|Convective Outlook: Sun 27 Dec 2020|
|What do these risk levels mean?|
VALID 06:00 UTC Sun 27 Dec 2020 - 05:59 UTC Mon 28 Dec 2020
ISSUED 09:18 UTC Sun 27 Dec 2020br> br>
ISSUED BY: Dan
Large upper trough covers the British Isles throughout Sunday and Sunday night, with cold air atop relatively warm SSTs generating numerous showers over open waters, these then migrating inland on the (predominantly) westerly steering winds. Showers may merge to give longer spells of (wintry) precipitation at times, as various troughs/occlusions swing through in the flow. The greatest risk of lightning will be over open waters and adjacent coastal areas, perhaps with a slightly higher chance towards SW England during the night hours as an organised band of showers arrive from the northwest, approaching the Channel Islands towards the end of the night. As such, a low-end (25-30% chance) SLGT has been introduced. Squally winds and hail may accompany many of the showers, especially in western areas.