Storm Forecast
Valid: Tue 10 Dec 2019 06:00 to Wed 11 Dec 2019 06:00 UTC
Issued: Mon 09 Dec 2019 22:03
Forecaster: DAFIS

A level 1 was issued for N Tunisia, S Italy, Malta, Greece, and W Turkey mainly for excessive precipitation and large hail. Numerous waterspouts are expected close to the coasts.

SYNOPSIS

A deep trough is entering the Mediterranean and increases instability. The development of a low-level vortex in South Italy will be associated with a strong advection of PVA entering the Ionian Sea on Tuesday 10/12. A Rossby-wave breaking, evidently caused by the Alps, will result in a cut-off low later in the early morning of Wednesday 11/12.
Another trough in N Atlantic is approaching Ireland and the UK, with a strong WAA in SW Scandinavia. Some low-topped storms may produce a few flashes of lightning in the cold sector of the trough.

DISCUSSION

.... N Tunisia, S Italy, Malta, Greece, and W Turkey ....

During the first half of Tuesday 10/12, a strong northerly flow over Tunisia will bring unstable air masses and storms may produce excessive rainfall or small hail. During the afternoon, the flash-flood threat will be shifted in S Italy, Greece and W Turkey. A strong low/mid-level flow over S Greece will increase DLS to 15-20 m/s, overlapping with 400-800 J/kg. A few large hail events are expected in Crete and South Aegean, while excessive rainfall is expected in Central Greece and the coasts of Turkey where PWAT will exceed 20 mm and NWP models forecast strong convergence zones. Storm activity will continue in the morning of Wednesday 11/12 in the Aegean Sea, mostly over the sea.
Numerous waterspouts are expected close to the coasts, especially in the Ionian Sea, where conditions will be ideal: Moderate to high instability (400-800 j/kg MLCAPE), weak flow and steep low/mid-level lapse rates.