Storm Forecast
Valid: Mon 21 Sep 2009 06:00 to Tue 22 Sep 2009 06:00 UTC
Issued: Sun 20 Sep 2009 18:23
Forecaster: DAHL

A level 1 was issued across the Ionian Sea and S Italy mainly for excessive convective precipitation.

A level 1 was issued across the SW Mediterranean Sea mainly for excessive convective precipitation.

SYNOPSIS

Upper flow over Europe is split into two branches, one rather intense, meandering one across the northern parts, and a weaker one covering the S Mediterranean, leading around an elongated upper low over SW Europe. Another upper cut-off cyclone is persent over N Turkey. The meandering northern frontal zone is accompanied by strong cyclonic low-level flow over the northern parts of Europe while synoptically quiescent conditions prevail over the rest of Europe. Main threat this period will be heavy convective rainfall across the Mediterranean, with two foci over the Ionian region and the western Mediterranean regions.

DISCUSSION

... Ionian regions ...

Upward forcing at the E periphery of the SW European upper low will affect the Ionian region on Monday. CAPE on the order of 1000 J/kg, weak capping, strong low-level moisture and slow storm motion suggest that clustering into weakly organized MCSs may occur. This activity will pose a threat for excessive convective rainfall throughout the period. Strong low-level buoyancy suggests that non-mesocyclonic tornadoes may occur, as well.

... SW Mediterranean ...

A very similar situation will be present across the western Mediterranean Sea, except that the boundary-layer moisture content will be somewhat lower. However, locally exessive rainfall as well as waterspouts may occur here, as well.

Elsewhere, severe convective weather threat is anticipated to be negligible.