In Thunder, Lightning and in Rain..
A while before 6am this morning I was woken up by the sound of fairly distant thunder to the West of my flat. I left the windows open – they’ve been open all the time in this hot weather – and dozed while rumblings continued. Just after six there was a terrifically bright flash and an instantaneous bang that set car alarms off in my street; lightning must have struck a building very close. Then the rain arrived. I got up to close the windows against the torrential downpour, at which point I noticed that water was coming in through the ceiling. A further inspection revealed another leak in the cupboard where the boiler lives and another which had water dripping from a light fitting. A frantic half hour with buckets and mops followed, but I had to leave to get to work so I just left buckets under the drips and off I went into the deluge to get soaked.
Here is the map of UK rain at 07:45 am, with Brighton in the thick of it:
I made it up to campus (wet and late); it’s still raining but hopefully will settle down soon. This is certainly turning into a summer of extremes!
Follow @telescoper
In the Dark 
July 28, 2014 at 11:05 am
It is less unusual for water to get in during torrential rain than people think; torrential rain is really quite rare in Britain, and of short duration. Nevertheless it’s not a nice thing and if you live in rental accommodation then it’s important to inform the landlord both to give him the option to plug leaks and to cover yourself.
If you give half of the world’s population a video camera (in a mobile phone) then things that used to be very rarely caught are going to be quite common on YouTube. I greatly enjoy watching close lightning strikes – and what people say. I’m not aware that any light has been shed on ball lightning by the coming of videocam mobile phones, though. (I’m a ball lightning nut and have read up on all the theories.)
There is said to be a gush of rain in the vicinity of lightning strikes (supposing it actually is raining there and then), due I think to dramatic reduction in the electric field that had been holding up electrically charged raindrops against gravity. Does anybody know if this is accurate?
I’m glad that that map shows nothing over Southampton where the Test Match is on.
July 28, 2014 at 12:14 pm
I think what generally happens in such very heavy downpours is that the flood of surface water gets in behind the flashing joining roof sections together. I had the same problem in Nottingham when water ran down the sloped roof against a chimney stack then splashed over the flashing and in through the roof. It’s a big problem for old roofs, with old fashioned lead flashing which degrades over time.
I’m not all that bothered by the dripping water but am concerned that it was coming down through the light fitting in the bedroom…
July 28, 2014 at 12:31 pm
I’m not disputing it, but how does lead degrade?
July 28, 2014 at 12:41 pm
Lead doesn’t suffer from oxidation problems (actually it does a bit, but the oxide tends to form a protective layer on the surface). The problem tends to arise with the sheets of leading from which the flashing is made expanding and/or contracting with changes in temperature and thus working free from the fixing, or sometimes tearing if it has been fixed too strongly, which allows water to get in behind.
August 5, 2014 at 12:04 am
Update – I just checked Wikipedia on ball lightning for the first time in more than a year and there is news! The phenomenon was captured on video at the point of a lightning strike in 2012 and the analysis appeared in PRL in January this year. A spectral analyser was pointed there too. The results give support to the vaporised silicon hypothesis, the silicon coming from the soil. See
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.035001
August 8, 2014 at 2:09 pm
Too bad they didn’t call the paper “Goodness gracious, Great balls of fire”.