Convective Outlook: Fri 26 May 2017
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Convective Outlook

VALID 06:00 UTC Fri 26 May 2017 - 05:59 UTC Sat 27 May 2017

ISSUED 09:12 UTC Fri 26 May 2017


A large-scale upper trough will approach Ireland from the west during Friday and in combination with a ridge to the east, will help to pull in a moist, unstable airmass from the south. A pre-cold frontal trough is expected to move into western Ireland during the afternoon and in combination with daytime heating and SBCAPE of 500-800j/kg should be enough generate surface based thunderstorms that could quickly become quite electrically active (initiation of thunderstorms in the Irish slight area is expected between 15-16z). Otherwise more isolated embedded thunderstorms may cross Ireland from west to east as the cold front moves through during Friday evening. 

Overnight the cold front will continue to progress eastwards and an area of midlevel instability will spread out of France and across the Channel into southern/southwestern England towards the end of the night.  MUCAPE of 600-800j/kg will move into the slight risk region in Britain towards the end of the night. Mid-level thunderstorms are expected to develop in the vicinity of Devon and Dorset around 02-03z on Saturday morning. This area of mid-level thunderstorms will continue NNW into Wales through the end of the night and into Saturday morning. 

An outlook for Saturday-daytime (post 06z) will be issued sometime on Friday.