Storm Forecast
Valid: Sun 13 Feb 2022 06:00 to Mon 14 Feb 2022 06:00 UTC
Issued: Sat 12 Feb 2022 21:32
Forecaster: GATZEN

A level 1 was issued across north-western Spain mainly for severe wind gusts and a brief tornado threat.

SYNOPSIS

In the wake of a short-wave trough moving east, Europe is affected by mid-level ridging. Subtle flow is expected across the Mediterranean in the range of weak mid-level vortices centered over the Aegean, Balkans, and Gulf of Lion. Despite some steeper lapse rates within the mid-level troughs, rather dry and cool boundary layer air mass allows for only weak, low-topped showers, and lightning is not forecast.

Western Europe is affected by a deepening Atlantic trough, and its mid-level vorticity maximum will be located from the British Isles across the Bay of Biscay towards the central Iberian Peninsula by the end of the period, where a few thunderstorms are forecast.

Ahead of this vort-max, a tropopause fold will move into western Europe, with a potential of a narrow cold-frontal rain band. Instability will be low-topped from north-western France towards the British Isles, with no expected thunderstorm activity. However, some stronger wind gusts or a brief tornado are not ruled out in the evening and night.

DISCUSSION

North-western Iberia

Tropopause folding and associated low-level lapse rates increase is expected across north-western Spain in the afternoon. Due to rich low-level lapse rates, weak CAPE can develop below the PV intrusion. Frontal lift ahead of an approaching cold front will be rather strong, and a narrow cold-frontal rain band with embedded thunderstorms is forecast.

Due to strong low-level flow in addition to low cloud bases, with 1 km winds around 20 m/s and strong low-level vertical wind shear, some stronger updrafts are not ruled out, and mesovortices are not ruled out, posing a threat of severe wind gusts or a brief tornado. As the trough moves north-east, lapse rates are expected to decrease, and storms will decay.