Convective Outlook: Sat 21 May 2016
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Sat 21 May 2016 - 05:59 UTC Sun 22 May 2016

ISSUED 18:57 UTC Sat 21 May 2016

ISSUED BY: Chris

UPDATE: To include numerous thunderstorms crossing the Channel, likely affect the Kent and East Sussex coast, and southeast England. Uncertainty still remains on if these will impact the East Anglian coastline into the evening. 

Scattered showers are likely to turn heavy and thundery across Ireland and into parts of Britain during the afternoon on Saturday. Cold air aloft and afternoon surface heating will allow Surface to 500mb lapse rates to reaching into the lower 40s across Ireland, where the most frequent and widespread lightning is likely to occur during the afternoon. Lapse rates are less across Britain, but CAPE values of 300-500j/kg could allow for a few showers to turn thundery there in the afternoon. 

Saturday evening and overnight a plume of unstable air will move out of France pushing an area of showers and thunderstorms northeastwards. There is still a lot of uncertainty about the track of these storms, and it appears most of them will stay offshore, however it is close enough to include a risk. It should be noted that if these storms do move across Kent and up the east coast of East Anglia they would likely require an upgrade to SLGT as they could be quite electrically active. The situation will be monitored later this afternoon and through the early evening.