13 September 2016 – Thunderstorms

[xmetman]

Here is my best guess rainfall accumulations for yesterday between 0900 UTC and midnight. I now use 5 minute data and this has increased the accuracy of my estimates. You can see the south north track of the thunderstorms from when they initially made landfall in Devon and Dorset in the morning before moving up through the west Midlands and curling into northwest England during the evening. The wettest places (09-00) where around the Manchester area with an area of lime green pixels indicating totals of between 32 and 40 mm.

This is a table of 24 hour rainfall totals (06-06) which show even larger totals than those of northwest England occurring at Culdrose and Camborne in the west of Cornwall with over 47 mm at both stations from thunderstorms. Due to Met Office policy, there are currently no SYNOP stations in the Manchester area (population 2.55 million) so you won’t see any totals around the 34.8 mm mark from around there – oh dear, how sad, never mind.

And finally here are the 40,929 lightning flashes that occurred between 0900 and 2300 UTC yesterday over the British Isles courtesy of Blitzortung.

[Richard Dixon]

I noticed that (the excellent) Cloudwater Brewery had a bad flood in Manchester. They're about 10 miles NNW of Woodford so right in the path of that heaviest rainfall. My sister in Knutsford and friend in Poynton both reported armageddon-like scenarios! 

Richard

[Scott Whitehead]

Richard: I know the Met Office has closed a few observing stations but closing Woodford seemed the most senseless, given the lack of equivalents close by

[Martin Rowley [West Moors/East Dorset]]

.... Thanks for that Bruce: good agreement here (West Moors = small red box) with 13.7mm. Hurn kit knocked out (again!) by the power outages around here - but they would have been in the lighter blue zone and somewhere in the lower 20s mm for that storm (with spot high intensity of course) would account for the small-scale flooding experienced.

Martin.