Amber warning of rain, 16-17 November 2010

The example below details an event that happened in Cornwall. It would have generated an amber warning of rain with the new warning service.

Rain Warning Amber Weather situation on 17 November 2010

Weather

A deep area of low pressure in the Atlantic swept bands of heavy rain across much of south-west Britain on 16 and 17 November 2010. The heaviest rain occurred overnight in Cornwall. The rain was particularly intense between 0400 and 0700 GMT on 17 November.

Rainfall totals for the period 2100 UTC on 16 November to 0900 UTC on 17 November included:

Heligan (near Mevagissey)

60.8mm

Stoke Clether (Bodmin Moor)

55.0mm

Cardinham, Bodmin

50.2mm

Luxulyan

49.0mm

Bastreet

45.8mm

Bodmin

45.0mm

The very intense rainfall resulted in rapid surface water run-off. The short, steep, rapidly responding nature of Cornwall's river catchments make them particularly susceptible to flooding from this type of intense rainfall.

Impacts

A flooded street A flooded street

  • One hundred houses in the village of Mevagissey were flooded.
  • Roads in the immediate area were flooded and vehicles were stranded.
  • Train services in and out of the county were disrupted by landslides.
  • Schools were closed and the county's main trunk roads were closed for several hours.
  • There were 25 vehicles that required recovery from flood water.
  • An emergency centre was opened by Cornwall county council at Polkyth Leisure Centre in St Austell.
  • The Eden Project also suffered from flooding.

Warning Assessment

Based on the new warning system the following assessments would have been made:

  • Likelihood - medium
  • Impact - high

This would have resulted in a amber warning for rain:

Amber Warning

Last updated: 26 March 2012