Storm Forecast
Valid: Wed 04 May 2011 06:00 to Thu 05 May 2011 06:00 UTC
Issued: Wed 04 May 2011 06:18
Forecaster: PUCIK

A level 1 was issued for Southwestern Turkey for marginally severe hail and wind gusts.

SYNOPSIS

The main macro-synoptic player will be a deep low at mid and upper levels of troposphere, its center stagnating over the Baltic Sea. Strong southerly flow is observed on its forward flank and its trough extends far into the Southeastern Mediterraean. Mainly the low, but also the trough are filled with seasonably cold mid-level temperatures, which advect towards southeast during the day, in conjuction with northwesterly flow on the forward flank of a ridge that is amplifying over Western Europe.

As a cold front advances across Southeastern Europe in the direction of the prevailing northwesterly flow, thunderstorm threat areas will also shift to the regions, where cool mid-level temperatures overtop relatively warm airmass closer to the surface, yielding higher lapse-rates. Nevertheless, with lack of concentrated lift and meager low-level moisture, only marginal values of CAPE are simulated. The highest coverage of thundrestorms will probably be observed over Southeastern Europe, specifically in the proximity regions to the coasts of the Ionian and Aegean Seas.

DISCUSSION

... Southwestern Turkey ...

Marginal values of CAPE reaching values on the order of hundres of J/kg should be overlain by a strong southwesterly flow (with jet-stream at 300 hPa exceeding 40 m/s), yielding moderate to strong and deep vertical wind shear profiles. Shear in 0-6 km layer is simulated to reach over 25 m/s and in 0-3 km layer over 15 m/s. Moreover, some marginal SREH values, approximately at 150 J/kg in 0-3 km layer is simulated as well. In such conditions, despite low CAPEs, well organised convection, including low-topped supercells, is possible, along with threats of marginally large hail or severe wind gusts. Severe gust threat will be most prominent inland, where drier airmass low-level airmass is forecast. Low-end Level 1 is issued for the region, having in mind the fact, that the region with the most favorable conditions will probably experience the lowest coverage of storms and vice versa.