Storm Forecast
Valid: Tue 19 Feb 2013 06:00 to Wed 20 Feb 2013 06:00 UTC
Issued: Mon 18 Feb 2013 22:06
Forecaster: TUSCHY

A level 1 was issued for parts of W-Turkey mainly for heavy rain and an isolated tornado risk.

SYNOPSIS

Southward extending surface high over Norway/Sweden and a weakening vortex over Poland continue with the advection of cold and dry air far south. Despite sporadic deeper and temporarily electrified convection e.g. over the S-Baltic Sea, no thunderstorm activity is anticipated. Thunderstorms remain possible over parts of the Mediterranean.

DISCUSSION

... Aegean Sea with westward facing coastal areas ...

A vorticity maximum over the Adriatic Sea (06Z) shifts rapidly east during the forecast period and enters the Aegean Sea during the end of the forecast. This feature assists in the development of a diffuse LL depression over E-Greece, which spawns a warm sector over most of the S/C Aegean Sea.

Better BL moisture beneath eastward advecting plume of steeper mid-level lapse rates assist in some low-end to moderate MLCAPE build-up in the amount of 400-800 J/kg. Phasing subtropical and weaker polar jets create roughly 25 m/s DLS, which is enough for a few better organized storms. Main focus for CI will be the eastward trailing cold front and scattered storms evolve along that boundary mainly after sunset. Gusty winds and isolated large hail are possible but the main risk looks like to be heavy rain as frontal boundary reveals only a slow motion to the E/SE. Dynamics are also supportive for upscale growth with placement beneath the exit region of a 30 m/s mid-level jet and good divergence aloft. Therefore a small rainfall level 1 area was added despite not healthy looking prefrontal moisture axis. I'll also mention a very low-end tornado risk for any storm, which rides along/ahead of the cold front to the NE. Offshore plume of better LL CAPE and some LL shear support that idea.

For the rest of the highlighted areas (e.g. Ionian and Adriatic Sea but also the far SW-Mediterranean and S-Spain), no severe risk is anticipated with isolated thunderstorm activity (despite locally heavy rain).