Storm Forecast
Valid: Mon 12 Feb 2007 06:00 to Tue 13 Feb 2007 06:00 UTC
Issued: Sun 11 Feb 2007 22:18
Forecaster: GROENEMEIJER

SYNOPSIS

Monday... the primary feature of interest is a mid-level trough, initially extending SWward from a closed low over the Irish Sea, that moves into Europe. At the surface, the system is accompanied by a low-pressure system that moves eastward across Wales and England to the southern North Sea. An associated eastward-moving cold front should initially be near a line from western Belgium to southwestern France. The front is followed by moist, polar air. During the afternoon and evening a surface low is expected to develop over the Po Valley, that subsequently moves SEward over the Adriatic Sea.

DISCUSSION

SW England, W France, W Belgium...

Near the axis of the aforementioned mid-tropospheric trough cool air is present. The advance of the trough and the associated cool air will destabilize the environment across and around the level 1 area from the NW. A few 100s of J/kg are expected of which some may be located at low altitudes.

The combination with strong low-level shear on the southern flank of the deep surface cyclone will help convection to organize into lines and likely a couple of small supercells.
Some threat of tornadoes is expected across the entire level 1 area as well as marginally severe hail.

Strong and severe gusts are likely with any storm. Across the level 2 area, widespread severe gusts exceeding 25 m/s, and locally exceeding 32 m/s are expected on passage of convective squalls during the morning and early afternoon.

The convective threat is expected to diminish from the NW after passage of the mid-level trough in the early afternoon in the Channel region and in the late evening in southern France.