LONDON — A major storm with hurricane-force gusts is lashing southern Britain, causing flooding and travel delays including the cancellation of roughly 130 flights at London's Heathrow Airport.

Express train services between central London and Gatwick and Stansted airports were suspended because of the storm, and the major English port of Dover was closed, leading to a cutoff in ferry service to France.

Some regional rail lines shut down Monday morning, and some roads were closed due to fallen trees and power lines. There were severe delays on many parts of the London Underground network and the opening of the Overground network was delayed several hours.

Air travelers and commuters were advised to check conditions before starting any journeys. Widespread delays were expected as major London train lines delayed their opening because of the winds and tree hazards.

British Airways said its long haul flights were expected to operate normally but domestic and European flights were operating on a reduced schedule with some cancellations expected throughout the day. It said Gatwick and City airport operations should not be affected.

Weather forecasters say it is one of the worst storms to hit Britain in years.

Officials said many thousands of homes in southern England are without power. A spokesman said the majority lost power at about midnight but that crews were working to restore the service.

Flood alerts have been issued in many parts of southern England and officials said hundreds of trees had been knocked down by wind gusts.

Gusts of 99 miles per hour (160 kph) were reported on the Isle of Wight in southern England. Gusts in the 75 to 80 miles per hour range were reported on the mainland.

The storm has hurricane-force gusts but is not classified as a hurricane. It was not formed over warm expanses of open ocean like the hurricanes that often develop in the Caribbean and threaten the east coast of the United States.

A teenage boy is feared to have died after being swept to sea while playing in the surf off the coast of East Sussex.

Forecasters said the heavy winds should subside by mid-morning as the storm moves out to sea.