Storm Forecast
Valid: Fri 22 Feb 2008 06:00 to Sat 23 Feb 2008 06:00 UTC
Issued: Thu 21 Feb 2008 17:14
Forecaster: TUSCHY

A 70-80m/s jet at upper-levels stretches out from Scotland to Estonia and marks an intense temperature gradient at mid-/ upper-levels, disjoining very cold mid-levels over Norway and Sweden and 20K warmer mid-levels over central Europe at the same level. Numerous disturbances are embedded in this flow but none of them poses an enhanced thunderstorm risk.

A general thunderstorm area was issued for parts of Norway as low-end instability release looks likely in an environment with cold ELs. Rapidly easing instability onshore should suppress the risk for rotating storms as LL shear increases well inland. In addition, meager moisture at lower levels should keep thunderstorm coverage isolated.

A few thunderstorms are forecast southwest of Portugal. No severe weather threat expected with those storms.
The same for an area just south of Italy.

Latest GFS output still indicates some instability values over eastern Germany and central Poland between 00Z and 06Z, mainly the result of rapidly steepening LL lapse rates. Forecast soundings have the inversion at about 800hPa and coupled with a moderate T-Td spread at surface, confidence in enough instability release for an electrified updraft is too low for any risk level. Nevertheless, gusty winds could accompany convective segments along the cold front as winds at 850hPa increase to 25m/s.