These incredible pictures show how 140mph winds and waves more than 50ft high are lashing Britain as the so-called "weather bomb" strikes.
Thousands of homes are still without power after gales and lightning strikes caused by the weather bomb hit the north of England, Northern Ireland and Scotland overnight with warnings still in place across Britain.
Huge waves battered sea fronts across these areas - and other parts of the country are expected to see snow within the next few days.
The process behind the storm - rapid cyclogenesis - is known colloquially as a "weather bomb" - a storm that intensifies much quicker than normal.
In Blackpool, the waves were so bad they threw waves of foam onto the road by the beach, making it nearly impossible for drivers to see and forcing to slow to a crawling speed to avoid crashing.
During the worst of Wednesday's weather, a fishing vessel had to be escorted to safety off Orkney after it was hit by a wave which smashed windows on the bridge.
The British-registered vessel O Genita, which has a Spanish crew, was escorted to Westray in Orkney by an RNLI lifeboat. None of the 16 crew were injured.
In Scotland, around 27,000 homes in the Western Isles and Skye lost electricity due to lightning strikes yesterday.
Weather bomb batters Britain
Hundreds of engineers worked to restore it overnight but further lightning strikes caused additional disruption and they warned further faults could develop.
Electricity provider SSE said lightning had been the biggest feature of the weather bomb, with more forecast for Thursday.
The mainland has so far survived relatively unscathed, with the northern isles around Scotland worst affected.
High winds also fed a serious fire at a day care centre in Withington, Greater Manchester, which 30 firefighters were fighting at one point on Wednesday night.
There has also been disruption to travel across Scotland with some coastal roads flooded, and ferries and trains cancelled.
A wind speed of 144mph was recorded on the remote St Kilda islands, with gusts of more than 80mph also hitting some low-lying areas.
A Met Office has downgraded its weather warning for the west coast of Scotland, the Highlands and Islands, Orkney, Shetland and Northern Ireland to a yellow - "be aware" - as the gales gradually eased to be replaced by wintry showers bringing snow and ice.
Forecasters said there could be some "significant" snow accumulations in parts of Scotland with the rest of the UK set to see snow over the weekend.
There is an 80% probability of icy conditions and some snow in the North of England between midnight on Friday and Sunday morning, according to the Met Office, which issued a cold weather alert.
The forecasters said: "This weather could increase the health risks to vulnerable patients and disrupt the delivery of services.
"The recent cold and unsettled weather is expected to continue through to the coming weekend. A band of rain, and hill snow in the north, is expected during Thursday night. There is also a risk of some snow down to lower levels at times in eastern and north-eastern parts.
"Rain and snow will clear early on Friday, leaving bright but cold conditions. Brisk winds will exacerbate the cold feel at times. A few wintry showers will follow but any snow accumulations will be mainly restricted to hills."
Network Rail and ScotRail expect full services to be running throughout today.