Valid: Wed 28 Sep 2011 06:00 to Thu 29 Sep 2011 06:00 UTC
Issued: Tue 27 Sep 2011 21:47
No threat levels have been issued.
SYNOPSIS and DISCUSSION
The main macrosynoptic feature influencing the scenario during the day should be a high pressure system centered over Western and Central Europe, increasing in size and amplifying towards north. Strong flow involving jet-stream and frontal systems will be deflected mostly to the north of the high, with one of the short-waves passing over Northern Scandinavia and the second one over Western Russia towards southeast. A tongue of warm airmass is advected on the western flank of the high towards the north, up to Southern Scandinavia, while eastern parts of Europe should be under the cooler airmass advection.
Thanks to the vast area of high pressure, conditions will be mostly unfavorable for the thunderstorm development, especially over northern parts of Western and Central Europe. Current thinking is that most of the thunderstorm activity will be cofined to the Central Mediterranean, with the highest chances south and southeast of Sicily. The reason for this is a pool of lower temperatures at mid-levels overspreading the high SST and thus increasing the lapse rates. Nevertheless, due to the weak wind shear and absence of strong synoptic scale forcing, severe weather threat will be too low to warrant a Level.