Storm Forecast
Valid: Mon 11 Jun 2007 06:00 to Tue 12 Jun 2007 06:00 UTC
Issued: Sun 10 Jun 2007 22:15
Forecaster: GROENEMEIJER

SYNOPSIS

Monday morning at 06:00 UTC, the flow across Europe is still blocked as an elongated trough from S Greenland to the North Sea to the central Mediterranean dominates the weather maps. Two small mid/upper lows are embedded within the ridge. One should be located over E Scotland, the other over NE France on Monday morning.The three major lows flanking the ridge are located near Svalbard, the Bosporus and and 1000 km WNW of Cape Finisterre respectively.

DISCUSSION

A relatively moist and rather unstable air-mass is expected to remain present over much of the European mainland. 1) Diurnally driven destabilization, 2) weak ascent in the vicinity of subtle upper-level vorticity perturbations and 3) outflow boundaries from older convective activity will control the convective evolution there.
A major feature is the MCS that developed over southern France Sunday afternoon and evening. Ahead of this feature, over eastern France rather widespread convection can be expected to develop on Monday.
CAPE values in excess of 1000 J/kg are possible in some places, but significant shear is not forecast so that storm will be poorly organized. Hence the coverage of severe events is not expected to be high enough to warrant a threat level.

S Belarus, Ukraine...

A surface trough initially extending from N Belarus to S-central Poland is expected to move slowly SEward. It form the boundary between rather moist air ahead of it and much drier air behind it. Moderate NWly mid-level flow of about 15 m/s at 500 hPa and weak winds near the surface should create sufficient shear for the organization of convection that develops along the trough into a MCS. Some hail exceeding 2 cm diameter around and marginally severe wind gusts are possible with this activity so that a level 1 has been issued.