Feb. 2 (Bloomberg) -- London and southeastern England were hit by the heaviest snowfalls in 18 years, with as much as 20 centimeters (8 inches) blanketing parts of the area, halting rail and bus services and disrupting airline and road traffic.

The meteorological service issued severe weather warnings for England, Wales, and parts of eastern Scotland, and predicted more snow tomorrow. Chris Almond, a forecaster at the Met Office, said the snows were the heaviest since February 1991.

About 6.4 million people, or 20 percent of the workforce, aren’t at work and the economy could lose as much as 1.2 billion pounds ($1.69 billion) in lost sales, the Federation of Small Businesses said. A one-day closure of the Tube, London’s metro system, can cost the capital as much as 48 million pounds in lost productivity, according to the London Chamber of Commerce.

Mayor of London Boris Johnson suspended the eight pound congestion charge for motorists driving into the capital today, and described the weather as some of the most challenging conditions London has faced in two decades.

“It is vital that we all pull together and pool resources to get London through this difficult situation,” Johnson said. “I urge everyone to consider how they will be traveling home and check the latest updates from Transport for London.”

The mayor said he has been liaising since dawn with the Transportation Commissioner, London Fire Brigade and the police. Some businesses were advising staff to leave the office early, allowing plenty of time to return home safely.

Shops Closed

Some shops in central London were closed this morning because employees weren’t able to make it into work, and Royal Mail said that collections and deliveries were being disrupted.

“Anybody trying to get in to London from southeast England or even from outer London is going to have considerable difficulty,” Nigel Bourne, director of the Confederation of British Industry, London, said in a telephone interview. “So many people are capable of working from home these days that it doesn’t mean the economy will grind to a halt.”

A limited bus service resumed in London on a small number of bus routes including 16, 36, and 73 in the center of the city, Transport for London said. London buses were suspended last night due to “treacherous road conditions” that led to traffic incidents. The agency said it aims to restore all services once roads have been treated and are safe.

Underground rail services were suspended or partially halted except for the Central, Northern and Victoria lines, according to a TfL spokesman.

As much as 15cm of snow fell in London’s Canary Wharf, 20cm in Balham, south London, 15cm in Northumberland, and 3cm in Cambridge, according to the Met Office.

Gas Prices

U.K. natural-gas for delivery today fell, reversing earlier gains, as shippers boosted supplies, which may exceed demand through 6 a.m. London time tomorrow. The within-day gas contract fell 0.55 pence, or 0.8 percent, to 65 pence a therm, according to broker ICAP Plc at 12:35 p.m. London time. That’s equal to $9.15 a million British thermal units. It earlier today rose as much as 8.3 percent. A therm is 100,000 Btus.

Demand through tomorrow at 6 a.m. will be 420 million cubic meters, the highest since Jan. 10, National Grid Plc, the pipeline-network manager, said today on its Web site. Demand was about 376 million on Jan. 30. Flows into the network were at the rate of 441 million cubic meters a day.

‘Extremely Icy’

Tomorrow will bring further snow into the western parts of England and Wales, Scotland and Northern Ireland, with some areas seeing a further five or six inches, according to the Met Office.

“This further snowfall, on top of what has already fallen, will cause further disruption, Helen Chivers, a Met Office spokeswoman said. ‘‘It will be extremely icy by Tuesday morning. With these conditions our advice to people is that if their journey isn’t essential then don’t venture out.”

“The system grinds to a halt with this much snow,” said Alden Skidd, 28, a management consultant from Toronto, Canada, who said he’s stuck at Heathrow Airport, unable to get a train back to central London and unable to board a flight to his next destination. “It would be business as usual in Canada, we have a better grip on how to deal with this sort of thing,” he said in a telephone interview.

BAA Ltd., the U.K. airport operator, said all its airports in the South East are experiencing delays and cancellations. It advised passengers to contact their airlines before leaving for the airport. Road and rail travel was also disrupted in the south east. British Airways Plc said it canceled all flights from Heathrow until 5 p.m.

Snow is forecast to continue throughout today, driven by icy winds from northeast Europe. The meteorological service said conditions will ease slightly on Feb. 4 before fresh falls at the end of the week.

Flights Canceled

Snow showers are expected across much of Europe, including Paris, Frankfurt and Vienna, according to a weather forecast by Meteorlogix LLC. Transport delays are possible in some parts of France and Germany, according to the meteorologists. Air France canceled 30 flights from Paris’s Charles de Gaulle airport.

The snow front, which is expected to last until at least tomorrow, will turn into rain by the time it reaches southern France and Central Italy.

Eurostar services, operating through the Channel Tunnel between the U.K. and the Continent, are subject to possible delays due to the heavy snow in the U.K. and northern France, according to an e-mailed advisory. Travelers who choose not to travel will be able to exchange their tickets, it said.

Both runways at Heathrow Airport shut down early today and 250 flights were canceled. London’s City Airport in the city’s eastern Docklands was closed. Gatwick and Stansted airports experienced significant delays and some cancellations, the airports’ operator said.

Plane Off Runway

BAA said last night it closed the single runway at Gatwick airport for two hours. Work crews de-iced the runway to open the airport today and more than 20 flights were canceled. Luton airport said flights faced disruptions. A Cyprus Airways plane slipped off the runway after landing at Heathrow, the British Broadcasting Corp. said.

The M25, London’s main orbital road, is gridlocked. The M20 highway from the southeastern port of Dover to London opened after being forced to shut, Highways Agency spokesman Anthony Aston said.

The agency said on its Web site that its national winter fleet, which consists of 500 salt spreaders and snow blowers, has already been used extensively this weekend with regular salt spreading taking place to help keep the traffic moving.

The Automobile Association warned motorists to ensure they keep warm clothes in their vehicles if they were planning to go out, or else risk “flirting with hypothermia.”

Trains Disrupted

England’s Southeastern train line that runs train services in Kent, south London and parts of East Sussex, is suspended until further notice. Services on the Heathrow Express train are suspended and a limited service is operating on Heathrow Connect trains between Heathrow and Paddington, according to an advisory.

“The rail service is knackered and there is no timetable,” Alex Bench, a spokesman for the British Transport Police.

Thousands of children across England woke up to the news their school was closed for the day, according to the BBC. In Essex, more than 370 are shut, while some 50 Kent schools have closed and in Suffolk about 125 gave their pupils the day off, the BBC said. Lincolnshire reported nearly 20 schools were closed. Some schools in Hertfordshire are shut.

To contact the reporters on this story: Caroline Alexander in London at calexander1@bloomberg.net; Brian Lysaght in London at blysaght@bloomberg.net.

Last Updated: February 2, 2009 09:48 EST