Storm Forecast
Valid: Sat 14 Apr 2007 08:00 to Sun 15 Apr 2007 06:00 UTC
Issued: Sat 14 Apr 2007 08:24
Forecaster: DAHL

SYNOPSIS

High-over-low block persists over Europe ... with the upper cut-off low expected to be located over the SW Mediterranean and the N Maghreb States by Saturday morning, but to to discontinue its eastward progress and undergo substantial weakening in the course of Saturday. Weakening SFC low pressure system over the W Mediterranean will accompany the upper feature, while large SFC high persists over central and NE parts of Europe. Warm and partly weakly unstable air masses are advected into W Europe at the W periphery of the SFC high.


DISCUSSION

... Tyrrhenian Sea ... S Italy ...

Convective potential should persist E of the SW Mediterranean upper low which exhibits several vort maxima at its periphery. One such vort max is expected to affect the Tyrrhenian Sea and S Italy early in the period ... during the day, the large-scale forcing for ascent should generally weaken.  Since CAPE and deep-layer shear should be quite weak, organized severe threat appears to be rather low. Low-level wind field as well as low-level moisture profiles currently do not seem to reveal severe potential, either.

... France ...

Isolated afternoon TSTMS could develop over France ...though meager LL moisture should make it difficult for positive CAPE to develop.  Local moisture accumulation near mesoscale boundaries could support an isolated TSTM or two, but allover coverage should remain rather weak - if storms form at all.  Given vanishing CAPE and weak vertical shear, severe evolution appears to be unlikely at the moment.