LONDON — London’s Heathrow Airport says dozens of flights have been cancelled amid forecasts of snow and strong winds in Britain.

Heathrow, Europe’s busiest airport, said 80 out of about 1,350 flights scheduled Thursday have been cancelled pre-emptively because of the wintry weather.

Britain’s weather forecasters have issued warnings for snow for much of the country up until Saturday, with frequent snow showers and gales expected across Scotland, Northern Ireland and northern England. Sleet or snow may affect southern England as well.

Flight delays and cancellations are piling up in Oregon

A major snowstorm spread Wednesday through Portland and parts of Washington state, toppling trees, closing schools and cutting power to thousands in the city’s heaviest snowfall since 2008.

At Portland International Airport, flight delays and cancellations are piling up as the snow continues to swirl. Amtrak has suspended its southbound service between Seattle and Portland. No alternate transportation will be provided for the morning Amtrak Cascades service.

Meanwhile, those relying on Portland’s light-rail system continue to face delays because of ice, downed trees and fallen power lines. Shuttle buses are serving some stations.

The Oregon Department of Transportation urges drivers to stay off the road, and motorists appeared to be heeding that message. Many roads were empty Wednesday morning.

Extreme cold, high wind chill and dangerous travel in store for Prairies

Environment Canada has issued extreme cold mornings for most of the Prairies, saying that wind chill values could reach up to -45C into Thursday morning.

In Saskatchewan, RCMP were not advising travel anywhere in the province.

Similar warnings were issued in parts of Alberta including the Edmonton area, where the winds were gusting to 60 kilometres an hour at times, though Calgary appeared likely to escape the storm.

Europe: heavy snow brings more misery and travel delays

Authorities dug out stranded residents as heavy snow blanketed Eastern Europe Wednesday. As such, people struggled with travel delays, power outages and sub-zero temperatures. Homeless people and migrants were among those most at risk.

The recent cold snap has now been blamed for at least 66 deaths, and seen the lowest temperatures for decades in some parts.

Poland, the country hit hardest by the deep freeze, reported two more deaths Wednesday as havoc spread to many countries across the region.

Greece’s navy sent a ship to the island of Lesbos to house some 500 refugees and migrants. A medical association on the island said conditions at the main camp there were “inhuman” with migrants in tents exposed to freezing temperatures.

Swathes of northern and eastern Bulgaria were paralyzed by snowdrifts that blocked roads and left 117 towns and villages without electricity. The main highway linking the capital Sofia with the Black Sea port of Burgas was closed.

As temperatures plummeted to -25 Celsius, there were power outages in many areas. Meteorologists said it was the coldest weather since 1963, when the eastern city of Gjilan recorded a low of -32.5 Celsius.

In Romania, blizzards closed more than 130 roads and caused huge delays and cancellations on the railways.