Download the July 2012 flooding casestudy (PDF, 1 MB) - Met Office

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Education case study
Flooding 6 and 7 July 2012
Persistent rain brought flooding to many parts of the UK during the first weekend
of July. The impacts were numerous, ranging from flooded transport networks to
disrupted sporting events.
Meteorological situation
Image 1 below is the weather chart for 6am on 7 July 2012. Low pressure was centred over
Cornwall. A cold front affected Northern Ireland and Southern Scotland. A cold front represents
a boundary between warm and cold air with the warm air ahead of the cold front and the cold
air behind it.
An occluded front affected South West England. On a weather chart an occluded front represents
where a cold front has caught up with a warm front.

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Education case study
Flooding 6 and 7 July 2012
Met Office forecasters look at weather radar images to show where rain is falling. Brighter colours
indicate heavier rainfall. Image 2 below shows the rainfall radar image for the same time as the
weather chart on the previous page. The bands of rain correspond with the positions of the
weather fronts.
East Devon was particularly affected by flooding. June and early July had been particularly
wet so the flooding was worsened by already saturated ground. Between 6pm on 6 July and
12 midday on 7 July South and East Devon typically received 40–50 mm of rain. This figure
is roughly what would be received in an average July. Some rain gauges in East Devon which
belong to the Environment Agency measured around 100 mm of rainfall in 33 hours, that’s twice
the July average rainfall.

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Education case study
Flooding 6 and 7 July 2012
Image 3 below shows rainfall figures (mm) for the 24 hour period of 6 July.
56.6 mm was recorded at Emley Moor with 52.6 mm at Ryhill (both in West Yorkshire).
Each of these figures exceeded the July average.

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Education case study
Flooding 6 and 7 July 2012
Image 4 below gives more detail for Southern England for the period 6pm on 6 July to
12 midday on 7 July.
53.8 mm of rain was recorded at Dunkeswell, Devon, 45.2 mm at Portland, Dorset
and 43.6 mm at Exeter Airport, Devon.

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Education case study
Flooding 6 and 7 July 2012
Impacts
Image 5 below typifies what some people experienced between 6 and 7 July 2012.
Many parts of the UK were affected by the flooding. At Silverstone on the Northamptonshire/
Buckinghamshire border, thousands of Formula 1 fans were turned away from the qualifying
session on 7 July due to waterlogged car parks. In the Scottish Borders the A1 was affected by
flooding and there were land slips at Lyme Regis in Dorset and at Sidmouth in Devon.
The Met Office issued a red warning (meaning take action) for South West England.
The Environment Agency issued two severe flood warnings for South West England in addition
to over 200 warnings and alerts for England and Wales. The Scottish Environment Protection
Agency had 13 flood warnings in place for Edinburgh, the Lothians and Borders.
East Coast rail services were affected for the second time in a week and there were disruptions
to rail services between Glasgow and Edinburgh. In Edinburgh a festival was cancelled.
Many areas of the UK rely heavily on tourism and July is normally a very busy time.
During particularly wet spells people often cancel bookings and stay at home meaning the
rainfall had economic impacts beyond the physical damage to the flooded cars and houses.
If there was one positive to be taken from this rainfall episode it was that the hose pipe ban
affecting South East England was finally lifted.
Further information
www.bbc.co.uk/news/uk-18722054
www.guardian.co.uk/uk/2012/jul/08/uk-floods-forecast-homes-underwater
www.bbc.co.uk/news/uk-scotland-18752725
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