Storm Forecast
Valid: Fri 24 Nov 2017 06:00 to Sat 25 Nov 2017 06:00 UTC
Issued: Thu 23 Nov 2017 17:31
Forecaster: PISTOTNIK

No threat levels are issued.

SYNOPSIS

A strong cyclone covers the Norwegian Sea, parts of Scandinavia and the British Isles. Its long and wavy cold front slowly moves SE-ward into central and western Europe, followed by maritime polar air.
Quiescent late-autumn conditions prevail over southern and eastern Europe under a large anticyclone.

DISCUSSION

... N France across Belgium into NW Germany ...

A distinct frontal wave travels ENE-ward along the cold front. It struggles to deepen as it stays on the anticyclonic side of a mid-level jet streak, but a compact vorticity maximum will overrun it and will expose the mild and very moist, neutrally stratified air along its warm side to strong synoptic lift in the 06 to 12 UTC time frame. The release of minimal CAPE (possibly slantwise rather than upright) may temporarily break up the rain band into short shower lines with little lightning activity near the tip of the frontal wave.
The passage of a transient wind maximum with 25 m/s at 850 hPa in the warm sector suggests a possibility of isolated severe wind gusts in case this convection manages to root down to the surface. However, this scenario is too conditional for a level 1.
The patch of synoptic lift decouples from the frontal wave after 12 UTC, hence the lightning activity - if any - will soon fade afterwards, No deep convection is expected anymore while the frontal wave continues to travel towards the Baltic Sea and southern Finland.

... Scottish W coast and parts of the North Sea ...

Disorganized cold-air convection will form in the polar air. Lightning activity will be limited and severe weather is not expected.