Convective Outlook: Sat 25 Apr 2020
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sat 25 Apr 2020 - 05:59 UTC Sun 26 Apr 2020

ISSUED 20:11 UTC Fri 24 Apr 2020

ISSUED BY: Dan

Ridging aloft will gradually weaken during Saturday as a couple of upper vortices approx from the Atlantic. A broad zone of mid-level moisture will span from Ireland across the Irish Sea to Wales, SW England and the English Channel - within this zone, weak elevated convection may produce a few isolated showers. Diurnal heating inland will yield a couple hundred J/kg CAPE, and combined with low-level convergence and orographic forcing may encourage a few isolated showers to develop, especially near high ground.

Rather marginal mid-level lapse rates, fairly meagre CAPE, restricted depth of convective cloud and lack of any substantial upper support suggests the risk of lightning is very low (10%). Showers will generally decay during the evening hours as daytime heating subsides, although there may be an increase in dynamic (frontal) rain developing over parts of Ireland on Saturday night.

Overnight, the approaching upper vortex near NW Scotland will gradually result in increasing instability here, with scattered showers developing during the early hours of Sunday. Convection will likely be somewhat restricted in depth until after this forecast period, and so the risk of lightning here is also considered very low (10%).