Storm Forecast
Valid: Mon 18 Jun 2007 06:00 to Tue 19 Jun 2007 06:00 UTC
Issued: Sun 17 Jun 2007 22:12
Forecaster: GROENEMEIJER

SYNOPSIS

A moderately strong WSWly mid-level flow is located over much of western and central Europe north of a broad ridge. The flow has two speed maxima: one travelling eastward over northern France into Germany and another, stronger one, over the northern Mediterranean, just south of the Alps. A minor shortwave trough over northwestern France is embedded in the flow and moves eastward.
Over the E North Atlantic a rather intense cut-off low moves slowly eastward towards the Bay of Biscay. Another low is located over northern Scandinavia while a large trough stretches Sward from the eastern Ukraine to the Red Sea.

DISCUSSION

France, SE Benelux, W Germany...

Ahead of the aformentioned minor shortwave trough, initially over NW France, upward vertical motions are expected to both increase lapse rates somewhat and induce surface convergence, so that the formation of scattered convective storms is likely as diurnal cycle destabilizes the lower troposphere in the early afternoon. Deep layer shear on the order of 15-20 m/s, locally higher, and expected MLCAPEs of 500-1000 J/kg suggest that a few large hail events are possible and a level 1 is marginally warranted. The storms should decrease in coverage during the evening.