Convective Outlook: Fri 30 Apr 2021
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Fri 30 Apr 2021 - 05:59 UTC Sat 01 May 2021

ISSUED 21:27 UTC Thu 29 Apr 2021


Broad upper troughing continues to cover much of northern and western Europe on Friday, with the cold pocket over Ireland on Thursday having migrated to England/Wales for Friday. Consequently a reversal of fortunes is expected, with a deeper convective layer in England/Wales and more capping in Ireland resulting in shallower convection here (relative to the previous day). Either way, showers will become more numerous through the day in response to diurnal heating and particularly focussed in areas where low-level convergence is maximised (i.e. just inland from the coast) and dewpoints remain mostly above 0C. This means there could be a relative minima in activity over parts of the Midlands down to the northern Home Counties, although even here a few showers may be possible. 

For the most part, despite 200-400 J/kg CAPE shear will be rather weak beneath the upper low, but on the forward side slightly stronger flow aloft will exist over SE England - albeit most of this will be above the cloud-bearing layer, but could perhaps aid a little with venting. Generally pulse-type convection is expected, and so any lightning will tend to be short-lived/isolated per individual cells (risk in any one location around 10-15%, greatest over S Wales / West Country / SW England). Small hail is likely in several showers (potentially carpeting roads in hail and causing locally icy conditions), and the slack surface flow with enhanced convergence could encourage a couple of funnel clouds to develop.