Storm Forecast
Valid: Wed 03 Nov 2010 06:00 to Thu 04 Nov 2010 06:00 UTC
Issued: Tue 02 Nov 2010 21:41
Forecaster: PUCIK

SYNOPSIS and DISCUSSION

At midlevels, contrasting conditions will prevail over the different areas of Europe. Southwestern Europe and Turkey/Black Sea region will be under the influence of subtropical ridges while in between, a cut off low will stall, centered over the Tyrrhenian Sea. This cut off low will fill in, its center shifting slightly to the south. Western and Northwestern Europe will be placed under a strong, northwesterly flow of the polar jet-stream. A disturbance will quickly translate eastwards, embedded in the jet and positioned approximately over Denmark as of 12 UTC. Disturbance is expected to amplify slightly, resulting in a southwesterly upper tropospheric flow over Eastern Europe at its forward flank.

Closer to the surface, a deep low has settled over the Norwegian Sea. Its trough will travel along with the aforementioned disturbance and under the region of CVA, cyclogenesis is forecast in a stretch from Central Sweden to Southern Finland, resulting in a separate low center. A frontal system will be associated with this feature. Behind the cold front, advection of polar airmass will result in a low-end instability build-up with CAPE values reaching 100-200 J/kg over Denmark, the eastern part of the Northern Sea and the Baltic Sea. Along with strong 20 m/s flow at 850 hPa, numerous rounds of low topped showers or very isolated thunderstorms are expected with gusty winds. With little forcing in a post-frontal environment and low-end instability, severe weather threat is currently forecast to be too small to warrant a Level 1.

To the south, a surface low over the Central Mediterranean has started filling in, along with the weakening low level wind field and convergence, finally relieving the regions of Northeastern Italy from the intense rainfall from the previous days. Nevertheless, cool mid-levels and upward motion will likely result in a low to moderate degree of latent instability, especially over the Ionian Sea, as simulated by GFS and ECMWF. In the extent of this mid-level cut-off low, thunderstorms can be expected, but likely not reaching the severity from the previous days due to the weakening forcing and wind field.