Deel NL en BE:
... NW France to S England / Belgium...
Behind the large stratiform precip shield of the warm front, in the strong southwesterly flow, models predict weakly unstable airmass, featuring almost indifferent vertical temperature gradient spreading across this region. Thanks to the very deep low, with its central pressure close to 970 hPa, intense low level wind field is forecast, with 925 to 850 hPa wind speeds approaching 35 m/s in the region of NW France and in the range of 25-30 m/s elsewhere. Forecast soundings/hodographs reveal very skinny CAPE profiles with unidirectional strong shear confined mostly to 700 hPa, with no further significant increase in windspeeds above this level. MLCAPE values should not exceed 500 J/kg, with more realistic predictions between 100-200 J/kg (per ECMWF/WRF simulations).
Deccelerating mid and upper level low, along with unfavorable position of the jet-streak during the development of instability over the region point to the reduced possibility of strong, concentrated forcing favoring rapid development of QLCS along the cold front. Nevertheless, scattered DMC is forecast, which should pose risk of severe wind gusts and tornadoes, especially thanks to the LLS exceeding 15 m/s. Threat should be the most prominent between 12-15 UTC timeframe, virtually ceasing after 18 UTC. An upgrade to Lvl 2, especially over NW France is possible if forcing or instability prove to be more favorable.
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