Convective Outlook: Thu 23 Aug 2018
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Thu 23 Aug 2018 - 05:59 UTC Fri 24 Aug 2018

ISSUED 05:33 UTC Thu 23 Aug 2018

ISSUED BY: Dan

Upper trough and associated cooling aloft will overspread northern portions of the British Isles during Thursday, steepening lapse rates and generating a few hundred J/kg CAPE. Behind the secondary cold front, numerous showers are likely to develop during the afternoon and evening hours, persisting overnight in areas exposed to the northwesterly wind. Some gusty winds and small hail will be possible with the strongest cores, and while there could be a few lightning strikes rather weak shear and marginal instability suggests that lightning activity will tend to be rather isolated / sporadic and hence difficult to highlight any specific areas with a greater risk.


The secondary cold front will also become more convective in nature by Thursday afternoon as it moves across north Wales, northern England and the north Midlands. Instability will be marginal, but with a strongly-sheared environment there will be scope for some line segments to develop, which could produce some isolated/sporadic lightning and strong gusts of wind. A low-end SLGT has been issued to highlight the region of interest, but there will likely be many areas within the SLGT that remain void of lightning.