Forecast Update
Valid: Sat 03 Mar 2007 14:00 to Sun 04 Mar 2007 06:00 UTC
Issued: Sat 03 Mar 2007 14:09
Forecaster: TUSCHY

SYNOPSIS

Please refer to the outlook issued at Fri 02 Mar 2007 19:40 UTC !

DISCUSSION

...Germany...

Finally a few thunderstorms managed to evolve over S and SE Germany and a few severe wind gust and marginal hail reports were already recieved.

Decided to downgrade most parts of the level-1 area beside S-SE Germany, where constantly increasing 850hPa flow will pose an enhanced severe wind gust threat with each (thundery ) convection.
Very strong shear at lower levels will persist ( although veering will stay marginal ) and given pretty low LCLS and an isolated tornado report can't be excluded.
Latest soundings of Stuttgart and Nancy indicate pretty steep LL lapse rates, which indicates a favorable environment for an enhanced downward impulse of momentum of higher levels so there will persist an augmented severe wind gust threat with each convective segment during the next few hours !

...Parts of Austria, Croatia, Hungary, Bosnia and Herzegovina and Serbia...

An upgrade to a level-1 for most of those areas became necessary.

Latest radar images indicate scattered thunderstorms shifting towards the east over N-Austria.
An area of higher dewpoints (about 6-8°C ) can be found just south of Austria at 13Z and an increase of dewpoints of eastern Austria is expected during the next few hours.
Mid-levels will continue to cool down and surface temperatures locally already reached 10°C over E-Austria.
This environment will be favorable for storms to go on / re-develop with an attendant risk for an isolated tornado report. Main threat will be an enhanced severe wind gust threat, given rapidly increasing 850hPa flow.
Marginal hail, locally reaching severe limit will be possible, too ( especially if EL values continue to rise as latest model output indicated ).

Parts of Hungary were also included into a level-1 because of at least marginal instability release in a strongly sheared environment.
An isolated tornado report and a few severe wind gust reports will be possible.

Areas further towards the south / southwest will stay pretty warm at 850hPa with weaker LL lapse rates and conditions don't justify a level-1.