Convective Outlook: Thu 24 Oct 2019
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Thu 24 Oct 2019 - 05:59 UTC Fri 25 Oct 2019

ISSUED 18:45 UTC Wed 23 Oct 2019

ISSUED BY: Dan

A complex pattern will evolve on Thursday, with a largescale upper trough over the Atlantic slowly approaching the British Isles, but also absorbing a portion of the Iberian cut-off upper low as it becomes stretched and pulled northwards over SE England during the middle part of Thursday daytime. The net result will likely see an increase in precipitation coverage and intensity as two frontal boundaries straddling CS / SE England, Midlands and East Anglia become engaged by the increased forcing aloft. Given the presence of a weak thermal plume advected northwards from SW France, embedded deep convection will lead to the threat of heavy rainfall in places, bringing the risk of some localised surface water flooding. 

A few hundred J/kg CAPE seems likely within this plume, which may be sufficient for some sporadic lightning late morning and into the afternoon hours - however, given saturated profiles this aspect is rather uncertain, and confidence is too low to introduce a SLGT. However, we have added an additional area to better highlight where some sporadic lightning could occur - this may be upgraded to a low-end SLGT if confidence improves.

Elsewhere, the post-frontal environment will offer scattered showers in places, most frequent along exposed western and northwestern coasts. In general, the depth of convection will tend to be too shallow / restricted for much in the way of lightning. The deepest convection will be found over NW Scotland.