Stores across the Northeast were packed with shoppers as people prepared for what could be a historic blizzard set to arrive on Friday.

In Reading, Massachusetts, residents were preparing for several feet of snow that could leave them stuck in their homes for days.

"It's a zoo in there. There's nothing left on the shelves. ... I think I got every bottle of water that they had in stock," Elizabeth Fraiser told CNN afilliate WHDH.

At the Home Depot, another resident said she had essential supplies but wanted to be doubly sure she was ready.

"I have a lot of it, but just want to be prepared. You never know," Joanna Spinosa said.

A picture posted on the website of CNN affiliate WCVB showed long lines at a gas station in Boston.

Two ferocious storm systems are expected to converge across the Northeast on Friday and spawn travel nightmares for a large swath of the country.

A wintry blast churning across the nation and a cold front barreling up the East Coast will unite and could dump as much as a foot of snow in New York and up to 3 feet in Boston.

Nearly 3,000 flights were canceled in anticipation of the storm as emergency crews geared up for inclement weather, most of which was expected late Friday into Saturday.

Amtrak canceled many trips in the Northeast corridor. The rail transit company said on its website that northbound service from New York's Penn Station would be suspended after 1 p.m Friday.

Boston could see snowfall of 2 to 3 inches per hour, as frigid gusts swirl across the region. The system has already drawn comparisons to the "Great Blizzard" of 1978, when thousands were stranded as fast-moving snow drifts blanketed highways and left several people dead.

The most severe weather is expected to hit Massachusetts between 2 and 5 p.m. on Friday.

Gov. Deval Patrick announced Thursday that all non-emergency workers should work from home. He canceled all school classes on Friday.

"Be a good neighbor. Check on the elderly," he said, advising residents not to bring portable stoves, charcoal or gas grill indoors out of concern for potential fire hazards or carbon monoxide poisoning.

All vehicles must be off the roads by noon on Friday, and Boston's public rail system will halt service at 3:30 p.m. A fleet of 600 snow removers will be manned by municipal workers and contractors as authorities gear up for what they say could be a 36-hour storm.

"We are hearty New Englanders and used to these kinds of storms, but I also want to remind people to use common sense and stay off the streets," said Mayor Thomas M. Menino.

Forecasters warned of potential white-out conditions across New England and parts of New York.

"If you are on the highway and you are stuck, you are putting yourself in danger," said CNN meteorologist Chad Myers.

Meanwhile, residents stocked up after authorities announced that public schools across several New England states would not hold classes Friday.

"They're coming in buying shovels, ice melts and sleds," said Atton Shipman, who works at Back Bay Hardware in Boston.

Social media was abuzz with chatter about the incoming weather.

"Just a reminder of what the ground looks like in case anyone forgets in a couple of days," tweeted Ryan Pickering, after posting a close-up photo of a Rhode Island roadway.

Massachusetts Emergency Management Agency officials said that they were busy salting roadways.

"Travel may become nearly impossible with blowing/drifting snow and near zero visibility during the height of the storm (Friday afternoon into Saturday morning)," the agency said in a statement. "Motorized vehicles are asked to stay off the roads if they can during the storm to allow snow plows to clear the roads."

Crews began preparing snow plows at Logan International Airport, where officials said the storm is expected to cause more flight delays and cancellations.

United Airlines said customers in storm-affected cities will be allowed to reschedule their itineraries "with a one-time date or time change, and the airline will waive the change fees."

Delta, Jet Blue, Southwest and other airlines offered their customers similar assurances.

In Connecticut, Gov. Dannel Malloy said utility companies were bringing additional crews from out of state to deal with potential power outages. Metro-North rail lines could also be closed at any time should winds exceed 40 mph.

The Connecticut National Guard has moved equipment to staging places, including several Black Hawk helicopters at Bradley International Airport north of Hartford. In Rhode Island, 300 members of a military police brigade were scheduled to drill on Saturday and Sunday but the drill has been moved up because of the storm.

A snow emergency went into effect in the southern Connecticut city of Stamford, beginning at 5 p.m.