Update 2.49pm:Storm Doris has claimed its first victim after a woman died when she was hit by a piece of roof the "size of a coffee table".
The pedestrian was confirmed dead at the scene outside Starbucks in Wolverhampton city centre after suffering "very serious head injuries", West Midlands Ambulance Service said.
Rebecca Davis, a 40-year-old teacher from Wolverhampton, walked past shortly after the incident at around midday and saw a woman receiving CPR.
She said the woman - who looked to be aged "between 20 and 30" - appeared to have been hit by something resembling a piece of roof which had fallen off a building nearby.
"I think the wind broke it and caused it to fall. I don't know if it was hit by something else or just the wind did it," she told the Press Association.
She said that while the woman had been hit "right outside Starbucks", it was unclear if the debris had fallen from the coffee shop or from a nearby building.
"I don't think anyone else was hurt. It was a big piece about the size of a coffee table but I think it just hit her," Mrs Davis said.
Update 1.40pm: A woman has died in Wolverhampton city centre after being hit by debris caused by Storm Doris.
She was confirmed dead at the scene outside Starbucks after suffering from "very serious head injuries", West Midlands Ambulance Service said.
West Midlands Police said officers were called to a "serious incident" in Dudley Street at around 11.50am.
Earlier: Storm Doris wreaked havoc as she embarked on a destructive path across the UK - bringing gusts of almost 95mph.
Branded a "weather bomb" by the UK's Met Office, Doris brought down trees, forced the closure of the port of Liverpool and caused the cancellation of Coronation Street filming.
A top wind speed of 94mph was recorded in Capel Curig, North Wales, as Doris rolled in, with 82mph also clocked in Aberdaron, North Wales, the Met Office said.
Senior meteorologist Greg Dewhurst said the storm will bring "very strong winds and gales", and that the centre of Doris will "track out to the North Sea at around lunchtime".
He added: "The whole system will still be over the UK, right through the afternoon. The winds then will start to ease from the west through this evening."
Amber warnings predicting strong winds and heavy rain are in place for North Wales, the Midlands, the East and the North West and have been extended to include the London area.
The Met Office said gusts of 60mph-70mph were likely to be seen in affected areas, with 70mph-80mph expected on coasts and hills.
As Doris hit, Peel Ports in Liverpool announced on Twitter that the city's port had been closed due to "100mph gusts of wind".
The company said: "All operations are stood down for the safety of our employees, contractors and customers of the port."
National Rail advised that fallen trees, objects caught in overhead wires, heavy rain, flooding and debris on tracks were causing delays to a number of services across the country.
Highways England also closed the QE2 Bridge over the Thames at Dartford, the Orwell Bridge on the A14 in Suffolk and the M48 Severn Bridge, due to strong winds.
Issuing a weather alert for major roads, the body said high-sided vehicles, caravans and motorbikes were at risk of particularly at risk, and "strongly advised" drivers to avoid travelling on some stretches of road in Yorkshire, the Midlands, the East and the North West.
Outdoor filming for Manchester-based Coronation Street was also brought to a halt as Doris paid a visit to the cobbled set.
A spokeswoman for the ITV soap said affected scenes would be rescheduled.
Cornwall Fire and Rescue Service said crews were called to help free a man trapped when a tree fell on his van on the A374 between Antony and Sheviock.
The service said firefighters used "winches and crash rescue equipment" to release him.
In Scotland the M80 was closed in both directions, owing to snowfall, before it was reopened at around 12pm.
Up to 6in (15cm) of snow is expected across parts of Scotland and north-east England, bringing treacherous, blizzard-like conditions.
Weather warnings have also been upgraded to amber across Scotland's central belt, the Borders, Dumfries and Galloway, Tayside and Fife.
In Aberdeenshire, some schools have been closed due to the weather, while some school transport is not operating.
All school transport in the Borders has been cancelled for the day as heavy and widespread snow is forecast across much of the area.
Ferry services have also been affected by the weather, with Caledonian MacBrayne warning of disruption on some west coast routes.
Elsewhere, the snow gates have been closed in both directions on the Banchory to Fettercairn route, while Traffic Scotland warned of high winds on the Tay Road Bridge and the Erskine Bridge.
Storm Doris was branded a "weather bomb" after the system underwent "explosive cyclogenesis", the Met Office said.
"It has gone through what they call explosive cyclogenesis - so a deepening of 24mb in 24 hours," a spokesman said.
"Storm Doris is still Storm Doris, it does not mean it is necessarily any more severe than we had forecast already."