The 74-year-old man, who has not been named, was blown into the River Almond at Cramond, Edinburgh, as winds gusted at up to 94mph in Scotland. The ferocity of the storm came close to matching the 104mph of 26 December, the worst blast across south-west Scotland for 30 years.
In Ireland, rescue workers were continuing to search along the west Cork coastline for a German couple who disappeared on New Year's Eve during severe weather. Police fear they may have been swept into the sea while out walking.
A police spokesman said that hopes of finding the 33-year-old man and his 21-year-old companion alive were fading but added that the search was likely to continue for a few more days.
In Britain, two people have already died in the bitter weather and dozens of sailors had to be rescued at the weekend because of high winds.
Forecasters said high winds would die down and be followed by heavy rain in many parts of the country. The Environment Agency warned that rivers in the Midlands were particularly at risk, with belts of heavy rain sweeping in from the south. The Met Office predicted more than two inches of rain for some areas in prolonged showers that will swell rivers to breaking point and flood roads.
Amber flood warnings were issued for the River Severn at Gloucester, the River Leam in Warwickshire and the Avon near Rugby.
There were less serious yellow alerts on rivers in East Anglia, the Midlands, the South and South-west and on the River Dyfi and the Wye in Wales.
ScottishPower estimated about 18,000 customers were without electricity, including many who were cut off for days after Boxing Day. Lockerbie, in Dumfries and Galloway, suffered as 20 oak trees crashed across cables.
A spokeswoman for ScottishPower praised the work of overhead linesmen, some of whom travelled from companies south of the border to restore supplies and had not seen their families for more than a week.
In Northern Ireland, about 1,000 people were thought to be without power, and a further 1,000 who had been given temporary electricity after last week's storms had their power turned off again for repairs.
A spokeswoman for Northern Ireland Electricity said: "As fast as we get more people back on we have others going off again because of the severe weather."
Motorists were warned by police not to venture out unless absolutely necessary as driving snow created blizzards. The M8 through Glasgow was closed after two lorries were blown over and most west coast ferry services were suspended in the wild weather. Fallen trees also halted all services on the East Coast main railway line.
The Forth and Tay Bridges were closed to high-sided vehicles, caravans and cyclists. Many island sailings by Scottish ferry operator Caledonian MacBrayne were suspended, as were services to Northern Ireland from Stranraer.
The Met Office said the weather showed no signs of settling down. "The wind is dying down but there will be heavy rain and we have issued weather warnings for hilly areas which will be seeing prolonged rain over the next few days."Reuse content