Convective Outlook: Fri 30 Jun 2017 |
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What do these risk levels mean? |
Convective Outlook
VALID 06:00 UTC Fri 30 Jun 2017 - 05:59 UTC Sat 01 Jul 2017
ISSUED 18:20 UTC Thu 29 Jun 2017
br> br>ISSUED BY: Dan
Upper vortex will be centred over France on Friday, with cool air aloft providing an environment with reasonably steep mid-level lapse rates - the best lapse rates mainly over France, but just clipping SE England. A decaying band of showers over the English Channel will pivot inland across SE England during the morning, probably no more than a marked zone of wind convergence, but this then providing the focus for scattered showers and perhaps a few thunderstorms to develop inland in response to diurnal heating.
Slow storm motion will bring the risk of some localised flash flooding, with scope for 20-30mm to fall in a short space of time. The area most at risk is Kent and East Sussex, though if cloud breaks are a little more widespread to allow sufficient insolation, then the risk could extend as far west as Exeter and perhaps into Essex / south Hertfordshire. Slack flow and low-level convergence may allow a few waterspouts / tornadoes to occur.