Storm Forecast
Valid: Tue 20 Feb 2007 06:00 to Wed 21 Feb 2007 06:00 UTC
Issued: Tue 20 Feb 2007 02:25
Forecaster: VAN DER VELDE

SYNOPSIS

Two weather systems are responsible for areas of deep convection today:

1) the Mediterranean low, associated with deep shear (gradient of 15-35 m/s 0-6 km) and helical storm inflow (100-150 m2/s2 0-3 km) through the level 1 area around Crete,

2) postfrontal convection in a surface/mid level vorticity maximum (behind a long occlusion from Iceland to Morocco), probably not much lightning activity (Ireland, UK), in a zone of weak shear.

DISCUSSION

...southern Greece, Crete...

A few hundred J/kg MLCAPE and significant deep layer shear and some SREH may yield some rotating or long-lived storms (much like Sicily yesterday) with a chance of isolated large hail. Since low level shear is fairly weak, tornadoes are not very likely, although on the other hand good instability, lapse rates and weak flow could result in some waterspouts throughout the Mediterranean thunderstorm area. Crete is most likely to be affected during the evening and early midnight hours.