Tens of thousands of homes are without power as two men have died in road collisions during Storm Bert.

Winds of up to 70mph are set to batter coastal areas and, as temperatures rise on Saturday, melting snow and heavy rain are causing flooding, with UK power chiefs saying the worst of the impact is yet to come.

Hampshire Police said a man died after a tree fell onto a car on the A34 southbound near Winchester on Saturday morning.

A man in his 60s who was driving a black Mercedes was confirmed dead at the scene on the A34 southbound carriageway, between Kings Worthy and Winnall, and the force is investigating whether the incident was linked to the weather.

Meanwhile in West Yorkshire, a 34-year-old man from Bradford was killed after a car collided with a wall in Shipley.

Police were called at 12.59am and the man was pronounced dead at the scene

Officers continue to investigate the cause but it is understood the road was not icy at the time of the incident.

Tens of thousands of homes have been without power, with 4,000 homes affected in the Midlands, south-west England and South Wales and 27,000 customers affected in the North East, Yorkshire and northern Lincolnshire.

Ross Easton, of Energy Networks Association (ENA) – which represents the UK’s power network operators, said: “There are a few localised weather-related power cuts in parts of Britain this morning. However, for most parts of the country the severe weather hasn’t yet had a significant impact.

“Forecasters are describing this as a ‘multi-hazard event’ with the worst of the weather yet to arrive, and so our members have extra engineers and contact centre teams available, and control rooms are monitoring the storm closely as it develops.”

More than 100 flood alerts are in place across the UK.

The Environment Agency (EA) has issued more than a dozen red warnings meaning flooding is expected in the north west of England, including for the M61 between Manchester and Preston.

The Met Office forecasts heavy rain developing overnight and into Sunday for south-west and southern England, stretching from Oxford to Truro.

The yellow warning is in place from 6am on Saturday until 11.45pm on Sunday and up to 70mm of rain could fall during this time.

There is a chance that some places over Dartmoor could see 100-150mm of rainfall, the national weather service said.

Strong winds are set to cause “dangerous coastal conditions”, the Met Office said, and a yellow wind warning is in place until 9pm on Sunday for southern England and parts of Wales.

The strongest gust so far during the storm was 82mph recorded in Capel Curig, north Wales.