Thunderstorm: May 29th 2018

Posts about thunderstorms are usually few and far between – the average number of thunderstorms in this part of the UK in a summer month (July) is just 3.5.

So experiencing four in four days must be very rare; the record for thunderstorms in a month is 12 in June 1982 though I’ve no idea how many of these were on consecutive days.

While the storms over the weekend were all about lightning this one was all about rain and loud thunder. Tuesday, May 29th, started cloudy and dull with some light rain. I was expecting some rain but it lingered and became heavier at 11.30am before turning torrential at 1pm, going against forecasts from BBC and Met Office – the trough was a lot further north than modelled. I pointed this out to the UKMO to be told that a yellow warning was in place for the whole SE region.

29th rain
The bulk of the rain fell between 1pm and 2pm
Screen Shot 2018-05-30 at 01.13.12
A marked drop in pressure coincided with a bright flash of lightning that was almost instantly followed by thunder that was as loud as cannon fire

Some 26.5mm fell in just over two hours bringing lots of surface water and flash floods around Leyton and Walthamstow. At 1pm, while driving in this area, a bright flash was quickly followed by cannon-like thunder. A further fall in the early hours brought the 09-09 total rainfall to 29.8mm, the 5th greatest May fall since 1959.

With the storm the previous evening the 48hr rainfall total was 40mm!

In the neighbouring borough of Barking and Dagenham it was reported that lightning struck a chimney which caused a fire in a terraced house in Rush Green at 2pm.

Local media pick up the story here, here and here.

image
The position of the storm around the time of the loudest thunder
South acess
South Access Road in Walthamstow suffered flash flooding as drains failed to cope with the volume of rainfall
trough
The trough on this FAX chart suggested the heaviest rain would be slightly further south than it was

rain1315

warn
The Met Office forecast for Tuesday shows how useless auto generated apps can be, the 10-20% risk of rain between 1300-1400 contradicts the yellow warning
cum
Posted by Simon Cardy: “The large mature Cumulonimbus clouds over SE England (outlined purple on the map) are producing frequent lightning, very loud thunder and heavy rain. (credit: EUMETSAT).”

 

 

Advertisements

One thought on “Thunderstorm: May 29th 2018”

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.