Flash flood alert in Italy

[Jack92jk]

Forecast valid from Sunday 14 July to 21:00 until 23:59 of Monday 15 July 2019

Synoptic

A small cold drop in the next few hours will approach the western Alps determining, from today's late evening, rains and thunderstorms over most of northern Italy.

Subsequently, the translation towards the south-east of the same, will determine strong thunderstorms on the Tyrrhenian, Corsica and Tuscany with flash flood risk for different areas.

Thunderstorms will often be stationary causing hydrogeological stress conditions, due to the low jet present at high altitude and the little mobile convergences that will be established here and there on the Italian western basins.

Even Sicily will see relevant phenomena, in fact it will be dominated by a branch of the jet streak with intense thunderstorms moving from west to east ..

Piedmont, Lombardy and Emilia Romagna

Rains and thunderstorms that already from the late evening of today will affect the high plains but that during the night and morning will tend to conquer the lowlands.

The greatest risks will derive from the accumulations, locally very high, with the risk of flooding and inconvenience. Western and southern Piedmont and Emilia Romagna are under observation.

The continuous rains with the passing of the hours will replace the thunderstorms due to the lack of energy available to the convection

Liguria, Tuscany, Corsica and Sardinia

An intense south-east flow will blow from the Tyrrhenian Sea up to the Ligurian gulf carrying with it a fair amount of energy (up to 1500J / kg).

Just on the gulf a clear convergence will be established, already in the early hours of the day, between the north wind that will devalue from the Ligurian Apennine passes and the sirocco rising from the south east, with very violent thunderstorms that will mainly affect the open sea and the finger of Corsica (level 3).

There should be no major risks to the Ligurian coast with phenomena "filed" by the presence of the north wind in the lower layers.

Also in the morning strong storms will affect the island of Elba and southern Tuscany, with risk of flash floods and severe traffic disruptions.

In this area, thunderstorms will persist in alternate phases until the late afternoon hours, with the possibility of waterspout also trespassing along the coasts, be careful.
Some phenomena will also affect the North of Sardinia but no criticalities are expected.

Sicily

This region will be crossed by a branch of the jet streak with clear and sudden destabilization of the air column. The first thunderstorms will be formed on the north of the island during the early afternoon resulting immediately intense (level 2-3).

The phenomena will ride the jet stream, moving rapidly to the east and also affecting the eastern areas of the island by evening.

Also in this case the greatest risks will derive from the huge accumulations. The hailstorms will be at most medium-small size.

Jacopo Zannoni

The member of the storm chasers group ZenaStormChaser from Genoa, Italy. Follow ZenaStormChaser on Facebook, Instagram or Twitter