UK floods

[tich]

300mm in 1 hour, somewhere in northern England? Was that figure right? (reported on TV1 News last night)

[Manukau heads obs]

no, I think it was in 24 hours

[Michael]

yes i heard 320mm in 1 hour but 24 hours seems plausable.

[Michael]

Found it in the herald Cockermouth 530km NW of London 314.4mm in 24 hours the heaviest rainfall ever recorded in the U.K.

[GraemeWi]

I lived in Cockermouth for a while back in the early 90's, I've been watching footage on the BBC website and the center of town looked to be stuffed. 8 ft of water according to one account. There are heaps of historic buildings and gardens, including Wordsworth's birthplace which is right next to the river.

[Simon Culling]

There has indeed been a large fall of rain in the UK, possibly breaking the record for the greatest fall in a given 24 hour period.

It occured in what is known as the Lake District, in the NW of England, close to the Scottish border. This is an area of lakes and mountains with peaks rising to 3000ft, with a narrow coastal plain - not dissimilar to many parts of New Zealand. It occured at Seathwaite Farm at just 129m above sea level, where the record extends back to 1844. Rainfall figures for the 24 hours ending 0900UTC on the days listed were

17th Nov 38.6mm
18th Nov 60.8mm
19th Nov 142.6mm
20th Nov 246.6mm subject to confirmation from the Met Office/Environment Agency

The greatest fall in any given 24 hour period was stated to be 316.4mm for the 24 hours up to 2400 UTC on thursday 19th Nov ie the full day. In the 46 hours from 2000 UTC on wednesday 18th to 0600 UTC on friday 20th (ie 34 hours) a total of 377.8mm fell.

[Simon Culling]

This rainfall event was caused by a classic 'seeder/feeder' situation that remained in place for a couple of days.

A stalled front lying SW-NE just to the north of Cumbria (the county in which the Lake District is located) over this period provided the rain bearing cloud, and a strong feed of warm air on the south side of the front kept the supply of moisture going. The result was a long period of steady rain over the area, enhanced by orographic lift. It is estimated that as much as 50% more rain fell over the higher ground, which reaches up to 3000ft or 900m.

These events are not uncommon on the west side of the UK, especially over the Welsh, Cumbrian and Scottish hills and mountains, but the magnitude of this event is certainly greater than normal, and it was somewhat longer lasting.

The resulting flooding has been devastating for those involved. More details at this link. Today, Sunday, structural engineers have begun inspecting the 1800 bridges in the area as a number have collapsed, and others are in danger of doing so.

http://news.bbc.co.uk/1/hi/england/cumbria/8370692.stm

[Simon Culling]

A further link to the Met Office site gives a few more facts + figures

http://metoffice.gov.uk/corporate/press ... 91123.html

[spwill]

A very interesting weather event , thanks for the info. I have visited the Lake District several times when I was living in the UK for a few years, lovely part of the world.

[GraemeWi]

14 of the 17 pubs in Cockermouth were closed due to the flooding. I'm sure there was something like 23 when I lived there. They are many on the main street virtually next door to each other.

[Simon Culling]

A technical summary of the meteorolgy of this event has been produced by NOAA/Penn State University and can be found at the link below. Its a pity that this was produced in the US only a few days after the event, and our own Met Office has only managed one brief press release. Correct me if I am wrong, but you guys have the same misgivings about your own met service as we do in England about ours.

http://nws.met.psu.edu/severe/2009/20Nov2009.pdf

[NZstorm]

The UK is quite exposed to moisture and its a wonder the exceptional rainfall events don't happen more often. I will read the PDF with interest, thanks.

USA seems to be a fairly unique country regarding access to meteorological information. NZ is in a similar position to the UK with only limited access to the observational data such as radar, surface obs etc. I believe the UK Met Office is an arm of Ministry of Defence, hence problems with limited access.

[Simon Culling]

Steven, you are correct about the ownership of the Met Office. It is what is known as a Government Trading Fund within the Ministry of Defence, and now has a commercial arm. In the year to March 2009 its turnover was £184.4m, of which £97.1m was stated as having been derived from the MoD.

It has become a little more open with regard to providing data such as radar and hourly observations from over 100 stations, but appears reluctant to release climate data from the 500+ stations that it recieves data from, many of which are voluntary. I would have to pay for that data if I wanted it, or travel to its library in Exeter and look each one up myself. Hopefully in the future it will make such a valuable resource, which is digitised, more freely available, but that might be more of a hope than reality. In NZ you do have NIWA, which releases such data on a monthly basis.

Here is another link for the Cumbrian floods, giving a lot more detailed information on the rainfall figures.

http://www.metoffice.gov.uk/climate/uk/ ... index.html