Convective Outlook: Fri 18 Dec 2020

LOW SLGT MDT HIGH SVR

What do these risk levels mean?

Convective Outlook

VALID 06:00 UTC Fri 18 Dec 2020 - 05:59 UTC Sat 19 Dec 2020

ISSUED 10:50 UTC Fri 18 Dec 2020

ISSUED BY: Dan

Showery outbreaks of rain spreading northeastwards across England and Wales have the potential to produce a few isolated lightning strikes during the forecast period courtesy of embedded elevated convection. Given the strongly-sheared environment, some line convection seems plausible at times along the trailing cold front. The post-frontal environment is then characterised by cold air overspreading relatively warm seas, and hence increasing instability and numerous showers developing across Ireland overnight, these moving into western Britain during the early hours. A few isolated lightning strikes may be possible with this activity, perhaps more especially Celtic Sea and parts of W / SW Ireland (15-20% chance), although the deepest convection (and therefore higher risk of lightning) will probably be reserved for Saturday daytime, beyond this forecast period - and so for now, have refrained from introducing a SLGT.