Storm Forecast
Valid: Mon 15 Jul 2019 06:00 to Tue 16 Jul 2019 06:00 UTC
Issued: Mon 15 Jul 2019 01:39
Forecaster: VAN DER VELDE

A level 2 was issued across Corsica and Ligurian Sea mainly for excessive rainfall and tornadoes.

A level 1 was issued across Italy mainly for excessive rainfall and tornadoes.

A level 1 was issued for Romania, Ukraine, Belarus, Russia mainly for excessive rainfall.

A level 1 was issued for N Turkey mainly for excessive rainfall and tornadoes.

SYNOPSIS

A large area of weak low pressure and associated thunderstorm activity stretches from SE Europe to NW Russia. With a high over the British Isles, a northerly flow is maintained over western Europe, moving cooler air into the Mediterranean Sea, where a low has formed in the lee side of the Alps. This low tracks slowly across Corsica and Italy. Other lows are found over Sweden/Finland, and the southern Black Sea.

DISCUSSION

...SE France, Corsica and west coast of Italy...

The Genua low at the start of the period is still near the FR/IT border, but already generated convection over the Liguarian Sea and Corsica at night. CAPE of 500-1000 J/kg, DLS over 20 m/s and SREH over 300 m2/s2 with 10 m/s LLS remain in the vicinity of the center of the low until about 15Z, when slowly moving over Corsica. The enduring convergence zones and shoreward flow will likely trigger intense convective cells with excessive precipitation threat thanks to slow storm movement, and can produce tornadoes (or waterspouts) and large hail.
Later, at night, the focus shifts to southern Italy with similar threats. There is more CAPE and drier mid levels forecasted, as well as elevated instead of BL-rooted convection. Severe wind gusts may occur here.
Over Sicily, the early hours of Monday a shortwave trough passes with 35 m/s DLS and SREH of 300-500 m2/s2. This activity should leave the area during the morning but can produce large hail and severe wind gusts.

...Eastern Europe...

Very weak flow will enhance the chances of local excessive precipitation from storms.

...N Turkey...

A low will be dissipating but still can produce organized convection. In the east of the level 1 the shear values are supportive of supercells while in the west a high vorticity area can produce tornadoes by spin-up, with shoreward flow may trigger an excessive precipitation event if a storm still forms in the diminishing CAPE environment.