Storm Forecast
Valid: Sat 31 Mar 2007 09:00 to Sun 01 Apr 2007 06:00 UTC
Issued: Sat 31 Mar 2007 09:06
Forecaster: DAHL

SYNOPSIS

Large-scale upper low remains anchored over the Gulf of Biscay through the period ... maintaining weak but rather extensive SFC low over the Iberian Peninsula and the SW Mediterranean regions. Weakening upper trough located over the Aegean region on Saturday morning, which is also accompanied by a weak SFC low, should continue to deamplify while laving the forecast area to the east. Northern and central portions of Europe are affected by a large SFC high pressure area.

DISCUSSION

... E Aegean ... W Turkey ...

Powerful DCVA is overspreading the E Aegean and W Turkey at the moment, and associated vertical motion regime should support increased TSTM development during the next few hours. Shear profiles should be strong enough to support multicellular storms, possibly containing at least brief mesocyclones. Main threats should be marginally severe hail and strong outflow winds. Strong SRH has been observed, and is simulated to persist, across E Turkey where the threat for supercells should be highest. LL shear and LL buoyancy seem to be somewhat limited and tornadoes should not be the main issue today, though an isolated event or two cannot be completely discounted, either.

... W Mediterranean ... Iberian Peninsula ...

Convection over the W Mediterranan, and in the modified polar air over the Biscay and Iberia, is anticipated to develop in rather weakly sheared anvironment and given minimal CAPE, severe threat should be rather low. However, as LIBR 00Z ascent from Saturday indicated, rich LL moisture has locally accumulated, resulting in favorably LL buoyancy for a few waterspouts. More organized storms may form late in the period over the SW Mediterranean where weak cyclogenesis will provide augmented LL shear and low-level forcing for ascent. Chance for multicellular storms capable of marginally severe hail and strong wind gusts exists, but signals in the CAPE fields are currently too weak to warant a categorical risk.