Storm Forecast
Valid: Tue 07 Feb 2017 06:00 to Wed 08 Feb 2017 06:00 UTC
Issued: Mon 06 Feb 2017 22:06
Forecaster: DAFIS

A level 1 was issued for SE Greece and SW Turkey mainly for excessive precipitation, large hail and severe wind gusts.

SYNOPSIS / DISCUSSION

A wide mid-level cut-off low is found over the central parts of Mediterranean Sea, associated with a low pressure system at the surface over Italy, both progressively moving east during Tuesday. A long-wave trough is approaching from the Atlantic, with large amounts of vorticity providing lift to moist air masses and several storms are expected west of France.

SE of Italy, several low-level vortices create a complex frontal activity and regarding the upper-level troughs, widespread thunderstorm activity is expected, mostly over the sea, where modest CAPE is produced. A decaying cold frontal system pushes warm and moist air masses over Greece tonight. These masses are characterized by mixing ratios up to 10 g/kg and steep mid-level lapse rates. Enhanced potential vorticity fields suggest additional lift to the subtle low level convergence zones over the Aegean Sea and if we take into account the steep orography of W Turkey, excessive precipitation is forecast due to persistent slow moving thunderstorms training along the coasts. Moreover, strong wind shear 0-6km if predicted over the level 1 area, overlapping with 400-800 J/kg CAPE and high delta theta-e values, so some multicells could be capable of strong downbursts and large hail (up to 2 cm). Finally, waterspouts cannot be ruled out within the 15-50% lightning probability areas, where favorable convergence zones will form and SST exceeds 16-17°C (T850 will be about 3-4°C).