Meteoitaly.it Forum

A level 1 and level 2 are issued for N Italy, S Switzerland, S Austria and Slovenia for large hail, flash floods and to a lesser degree severe convective wind gusts, in NE Italy also for tornadoes.

DavideBassano ha scritto: ↑

ven lug 20, 2018 2:45 pm

A level 1 and level 2 are issued for N Italy, S Switzerland, S Austria and Slovenia for large hail, flash floods and to a lesser degree severe convective wind gusts, in NE Italy also for tornadoes.

peso che stavolta ci azzecchino , stare molto attenti .

The most robust severe weather threat evolves in the warm air advection regime on the southern side of the Alps.
A first vorticity maximum will facilitate numerous storms over the mountains of NE Italy and S Austria from the early afternoon onwards. As soon as they detach from the mountains and tap into the thermal upvalley flow regime, they will encounter plentiful CAPE (around 1000 J/kg in S Austria and Slovenia, up to 2500 J/kg in N Italy) and increasing 0-6 km shear (around 15 m/s with slightly veering profiles). An organization into multi- or supercells is expected. The main risks are large hail (possibly approaching 5 cm in case of supercells) and flash floods, as the wind profiles and the orographic forcing will favor side- and backbuilding. The risk of a few severe downbursts increases as well in case of upscale growth. It is likely that an MCS with an ongoing severe weather risk will move from S Austria into Slovenia before it gradually decays in the evening.
Secondary storms may initiate along outflow boundaries in the NE Italian forelands, where a CAPE maximum and enhanced low-level shear are expected in the sea breeze regime. Some convection-resolving models showed a dangerous scenario with strongly right-moving supercells zipping along the sea breeze front, which would enhance the tornado chances considerably next to the mentioned other risks. A level 3 was considered for this area, but was discarded due to the lack of steeper lapse rates, which would favor more extreme hail and wind events, and due to the possibility that the capping inversion will hold.
Convective initiation will be more sluggish in NW Italy, but a second round of storms will probably detach from the western Alps by evening and travel eastward across Piedmonte and Lombardia after nightfall. The arrival of the main trough axis will likely keep at least scattered convection going through the night, possibly including one or two large clusters. Flash floods become a distinct possibility, especially in the Swiss Ticino and neighboring parts of Italy which may be exposed to intense storms for several hours. Discrete or tail-end storms may still be highly organized and pose additional risks of large hail and severe wind gusts under further increasing 0-6 km shear up to 20 m/s, if they manage to stay surface-based. The severe weather situation extends into Saturday.

Intanto nubifragio ed alcuni chicchi come noci

domani giornata top

Qua flop orto intatto

Anche da me flop totale. Orto totalmente integro.

bel temporalone senza danni,ottimo così

marcolino977 ha scritto: ↑

sab lug 21, 2018 10:00 pm

bel temporalone senza danni,ottimo così

Haia!!!

Altro nubifragio in corso su Rimini! Venite tutti, a breve la bozza finisce.