Storm Forecast
Valid: Sun 02 Feb 2020 09:00 to Mon 03 Feb 2020 06:00 UTC
Issued: Sun 02 Feb 2020 08:56
Forecaster: PISTOTNIK

A level 1 is issued for E Germany, the Czech Republic, SW Poland, Slovakia and NE Austria for severe convective wind gusts and to a lesser degree for tornadoes.

SYNOPSIS

A very strong zonal flow persists with an axis from the Celtic Sea to the Black Sea. An embedded mid-level trough over E Europe departs to the east. Over central and W Europe, the mid-level flow turns slightly anticyclonic, supported by strong warm air advection in the warm sector of another storm cyclone NW of the British Isles.
Mild and calm weather continues over the Mediterranean region.

DISCUSSION

... central Europe ...

A further sharpening frontal boundary near 50N acts as a warm front during daytime, before it becomes stationary overnight. Similiar to the previous day (though in a more subtle way), a vorticity maximum in the left exit of of >50 m/s mid-level jets streak will overrun the very mild and moist air in the warm sector in the second half of the forecast period, stretching and thus destabilizing it.
Precipitation will break up into bands of showers and probably low-topped thunderstorms after 21 UTC from north-central Germany to Slovakia. Under very strong shear (0-1 km: 15-20 m/s, 0-3 km: around 25 m/s), multicells and small bow echos are expected and pose a risk of severe wind gusts. In case of discrete updrafts, transient supercells with an enhanced tornado risk are not ruled out.

Further south and on the anticyclonic side of the mid-level jet streak, a narrow rain band is predicted to form across E France and SW Germany overnight, roughly between Paris and Munich. It will remain almost stationary before it slowly starts shifting south towards Monday morning. It is not expected to grow deep enough to produce lightning and severe convective weather. However, a low-level "barrier jet" north of the Alps on its warm side will bring strong to severe non-convective wind gusts along with possibly record-breaking nighttime temperatures (above 15C).