Storm Forecast
Valid: Wed 15 Sep 2010 06:00 to Thu 16 Sep 2010 06:00 UTC
Issued: Tue 14 Sep 2010 23:06
Forecaster: PUCIK

SYNOPSIS

The main macrosynoptic feature at midlevels will be a large cyclonic vortex that will cover most of Northern Europe. At Wednesday 12 UTC it will be centered over Southern Norway with slow movement to the east. Several vorticity maxima are expected to rotate around it in the strong flow surpassing 20/25 m/s at 500 hPa level. To the south, one cut off low will approach the Iberian penninsula, especially towards the later forecast period. Another one will be located to the south of Sicily.

At the surface, low pressure system located underneath the mid and upper level low will have two distinct centers. The first one will translate towards the south along the coastline of Norway whereas the second one will follow the vorticity maxima and mid-levels and will cross Denmark and Southern Sweden. Frontal zone will stretch from Northern France to Germany, the Czech Republic, Southern Poland, Belarus into Russia.

DISCUSSION

No prominent area with severe thunderstorm risk is forecast for this day. Especially with the vorticity maxima and deep low pressure system crossing Southern Scandinavia into the Baltic Sea and progressing northwards. Areas with strong synoptic scale forcing along with high values of wind shear lack sufficient amount of instability to promote severe thunderstorm formation. Nevertheless, narrow frontal rainband ahead of the vorticity maxima is possible with its circulation possibly enhancing the wind gusts, which will be mostly induced by a synoptic scale pressure gradient.