Convective Outlook: Sat 18 May 2019
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sat 18 May 2019 - 05:59 UTC Sun 19 May 2019

ISSUED 06:05 UTC Sat 18 May 2019


Broad upper trough covers much of central and western Europe on Saturday. Provided sufficient cloud breaks develop, heating of a very moist low-level airmass will yield 100-200 J/kg CAPE. This combined with low-level convergence and orographic forcing will likely lead to scattered showers developing during the late morning / afternoon / early evening hours across many (largely inland) parts of England / Wales / S Scotland / Republic of Ireland.  Weak shear, meagre instability and a warm nose acting as a cap at 700mb suggests the risk of lightning is rather low, but ample low-level moisture and slow-moving nature of showers could lead to some localised surface water issues.

Showers will tend to weaken during the second half of the evening as daytime heating subsides. However, elevated instability will run northwards up the North Sea towards Shetland, and may produce some eleveated thunderstorms here late in the night towards Sunday morning. A small risk this may also affect parts of NE Scotland and Orkney.