Forecast Update
Valid: Fri 26 Feb 2010 11:00 to Sat 27 Feb 2010 06:00 UTC
Issued: Fri 26 Feb 2010 10:50
Forecaster: TUSCHY

A level 1 was issued for parts of Italy mainly for large hail.

A level 1 was issued for the Adriatic Sea mainly for severe wind gusts, large hail and an isolated tornado.

A level 1 was issued for the W-English Channel mainly for severe wind gusts and an isolated tornado.

SYNOPSIS

Please refer to the main outlook, issued at Thu 25 Feb 2010 18:57 UTC.


DISCUSSION

... N-Italy ...

Parts of N-Italy were upgraded as surface cyclogenesis starts somewhat more to the south than anticipated. Thunderstorms may pose a large hail threat, as DLS is supportive for organized updrafts. Overall scenario remains the same to what was described in the main outlook and thunderstorms decrease from NW to SE during the daytime hours.

... E-France and SW-Germany ...

The level-1 will be downgraded as scheduled. The cold front had some convective elements over extreme E-France and NW-Switzerland just at the start of the forecast period with strong gusts, but the baroclinic zone rapidly decayed thereafter. Broad field of wrap-around moisture now enters the area from central France, but conditions for a more substantial development are too marginal for extending the level area.

... W-English Channel, 21 UTC onwards...

We finally decided to issue a level 1 for that region due to enhanced probabilities for deep convection. Approaching trough sustains its positive tilt, so rather moist LL air is able to move northeastwards beneath cold mid-levels. Enhanced convection is forecast with isolated thunderstorms possible. The main risk will be severe wind gusts with winds at 850hPa increasing to 20-25m/s. An isolated tornado may be possible along the SW coast of the UK, as LL directional shear increases somewhat.