Storm Forecast
Valid: Fri 02 Nov 2007 06:00 to Sat 03 Nov 2007 06:00 UTC
Issued: Thu 01 Nov 2007 17:32
Forecaster: TUSCHY

SYNOPSIS

As winter is around the corner and hence the atmosphere gets more dynamic it maybe makes some sense to first have a look on how good models like GFS handle the current pattern .
Latest forecast of the standard deviation of the NCEP ENS for 00Z, 3d Nov. show strongest deviation north of the Black Sea as a result of a southward building upper-level trough. This in fact could still mean some shift in the final trough position but won't have any significant affects on our thunderstorm forecast, because activity should be confined to the cold front and quite limited. We went ahead and highlighted areas, where conditions looked prime for a somewhat enhanced thunderstorm risk, mainly where boundary layer moisture will be good and timing will be the best ( regarding diabatic heating ).

Another area of enhanced uncertainty will be southern Norway. Nearly all models agree in track and strength of this depression although timing is somewhat more unclear. Expect the depression to reach central Norway during the latter part of the forecast period. Attendant strong wind field should start to affect most parts of southern / central Norway, but a bad thermodynamic stratification will keep thunderstorm probabilities down and only an isolated SFLOC report along the coast can be expected.

We also went with a small thunderstorm area over northern Norway / Finland and parts of extreme western Russia as intense CAA overspreads the area of interest during the morning hours. SSTs of 7-8°C should be enough for some instability release along the coast before shallow moisture layer gets mixed out.
In all areas, decribed above the main severe weather risk will be an isolated tornado threat. As LL shear will be enhanced, instability won't be impressive and EL temperatures stay quite warm we do not think that convection associated with funnels/short-lived tornadoes has to be electrified .

Numerous thunderstorms are forecast under the weak upper-level low pressure channel over the central / eastern Mediterranean. Shear is too weak for an enhanced severe weather risk. Thunderstorms could produce gusty winds and isolated marginal hail.