Convective Outlook: Sat 01 Dec 2018
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sat 01 Dec 2018 - 05:59 UTC Sun 02 Dec 2018

ISSUED 14:07 UTC Sat 01 Dec 2018


UPDATE 14:07 UTC Confidence has improved in the expected forecast evolution during Saturday night, similar to the discussion below. The area with the greatest risk of some sporadic lightning appears to be the Celtic Sea during the evening hours, but probably weakening (if any) as this activity approaches SW Wales and SW England mid-evening onwards. Chance of lightning is, however, still considered sub-SLGT for now.

Main interest during this forecast period is during Saturday night, as the next Atlantic frontal system slides eastwards across Ireland and central/southern Britain. This will be associated by a tongue of high WBPT air, with notably warm/moist low-levels overspreading southern areas. This combined with an overlap of upper forcing will generate a few hundred J/kg CAPE, with the potential for some embedded elevated convection to develop, especially on the rear/southern-side of the precipitation envelope.
Some sporadic lightning seems possible, but there is an unusual amount of uncertainty over the exact track, and hence phasing of ingredients, to be able to narrow down the areas at greatest risk. As such, this forecast may be updated if confidence improves in light of new data.