Convective Outlook: Fri 30 Jul 2021
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Fri 30 Jul 2021 - 05:59 UTC Sat 31 Jul 2021

ISSUED 05:34 UTC Fri 30 Jul 2021

ISSUED BY: Chris

An unusually deep area of low pressure for late July will spread east northeastwards across Wales and southern and central England on Friday bringing outbreaks of rain with embedded showers and perhaps a few thunderstorms. The main hazards from this low will be strong winds on its southern flank, particularly along the south coast of Wales and southern England along with some prolonged and at times, heavy rain with the risk of localised flooding. 


Isolated lightning strikes cannot be ruled out, particularly near low centre as it tracks eastward. However, the greatest chance of lightning will be across parts of the E Mids and into E Eng and northern parts of E Anglia during the afternoon and early evening. A low-end SLGT risk has been issued for this area to note the slightly increased risk in this area. 

CAPE values of around 500 J/kg will develop across the SLGT risk area during the afternoon with ELTs approaching -30C, and along with strong PVA across the region on the leading edge of the low, could help to develop some deeper convection capable of producing lightning. Overall shear is quite weak near the centre of the low where convection is deepest, however low-level convergence combined with low-level CAPE could help to produce a few funnels or perhaps a weak tornado in the SLGT area.