Storm Forecast
Valid: Sat 02 May 2009 06:00 to Sun 03 May 2009 06:00 UTC
Issued: Fri 01 May 2009 22:23
Forecaster: DAHL

A level 1 was issued for northern Italy mainly for large hail and severe wind gusts.

SYNOPSIS

A rather weak upper-low system exists over the Balkans and the Black Sea, with one of the vort maxima moving from W Romania into the central Adriatic Sea region on Saturday. Farther north, a fairly strong branch of the polar front extends across the N Atlantic and Scandinavia, featuring a rather intense digging trough which is simulated to reach the North Sea late in the period. At low levels ... except for N-Atlantic low pressure regions, a rather weak and elongated SFC high-pressure area stretches from France into the Baltic States.

DISCUSSION

... N Italy ...

It seems that the only potential for organized severe storms exists over N Italy where DCVA-related ascent should aid in isolated thunderstorm development in the late afternoon hours. CAPE should be on the order of 1000 J/kg with DLS in the 15 to 20 m/s range. This should be sufficient for large hail and severe wind gusts to occur. However, currently it does not seem that widespread convection will evolve but confidence in at least isolated thunderstorms is sufficiently high for a LVL one threat.

Otherwise, generally weak shear and weak CAPE limit the tornado/hail/wind threat. Cells over the SW portions of Germany, extreme NE France and parts of Switzerland should move rather slowly and may lead to weak local flooding, but the environment seems to be too dry for a substantial heavy-rain threat, and a risk area is not deemed necessary at this time.