Convective Outlook: Sat 10 Nov 2018
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sat 10 Nov 2018 - 05:59 UTC Sun 11 Nov 2018

ISSUED 21:46 UTC Fri 09 Nov 2018


Atlantic upper low slowly drifts towards western Ireland during Saturday, maintaining a feed of cold mid-levels atop warm seas around the British Isles, steepening lapse rates and generating 400-800 J/kg CAPE. Numerous showers are likely over open water, these then moving inland to exposed southern and western areas. Organised troughs / occlusions will push showers well-inland at times, and where such features become aligned with the steering flow may result in consecutive showers training over similar areas and hence the potential for localised surface water flooding - particularly southern coastal counties of England, but such convergence lines may extend well-inland too.

Forecast profiles look rather saturated at times, which combined with limited shear may reduce the lightning potential somewhat. Nonetheless, a low-end SLGT has been issued for S / SE England and adjacent English Channel for sporadic lightning at various times during this forecast period. Some lightning also seems likely over the Celtic Sea, and close to the coasts of SW England and S + W Wales - this area may require an upgrade to SLGT if confidence on coverage improves. In either case, hail up to 1.5cm in diameter and gusty winds will be possible from the most intense cores.