Storm Forecast
Valid: Fri 26 Jan 2018 06:00 to Sat 27 Jan 2018 06:00 UTC
Issued: Thu 25 Jan 2018 17:56
Forecaster: PISTOTNIK

No threat levels are issued.

SYNOPSIS

An amplified upper-level trough stretches from Scandinavia to Spain and cuts off over the western Mediterranean Sea. Cool maritime air spreads southward across the British Isles, the Bay of Biscay and Iberia in its wake.
Most of southern and eastern Europe are under mild, anticyclonic conditions, as very mild air is advected far northeastward ahead of the trough. Only Turkey and Cyprus are still influenced by a slowly receding cut-off low with cooler and unsettled weather.

DISCUSSION

... coastal areas of S France and NW Italy ...

A surface cyclone forms off the Catalonian coast and drifts eastward. A few hundred J/kg of CAPE form in the southerly warm air advection regime ahead of it, helped by both synoptic and orographic lift. Limited area models predict a sharp convergence line at the cold front which slowly moves eastward. Heavy rain with embedded thunderstorms is expected. A level 1 is issued for a possibility of flooding if the convergence line stalls for a few hours. In addition, a waterspout is not ruled out under a combination of low cloud bases and strong convergence.
The risk shifts eastward towards Liguria while it slowly diminishes during the forecast period. Other kinds of severe weather are unlikely, as the vertical wind shear appears too weak to support storm organization. Offshore areas will likely stay devoid of thunderstorms due to a strong capping inversion and a lack of lift.

... other thunderstorm areas ...

Scattered thundery showers will form under little CAPE and weak vertical wind shear (cool air on top of mild water). Severe weather is not expected.