Convective Outlook: Thu 31 Aug 2017
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Thu 31 Aug 2017 - 05:59 UTC Fri 01 Sep 2017

ISSUED 19:50 UTC Wed 30 Aug 2017

ISSUED BY: Dan

Upper trough and associated cold pool / steep lapse rates will drift gradually southeastwards across the British Isles, generating several hundred Jkg-1 CAPE. Showers will be ongoing over western areas at the beginning of the forecast period, with several high-res models suggesting a cluster of thunderstorms possible over N Wales / NW England and adjacent Irish Sea during the morning, lightning activity then becoming more widespread through the day as showers develop more widely. Late arrival of upper trough means showers may be late to arrive / develop over East Anglia and SE England, and hence linger for quite some time during the evening.


In general, convection a little more limited in depth across southern areas than farther north, hence a better aerial coverage of lightning is more likely over northern England. There may also be an uptick in activity over the English Channel / Channel Islands during the early hours of Friday, hence a low-end SLGT issued here.

Hail up to 1.5cm in diameter will be possible with the strongest cells, allowing the the risk of some localised surface water issues given slow storm motion. A few funnel clouds cannot be ruled out.