There are now 18 flood warnings and 198 flood alerts issued across England, the Environment Agency said.

The warnings cover the North Sea at Scarborough, Lower Avon at Christchurch, Upper Frome at Maiden Newton and the Aire, Dart, Dee, Lemon, Ouse, Severn, Teign, Washford and Yarty rivers.

A body has been found after an extensive search operation off the coast of Kent. Lifeboats and the coastguard helicopter had been scouring the sea near Margate Harbour after reports of a man overboard, HM Coastguard said.

HMS Westminster was also believed to have responded to a relay call, and is in the area, according to ship-tracking data. The search operation came as communities across the UK braced themselves for the arrival of Storm Dennis on Sunday, just one week after Storm Ciara battered the nation.

The government said it will use “all means” available to help flood-hit communities after the army was sent in to help locals in West Yorkshire prepare for Storm Dennis.

A deployment of 75 soldiers from the 4th Battalion Royal Regiment of Scotland was supporting the Environment Agency’s efforts in Calderdale, which is expecting floods for the second weekend in a row.

A further 70 reservists from the 4th Battalion the Yorkshire Regiment were sent to help.

The defence secretary, Ben Wallace, said: “Our armed forces are always ready to support local authorities and communities whenever they need it.

“The rapid response of the army today will help with provision of flood relief to local communities in West Yorkshire.

“The government won’t hesitate to use all means at its disposal to mitigate the effects of Storm Dennis.”

The Met Office said the main areas of concern on Saturday are north and south-west England and Wales, with the south-east bearing the brunt more on Sunday.

At just after 1pm on Saturday, there were 17 flood warnings – meaning flooding is “expected” – and 179 flood alerts – meaning flooding is possible – across the country.

John Curtin, executive director of flood and coastal risk management at the Environment Agency, has posted a timeline on when Storm Dennis is expected to hit the UK.

Animal shelter Battersea has advised pet owners to check their fences and gates before letting their dogs out in the garden and consider keeping them indoors until the storm passes.

Emergency services are warning of dangerous driving conditions.

North Wales Police said very high winds had led to debris and branches falling off trees while Cornwall Fire and Rescue Service said it had rescued a motorist from a car stuck in flood water in the Liskeard area.

Carlisle East Fire Station has advised motorists to avoid driving through flood water.

Two drop-in centres have been opened for people affected by flooding in Wakefield, West Yorkshire.

The weather has played havoc with sporting fixtures scheduled for today.

Nine games have already been called off in the National League.

Rochdale against Tranmere is also off in League One owing to a waterlogged pitch.

CrossCountry rail passengers have been advised that some journeys will take longer because of speed restrictions.

The Met Office has updated its advice on the amber warnings issued. Amber means it is quite likely that adverse weather will affect people, possibly including travel delays, road and rail closures and power cuts.