Storm Forecast
Valid: Tue 15 Dec 2009 06:00 to Wed 16 Dec 2009 06:00 UTC
Issued: Tue 15 Dec 2009 05:36
Forecaster: VAN DER VELDE

A level 1 was issued for coastal regions of the Mediterranean Sea mainly for excessive convective rainfall.

SYNOPSIS

An intense and large low pressure area affects the central Mediterranean area. The airmass is unstable with up to 1200 J/kg MLCAPE around Greece and Turkey, leading to many storms which can persist in coastal convergence zones for hours. Strong lifting is present on the east flank of the upper trough by low level warm air advection.

DISCUSSION

...Greece and Turkey...

Excessive rainfall should be the primary threat. Besides that, marginal SREH 100-200 m²/s², deep layer shear around 15 m/s and low-level shear >12 m/s are in place for generation of mesocyclones over both Greece and Turkey, moderate SREH over western Turkey during the evening, where as usual the instability source (sea) and shear source (friction) do not quite overlap so nicely however. In the strong flow, some convective gusts may reach 25 m/s. GFS indicates strong 0-3 km CAPE >200 J/kg values good for spinning up waterspouts.
The jet is offset to the south which is a limiting factor for severe weather other than precipitation. It touches upon SW Turkey during evening and night.
Massive QG lift and SREH>300 m²/s² should arrive at the very end of the forecast period for southern Turkey and Cyprus which may qualify for level 2 on Wednesday.

Isolated waterspouts are possible in the entire unstable area.