Storm Forecast
Valid: Wed 12 Nov 2025 06:00 to Thu 13 Nov 2025 06:00 UTC
Issued: Tue 11 Nov 2025 13:42
Forecaster: TUSCHY

A level 1 was issued for Portugal and far NW Spain mainly for heavy rain and an isolated strong gust/tornado event.

A level 1 was issued for Cyprus mainly for heavy rain. An isolated tornado is possible.

SYNOPSIS

An stationary wave pattern evolves over SW Europe, featuring an anomalous intense upper trough W of the Iberian Peninsula and a building ridge over the CNTRL Meidtrranean. This pattern results in a multi-day heavy rain risk for Portugal/Spain.

A COL evolves over NW Europe with a captivated warm front over parts of S/CNTRL UK. Spotty thunderstorms along the western periphery of the warm sector can occur. Another upper trough over SE Europe sparks numerous thunderstorms within a weak background shear setup.


DISCUSSION

... Portugal and far NW Spain ...

A modest atmospheric river event unfolds for the area of interest with TPWs in the mid to upper thirties. A dragging and wavy cold front slowly approaches Portugal from the W but remains just offshore or just inland during the forecast period.

During the day a strong WCB with an embedded 50 kt LL warm jet impacts most of the level 1 with prolonged onshore flow of moist/unstable air and cross-isentropic ascent. Especially for the afternoon hours and during the night, the stage is set for repeatedly onshore moving showers and thunderstorms, which produce heavy rainfall amounts (40-80 l/qm in 12h with local higher peaks). In case thunderstorms cross urban areas for some time, flash flooding is possible.

Beside the rain risk, ample MUCAPE with strong shear support organized updrafts with some graupel and strong gusts. Severe gusts are possible in higher elevations, atop any LL inversion and placed in the warm jet core.
Regarding the tornado risk, especially S Portugal has lingering H85 cap issues, although CIN magnitude varies in NWP guidance. Not much modification is needed for strong LL shear and extreme helical inflow for an evolving tornado risk with any more discrete cell or along line breaks. An isolated event cannot be ruled out. The highest risk runs from far S into SW Portugal.

The general risk continues beyond 06Z.

... S Ireland and SW UK ...

A gradually northward spreading warm sector with ongoing isentropic ascent offers lots of cloudiness and precipitation. Hence the stratification of the warm sector remains rather stable. However a few thunderstorms are possible next to the cold front with healthy rainfall rates and some gusts.

... Cyprus ...

1000 J/kg MUCAPE with 10-15 m/s DLS result in a few better organized multicells with heavy rain and isolated hail.