seems to be too low for a level 1, though. Later observations may warrant an upgrade in the morning hours.

Crete

Some instability is expected in the range of the trough axis, and weak vertical wind shear/locally good low-level buoyancy may support some waterspouts along the coasts of Crete.