Hong Kong's Christmas travellers fly into ice storm as blizzards sweep across the US and Canada
Blizzards in the US and Canada that have left major cities snowbound and homes without power threaten holiday plans of thousands
Danny Lee and Agencies
Thousands of travellers face Christmas misery as storms wreak havoc at popular holiday destinations for Hongkongers.
A major snow and ice storm moving across central and eastern Canada has left nearly half a million homes without power.
Major cities including Toronto and Montreal have been hit after power lines buckled under the strain.
"This is truly one of the worst ice storms we've seen," Toronto Hydro Chief Executive Officer Anthony Haines said.
But Toronto Mayor Rob Ford said it was too early to declare a state of emergency.
"If it gets really bad in the next 24 hours we could have a state of emergency, but we're not in that situation quite yet," he said.
Canadian Prime Minister Stephen Harper tweeted: "Thoughts are with those without power due to the ice storm. Please stay safe."
In the United States, snow and ice knocked out power to 400,000 homes and businesses in Michigan, upstate New York and northern New England.
At least nine deaths were blamed on the storm.
They included five killed in flooding in Kentucky, three traffic deaths on icy roads in Oklahoma and a woman who died after a tornado with winds of 209km/h struck in Arkansas.
Five died in eastern Canada in road accidents blamed on the severe weather.
Video: Ice storm hits Canada, leaving thousands in the dark
Meanwhile, amber weather warnings, the second highest alert, were issued in Britain as a major storm swept in packing winds of up to 112km/h in the worst affected areas - which included Heathrow Airport - and dumping up to 38mm of rain.
Heathrow advised people to check with their airline before travelling as the weather "may cause schedule disruption".
The Met Office warned that flooding was possible in southwest England as heavy rain fell on already saturated ground. Rail operators were bracing for disruption, putting hundreds of engineers on standby to help clear potential debris from tracks.
In the US, as of mid-afternoon on Sunday, more than 700 flights had been cancelled and more than 11,000 delayed, according to aviation tracking website FlightAware.com No Hong Kong flights to or from New York's John F. Kennedy airport were disrupted or delayed.
More than 400 flights were cancelled at Toronto's Pearson International Airport, with dozens more scrapped in Ottawa and Montreal.
The storm left up to 30mm of ice in the Toronto area and may dump as much as 10mm of snow in southeastern Quebec today, Environment Canada said.
Two Hong Kong-bound flights, operated by Air Canada (AC015) and Cathay Pacific (CX825) that left Toronto on Sunday, arrived five hours late.
Robin Hutchinson landed yesterday in Toronto from Hong Kong in the middle of the storm.
"15hr flight from Hong Kong, come home to no power & ice storm in #TO [Toronto]. Welcome home to me I suppose! Ice covered trees are kinda pretty tho," she tweeted.
Yesterday, Cathay flights CX828 and CX826 from Hong Kong arrived in Toronto five and four hours late respectively. Cathay said it aided passengers who missed connections.
An airline spokeswoman said operations to Toronto and London remained normal.
But she added: "We will closely monitor the weather conditions and will keep our passengers updated regarding the latest flight status."
Agence France-Presse, Associated Press, Bloomberg