London Heathrow cancels flights as snow sweeps across UK

London's Heathrow airport, the busiest in Europe, cancelled 225 flights and said others would be delayed as heavy snowfalls swept over southern Britain.

Services are alternating between the hub's two runways to allow for plowing, and people due to fly today should check with their airline before setting out, Heathrow Ltd. said. London City airport closed brief and Paris Charles de Gaulle will scrap one-fifth of flights from this evening as the snows spread east.

The U.K. Met Office issued a "red" alert for Wales, warning that some areas might have as much as 30 centimetres of snow. British Airways, Heathrow's biggest operator, scrapped mainly short-haul flights to cities including Paris, Barcelona and Berlin, though a trip to New York was also called off. Virgin Atlantic Airways Ltd. said it was suffering delays.

"We are keeping our schedule under constant review and will adjust it further if we need to," British Airways said. "If customers no longer wish to travel between Friday and Sunday they can rebook their flight to a later date."

UK rail services have also been affected, with Stagecoach Group Plc's South West Trains and Abellio's Greater Anglia among companies paring timetables in an effort to minimize disruption.

Eurostar Group Ltd., whose trains to London from Paris and Brussels have been brought to a halt during previous snowfalls, preemptively cancelled four services and lowered speed limits.

British Airways, a unit of International Consolidated Airlines Group SA, said on its website that a noon flight to Los Angeles would depart as scheduled, together with others to locations including Rio de Janeiro and Toronto. Trips to Copenhagen and St. Petersburg were among those cancelled.

Virgin Atlantic, a long-haul specialist, hadn't been compelled to drop any services, spokeswoman Anna Catchpole said.

Earlier in the day, Cardiff and Southampton scrapped flights earlier as the blizzards swept in from the west.

Gatwick, the U.K. capital's second busiest airport, is operating normally, though 5 centimetres of snow fell on its single runway. Stansted, the No. 3, said it's not suffering any disruption, while Luton, the headquarters for low-cost carrier Easyjet Plc, reported only brief delays for snow clearance.

London City Airport, favored by business travellers, re-opened after being closed for about 90 minutes for the removal of snow this morning, spokeswoman Geraldine Nolan said.

Gatwick has spent 8 million pounds ($13 million) on snow measures since 2010, boosting the fleet of plows and brushes to 98 vehicles. It also has enough de-icer to last 10 days, and has trained 43 non-operational staff to help keep the runway clear.

"It's snowing and it's accumulating, but the runway and taxiways have been treated with de-icer and we are currently operating as normal," the airport, located south of London and owned by Global Infrastructure Partners LP, said in a statement.

Thousands of homes in Wales were without power after supplies were cut by the snow, and as many as 400 schools have closed on the Isle of Wight and in Hampshire, southern England, according to the British Broadcasting Corp.

Temperatures in the UK are likely to remain around zero in London, the Met Office said, with the national forecaster warning of widespread icy roads.

Snowfalls yesterday led to hundreds of flight cancellations in Germany and Austria, curtailing service by carriers including Deutsche Lufthansa AG, Europe's second-biggest.

Munich airport scrapped 120 flights today, at least half as a knock-on from 345 cancellations yesterday, when runways were cleared a record eight times. Vienna lost 25 services this morning and anticipates that the situation will normalize as the day wears on, while Frankfurt airport, owned by Fraport AG, was operating as usual after about 40 cancellations yesterday.

In France, the civil aviation authority aims to ground 20 percent of flights at Charles de Gaulle and 10 percent at Paris Orly from 4 pm local time in anticipation of heavy snow this afternoon and overnight, it said in a statement.