A massive winter storm system that whipped up tornadoes, ice and snow from the Gulf of Mexico to the Great Lakes and killed at least three people on Christmas Day was moving slowly eastward yesterday.

Hundreds of flights were cancelled and people were warned to stay home rather than brave the strong winds, freezing temperatures and treacherous roads. The National Weather service warned of “dangerous travel conditions due to snow and ice covered roads” and said the weight of ice and snow could knock down power lines and trees.

It forecast up to 46 centimetres from New York state up to Maine and warned of freezing rain and tornadoes all the way down to the Carolinas. Areas in the Rocky Mountains could also expect about 30 centimetres of snow. Nearly 700 US flights had been cancelled by yesterday morning after more than 500 were cancelled on Tuesday, according to FlightAware. “We expect the number of cancellations and delays to rise today and tonight,” FlightAware chief Daniel Baker said. Scores of homes and businesses were damaged on Tuesday after 34 tornadoes were reported in Texas, Louisiana, Alabama and Mississippi.

A 25-year-old man was killed in a Houston suburb after a tree fell on his pickup truck on Tuesday, the Houston Chronicle reported. A dozen people were hurt in a 21-vehicle pileup in Oklahoma City, the Oklahoman reported. Amanda Sue Goodman, 28, was killed in a separate crash in rural Oklahoma after the driver of the vehicle she was riding in lost control and hit a big rig on the snow-covered highway. The driver and a four-year-old girl were also hurt. Allen Sullivan, 53, was killed when a tree hit his home in rural Louisiana on Christmas Day, the News Star reported.