Convective Outlook: Sat 28 Jul 2018
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sat 28 Jul 2018 - 05:59 UTC Sun 29 Jul 2018

ISSUED 22:34 UTC Fri 27 Jul 2018

ISSUED BY: Dan

A sharp upper trough will pivot northeastwards across central and southern Britain on Saturday, providing strong forced ascent along a cold front. This combined with a few hundred J/kg CAPE will allow convective elements to develop at times along the cold front, which will be located from The Wirral to West Sussex at the beginning of this forecast period. Some sporadic lightning and strong, gusty winds will be possible as this band of showery rain continues to pivot northeastwards, while fragmenting, through the morning. An isolated tornado cannot be ruled out. A low-end SLGT covers this risk.


By the afternoon, diurnal heating of the post-frontal airmass and cool air aloft beneath the upper trough will lead to several hundred J/kg CAPE, with scattered showers expected to develop, some containing isolated to sporadic lightning. A low-end SLGT has been issued to cover the broad risk area, but many places within the SLGT could remain lightning-free. Some hail and gusty winds will be possible with the most intense showers/storms.

Across northern and eastern Scotland, including the Northern Isles, remnants of the old instability plume will continue to destabilise with periods of heavy rain, with embedded elevated thunderstorm activity likely. The SLGT also covers this risk.