Convective Outlook: Sat 06 May 2023 |
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What do these risk levels mean? |
VALID 06:00 UTC Sat 06 May 2023 - 05:59 UTC Sun 07 May 2023
ISSUED 06:33 UTC Sat 06 May 2023
br> br>ISSUED BY: Dan
Omega block persists across Scandinavia on Saturday placing the British Isles under the influence of an upper trough, albeit the main axis lifting northwards through the day with heights rising from the south with time. A rather messy pattern is anticipated with several low-end SLGTs introduced, most shower activity linked to shortwaves rounding the base of the longwave upper trough in conjunction with surface heating of a moist low-level airmass (Td typically 10-13C) yielding a few hundred J/kg MLCAPE, and orographic forcing/low-level convergence. One shortwave over S/SW Scotland at 06z will lift northwestwards to overlap favourably with peak heating across the NW Highlands, and it is likely several heavy showers and perhaps a couple of weak thunderstorms may develop here. Additional heavy showers may also develop through the day in S/SW Scotland across to the Borders and southwards into the northern Pennines/Lake District, perhaps with a few isolated lightning strikes. With showers training over the same area (or at least nearby), there is the risk of some local surface water flooding here.