Storm Forecast
Valid: Fri 04 Jul 2008 06:00 to Sat 05 Jul 2008 06:00 UTC
Issued: Thu 03 Jul 2008 18:22
Forecaster: TUSCHY

SYNOPSIS

A strong surface depression just west / southwest of UK and Ireland will slow down as surface and upper circulation become vertically stacked and this feature will wobble around during the remainder of the forecast period. A cold - core upper - level low over Latvia / Lithuania moves southwards while weakening. Very warm and stable conditions prevail over the Mediterranean area.

DISCUSSION

... NE Poland, parts of Lithuania and western Belarus ...

A southward moving cold - core upper - level low pressure area atop moist and warm low levels results in modest instability release with MLCAPE values between 400 and 700 J/kg. Cold mid - and upper - level atmosphere and hence steep mid - level lapse rates and DLS in the order of 15 - 20 m/s support large hail with stronger storms. Degree of instability release should limit the chance for very large hail so we will stick with a level - 1.

... Slovenia, parts of Hungary and Romania, Serbia, Montenegro, Bosnia and Herzegovina and Croatia ...

Latest synop and sounding data from those regions reveal a well mixed BL with limited moisture as dewpoints are at or above 10°C. The main focus for initiation will be a southward racing cold front and the airmass ahead of this front should become more humid. Steep mid - level lapse rates atop this BL will support MLCAPE values in the range of 1000 - 1500 J/kg if progged dewpoints are correct. DLS of 10 - 15 m/s is more than adequate for a few large hail reports and hence a broad level - 1 will be issued. Another focus will be the eastern parts of the cold front as scattered storms should evolve along this S / SE-ward racing front . Better LL and mid - level flow pointing into the front ( 15 m/s at 850 hPa ) could result in numerous strong and isolated severe wind gust reports as far east as W - Romania, but decreasing instability should limit the severe risk further towards the east.

# # #