Storm Forecast
Valid: Wed 28 Jan 2009 06:00 to Thu 29 Jan 2009 06:00 UTC
Issued: Tue 27 Jan 2009 23:23
Forecaster: PUCIK

SYNOPSIS

A broad, mid-level cut off low will continue to influence the weather over the Mediterranean. Otherwise, rest of Europe should stay under the weak ridge, stretching from Spain to Scandinavia, blocking off the depressions moving in from the Atlantic. On the surface, a large high pressure system will build up with the center over the Northern Germany / Baltic Sea. A surface low, which is associated with the mid-level cut off low is forecast to slowly fill and move from the Tyrhennian towards the Ionian Sea. Its cold front will affect the Aegean Sea / Turkey by the beggining of the forecast period. A belt of strong southerly flow is observed in a close vicinity to the front.

A cold mid-level temperatures along with the synoptic scale lift observed with the cut-off low will lead to the release of a few hundred J/kg of MLCAPE and scattered thunderstorm activity is anticipated in the Tyrhennian, Ionian and southern part of the Adriatic Sea, slowly building during the day towards Greece and the Aegean Sea. Lack of wind shear precludes severe weather threat with these storms although few waterspouts might occur thanks to the high values of 0-3 km instability and lapse rates.

DISCUSSION

...Southern coast of Turkey...

Above mentioned cold front should serve as the focus for the thunderstorm initiation. Warm and moist airmass ahead of the front, combined with the enhanced synoptic lift should lead to the unstable environment, with MLCAPEs probably locally exceeding 500 J/kg. Strong flow along the front will result in high values of DLS, which should reach 20 - 25 m/s. Moreover, veering of the winds with height, especially in the coastal areas and further inland will increase the SREH values to more than 250 J/kg. Therefore, environment should be conducive to well - organized convection, including few supercells.

Large hail is possible with the stronger cells, especially supercells. A marginal threat of weak tornadoes / waterspouts will also exist, especially near the coasts, where the best instability / low level shear overlap is expected. Although not included in our threat schemes, a flash flooding will be possible, as strong convergence signals are simulated by GFS along with the fact, that storms should be back building, thanks to the parallel orientation of wind flow to the frontal zone. The combination of hail / tornado threat should warrant the issuance of Level 1. Threat will be the greatest by the morning hours and will quickly diminish by the noon.