Winds of more than 100mph have left thousands of homes without power, buildings damaged and transport disrupted as Storm Gertrude sweeps the country.
A man in Edinburgh is being treated in hospital after he was struck by flying debris in the Pinkhill area of the Scottish capital. He suffered head injuries but is said to be in a stable condition in Edinburgh Royal infirmary.
A rare red Met Office alert is in place for Orkney and Shetland with dangerous conditions and winds of 100mph expected throughout Friday.
Many other regions have yellow and amber warnings for strong winds, heavy rain, snow and ice as the extreme weather continues to batter the British Isles.
A gust of 105mph was recorded in Lerwick, Shetland at 2pm with other winds above 80mph battering Inverbervie in Aberdeenshire and Orlock Head in Northern Ireland as the storm moves north east.
Winds reached 144mph in the Cairngorm mountains and nacreous clouds, which the Met Office said are usually seen in polar regions, were also spotted in the north-east of Scotland.
Forecasters said: "Winds are expected to widely gust 60-70mph, possibly up to 80mph along exposed coasts and over hills.
"Storm-force west to south-westerly winds are expected to develop across Shetland during Friday. Frequent gusts of 80-90mph are expected, with gusts of around 100mph likely for a time this afternoon.
"Expect dangerous conditions including structural damage and debris, disruption to power supplies and widespread disruption to transport, and take action to secure loose items."
Around 10,000 homes were left without power in Scotland and Northern Ireland with Scottish Hydro saying repairs in Aberdeenshire, Perthshire and the Western Isles are dependant on the weather.
Other properties were damaged with flats evacuated in Clydebank when scaffolding was blown through a roof.
A number of people were injured on the A96 in Huntly when a lorry was blown over on to a car.
The Scottish Fire and Rescue Service said the people in the car managed to get themselves clear but the lorry driver had to be freed by firefighters. The occupants of both vehicles suffered a variety of injuries but none are believed to be life-threatening.
Prime Minister David Cameron was caught up in the disruption on his way to Belgium for EU talks.
Speaking on BBC Good Morning Scotland, he said: "My first challenge is to get to Brussels as with hurricane (sic) Gertrude I've already had a flight problem so I'm racing across Scotland at the moment to get to Edinburgh Airport but I hope I will make it."
Drivers also had to avoid a trampoline blown on to the Newtonhill flyover near the A90 in Aberdeen at around 6am.
All schools in the Northern and Western Isles have been closed with more following on the mainland throughout the day.
Oxgangs Primary in Edinburgh was forced to close after part of a wall was blow off.
Train and ferry services are also vastly reduced.
A succession of storms since December has seen widespread flooding and major disruption to travel, with the latest front expected to continue through the weekend.
The Scottish Environment Protection Agency (Sepa) has almost 40 flood warnings in place covering Ayrshire, Tayside, west central Scotland and the Highlands, while south of the border the Environment Agency is urging communities in southern England and parts of the North to stay alert to the risk of renewed flooding over the weekend.
The River Ouse in North Yorkshire and the Severn at Shrewsbury are expected to be particularly high.
Neil Davies, national flood duty manager at the Environment Agency, said: "More wet weather this weekend means that communities in parts of southern England and the North should stay alert to the potential for further flooding.
"Teams from the Environment Agency will be out over the weekend continuing their work to check and repair flood defences as well as clearing watercourses and offering help and advice to communities still recovering from the impacts of flooding over Christmas.
"Strong winds combined with high tides could lead to large waves and spray especially for the Yorkshire coast and parts of southern and western coasts. We advise anyone near coastal paths and promenades to take extra care and to avoid the temptation to go 'wave watching'."
P&O Ferries said the Pride of Hull ferry, from Rotterdam, had been unable to berth this morning due to "extreme weather conditions".
A spokesman added the ferry had experienced winds of 60 knots this morning, which he described as "rare".