The AA warned drivers to take extra care during the heavy downpours forecast for Wednesday and Thursday.

A spokesman said the worst of the weather could coincide with tomorrow evening's rush hour.

Motorists should be particularly wary of spray from other vehicles reducing visibility and the possibility of aquaplaning on roads slick with water. Other dangers include fallen debris caused by the high winds.

Drivers should also take care not to travel too quickly through floodwater, as this can blow the engine.

AA Patrol of the Year Steve Neath advised: ''It can take just an egg cupful of water in the combustion chamber to wreck an engine.

''Water doesn't compress and the piston in effect hits a wall, bending or breaking a con rod and possibly shattering the engine block.''.