Convective Outlook - Wednesday 23/09 #ukweather SLGT risk Squally showers and well-scattered thunderstorms possible for parts of the UK with the greatest risk perhaps focused across parts of southern N England into E Mids and northern East Anglia late morning and into the early afternoon. Convection could organise into line segments capable of producing gusty winds up to 45-50mph, with very isolated instances of >50mph gusts should more robust storms materialise (low likelihood). Thundery showers are also possible across E Ireland, the Irish Sea, and into N Wales earlier in the morning. Discussion: An upper-level shortwave will translate west to east across the UK and Ireland throughout Wednesday, with its axis expected to clear eastern England by mid-afternoon, with 500mb temps falling to -24C to -25C within the core traversing across N/C Scotland and the -20C isotherm perhaps digging into far N Midlands. Ample ascent ahead of the trough axis (strong PVA + upper-level diffluence) will overspread a high-theta-e low-level airmass advected NE ahead of an advancing cold front. Earlier guidance was not concrete regarding the exact track of this feature, with some solutions allowing the -20C isotherm to extend much deeper into the Midlands and East Anglia. Such solutions would have promoted a much more favourable thermodynamic environment for robust convection to develop with MUCAPE potentially reaching 800-900 J/kg across E Yorks, parts of E Mids, and East Anglia by late morning/early afternoon, although these higher-end solutions have now been dropped by guidance and thus only a broad SLGT polygon has been issued. Convective activity could begin earlier in the morning from E Ireland, the Irish Sea, and across parts of N Wales as the shortwave approaches. Magnitude of instability will be more limited here owing to weaker diurnal heating although focused ascent of the high theta-e airmass along the cold front and via orographic lift (Wales) may assist in CI and develop thundery showers within broader heavy, dynamic rainfall with isolated gusts of 40-45mph possible from any deeper convection. Isolated lightning is also possible across S/E Scotland during this earlier period. Further east, the environment may become increasingly supportive of organised convection during late morning and into the afternoon as surface heating lifts temperatures into the high-teens to low-20s C ahead of the cold front, with strong synoptic forcing overspreading eastern England with the advancing shortwave. A deep moist layer extends from the surface-700mb, with especially dry air above 600mb advected into the region - this will promote steeper lapse rates and enhance downdraft acceleration with any deeper convection. Strong speed shear throughout the atmosphere will help organise showers/storms into multicell clusters/line segments as they progress eastwards with time and could bring the threat of isolated wind gusts >50mph, more widely 40-45mph, should any bowing segments develop.

Está tormenta tiene un potencial altísimo, por suerte se quedará en el mar y no afectará a Baleares, eso sí se espera que pueda llegar a Cerdeña con rachas de viento superiores a 120-130km/h!!⛈️⚠️ Los topes de nube rozan los -75°C, algo que indica la severidad de este monstruo. #euwx #Meteo #Weather #severewx

#ukweather Heavy rainfall pushing across parts of Scotland this evening, with embedded deep convection and torrential elements (notably just NW of Glasgow currently). Some lightning activity associated with this as it tracks NE. Embedded shortwave and intense upper cold pool (500mb temps down to -25C) steepening lapse rates enough to yield weak instability to fuel some stronger updrafts.