Forecast Update
Valid: Fri 28 Nov 2008 09:00 to Sat 29 Nov 2008 06:00 UTC
Issued: Thu 27 Nov 2008 09:35
Forecaster: TUSCHY/GROENEMEIJER

SYNOPSIS

Please refer to the outlook, issued at Thu 27 Nov 2008 18:01Z.

DISCUSSION

... W-coast of CNTRL and S-Italy ...

Latest high resolution visible image reveals discrete thunderstorms over the N-Tyrrhenian Sea moving to the NE. 00Z sounding of Cagliari sampled the interface of passing surface cold front and approaching dry slot very well. This environment with intense directional / speed shear and very low LCLs is very conducive for tornadic storms, combined with severe wind gusts (the station reported a wind gust of 31m/s around 00Z ). No further data available right now to confirm rotating cells, but the environment, painted by the latest GFS output, will be very favorable for storms to be tornadic. In addition, large hail and severe wind gusts are also possible with the more intense storms. Stable BL more inland should limit the severe risk, so only coastal areas were upgraded.

No major changes for the rest of the outlook beside excluding parts of the Bay of Biscay from the general thunderstorm area.