12-06-2025 22:26 | Estofex | m.b.t. 13-06-2025 t/m 14-06-2025
Storm Forecast
Valid: Fri 13 Jun 2025 06:00 to Sat 14 Jun 2025 06:00 UTC
Issued: Thu 12 Jun 2025 22:16
Forecaster: PUCIK
A level 2 was issued across parts of Spain, France and Belgium mainly for large to very large hail, damaging wind gusts and to the lesser extent for heavy rainfall.
A level 1 was issued across these countries for the same threats but with lower probability.
DISCUSSION
... W/NW France towards BENELUX ...
Uncertain situation is forecast also here, especially concerning the corridor of the most intense storms and their timing. A diffuse cold-front will linger over W France in the morning hours with some elevated showers or thunderstorms possible early on. Towards the afternoon, a wave is forecast to develop on the front ahead of the short-wave through at 300 hPa approaching from the south. As the surface flow turns towards east across north France, hot airmass with deep boundary layer will mix out the moisture and create a dryline with moist airmass to the west of it overlapping with steep mid-tropospheric lapse rates. Exact placement of the dryline is a main source of uncertainty. For example, ECMWF places it further west than the ICON-EU. Its location will be crucial in the placement of the corridor of the most intense storms.
Within the moist airmass, MLCAPE values of 1500 to 3000 J/kg are forecast, overlapping with 15 to 20 m/s of 0-6 km bulk shear. Thus, parameter space will be favorable for well-organised, severe storms capable of large to very large hail and damaging wind gusts. Storms will most likely start forming between 12 and 15 UTC over W France along the developing warm wave and will spread N and NE towards Belgium and England. A mix of supercells and linear segments is likely. Storms along the western fringe of the Lvl 2 and towards the western edge of the Lvl 1 will be elevated, but with still enough MUCAPE and effective shear for severe weather threat, most likely in form of large hail or heavy rainfall. As the low-level lift moves with the warm wave towards England, it is not very likely that storms spread far into the hot and drier airmass. This option can't be ruled out though and this led to a generous eastern and northern margin of the Lvl 1.
(alleen de voor NL en direct aangrenzende gebieden relevante tekstdelen overgenomen, klik hier voor de volledige forecast, red.)
Hagel(-schade) | Onweer/blikseminslag | Verwachtingen/waarschuwingen | Wateroverlast/(zware) neerslag
