Cambridgeshire Floods

[Coast]

Cambridgeshire saw a month's worth of rainfall in just one night on Sunday 21st October 2001. Cambridge had its wettest day for over 100 years with 87 mm of rainfall on the 21st and a total of 94 mm over the following 4 days

It caused widespread flooding with a number of people having to be evacuated from their houses.

14th to 24th Complex low pressure was centred to the west then south-west of the UK, this brought mostly warm and unsettled weather with plenty of rain and showers on most days apart from the 16th which was mainly dry. From the 19th a number of active low centres and associated fronts crossed the region, bringing more bands of rain and showers often heavy with thunder. Overnight 19th/20th a swathe of rain gave 50 mm in 4 hours at Hereford, with 26 mm falling in one hour. Another disturbance hesitated over East Anglia on the 21st depositing 90 mm at Cambridge with severe local flooding in Cambridgeshire.

www.metoffice.gov.uk/

Frank King's readings of flood levels at Gough Way, Bin Brook:

In most regions, October 2001 was dominated by the passage of low pressure systems, frontal rainfall was plentiful and dry interludes were of very limited duration. Several notably wet spells were of particular hydrological importance. Many localities across the UK registered > 20 mm on the 7th (e.g. Preston 45 mm, Herstmonceux 43 mm) and the three days beginning on the 19th were even wetter. A significant proportion of East Anglia reported around the monthly average rainfall in this episode. Some rainfall totals were exceptional: Cambridge registered 90.4 mm in 18 hours (return period > 100 yrs) and Clavering (Essex) 62.6 in 15 hours. At month-end, a 177 mm 48-hour total was reported for Lochcarron (Highland Region). October rainfall was below average in the western fringes of the UK only; parts of Northern Ireland recorded 80% of the 1961-90 average. Rainfall totals exceeded 150% of average across much of Scotland whilst parts of the English lowlands exceeded 200%. Great Britain registered its third wettest October in the last 25 years (but 2000 and 1998 were much wetter). Regional three-month rainfall totals are mostly within the normal range but notably high across the English lowlands - adding to a cluster of exceptionally wet August-October periods since 1997. Longer term rainfall accumulations, which moderated over the late spring and summer, are again exceptional across much of E&W. The Sept 2000-Oct 2001 total established (marginally) a new 14-month maxima in the 235-year E&W rainfall series

www.nerc-wallingford.ac.uk