Storm Forecast
Valid: Mon 25 Sep 2023 06:00 to Tue 26 Sep 2023 06:00 UTC
Issued: Sun 24 Sep 2023 18:26
Forecaster: DAFIS

A level 1 was issued across for parts of Italy, Albania, Greece and Malta for heavy rainfall, large hail, severe wind gusts, and tornadoes.

A level 2 was issued in South Italy for very large hail, damaging wind gusts, tornadoes and heavy rainfall.

A level 2 was issued in Greece and South Albania for very large hail, damaging wind gusts, tornadoes and heavy rainfall.

DISCUSSION

... South Italy and Malta...

On the northern flank of a cut off low that has entered the Ionian Sea, most of the available numerical models show a a high-vorticity disturbance crossing SE Italy on Monday night 25/9. It will create a favourable environment for large hail, severe convective winds and heavy rainfall, as mid- and deep-layer shear will exceed 15 m/s in a very unstable air mass. A few tornadoes in South Italy cannot be ruled out given the LLS and high CAPE.
In Malta, the main threats will be severe convective wind gusts and heavy rainfall.


... Greece and Albania ...

The high-vorticity mid-level cold drop promotes cyclogenesis in the Ionian Sea, and a high pressure gradient will develop over the Aegean Sea. Very moist air masses are found over Greece and Albania, where numerous storms will develop. On Monday, the main threat will be large to very large hail locally. High values of CAPESHEAR and steep lapse rates suggest that storms will be able to produce hail up to 5 cm in diameter. Strong to severe wind gusts are also possible. In the early morning on Tue 26/9, the main threat will be heavy rainfall in Central Greece. Training convection and orographic lifting will promote flash floods. Severe wind gusts will continue to pose a threat in eastern Greece on Tuesday. Tornadoes are also possible, especially close to the coasts where LLS is maximized.