Weather forecasters now warn of flooding as the snow melts in the north-east of the US.
Officials in New York state are worried some buildings may collapse when the rain arrives. The storms are blamed for at least 13 deaths in the area.
The state remains paralyzed by “historic” levels of snowfall.
The city of Buffalo was estimated to have received as much snow in three days as it normally gets in a year.
In parts of the city the snow was estimated to be as much as 8ft deep. Some areas received a further 3ft earlier this week.
The deaths of at least 13 people have been linked to the storms, mostly from exposure and heart attacks. Some of those who died were shoveling snow.
Weather forecasters have predicted light rain to begin over the weekend alongside warmer temperatures.
Officials in the Buffalo area of New York state have warned that the major concern now is the threat of roof collapses.
More than 30 collapses in the area have already been reported.
New York state Governor Andrew Cuomo said boats, pumps, sand bags and other equipment had been moved to western parts of the state to deal with potential emergencies.
He said: “If the temperature goes up as quickly as they are forecasting, there is a potential for building collapses, significant flooding.”
He added: “We don’t have a crystal ball. We can’t say exactly whether there will be a flooding problem. We can’t say what kind of structure collapses we’re going to have. But we anticipate both to some extent.
“Flooding can be terrible. I mean really terrible. Flooding can be worse than the snow.”
With many roads still impassable, sporting fixtures have either been postponed or cancelled.
A flood warning remains in effect in the counties of Erie, including the city of Buffalo, Genessee, Wyoming, Chatauqua and Cattaraugus, the National Weather Service said.
Lake-effect snow appears to be the cause of the blizzard that completely covered most parts of northwestern US states from November 18.
Lake-effect snow has been formed by cold air from the arctic sweeping over the Great Lakes – on the borders of the US and Canada – and picking up water vapor particles that are relatively warm in comparison. The same effect also occurs over bodies of salt water, when it is termed ocean-effect or bay-effect snow. The bands of freezing air then cool down the droplets until they are transformed into solid snowflakes, and this process can continue for as long as the two contrasting temperatures merge together. The areas affected by lake-effect snow are called snowbelts. The potential longevity of the snow can mean that New York, New Hampshire, Michigan, North Dakota, Minnesota, Massachusetts, Wisconsin, Ohio and Pennsylvania are likely to be covered in even more intense flurries before the rest of it gets a chance to be cleared or melt away. A very mild, warm and wet autumn coupled with arctic air hitting the Great Lakes is not unusual and only a small proportion of the US is affected by the lake-effect snow. A lake-effect blizzard is the blizzard-like conditions resulting from lake-effect snow. Under certain conditions, strong winds can accompany lake-effect snows creating blizzard-like conditions; however the duration of the event is often slightly less than that required for a blizzard warning in both the US and Canada.
The New York snowstorm has killed at least five people after dumping 5ft of snow in parts of the state.
The city of Buffalo was forecast to get 6ft later on November 19 with another storm due to wreak more chaos.
The storm was blamed for five deaths in New York state – one in a car crash, one trapped in a car and three from heart attacks.
Temperatures across all 50 US states plummeted to freezing, and there were several snow-related deaths elsewhere.
Residents were reported trapped in their homes and cars, and strong winds and icy roads caused motorway accidents and forced school closures in parts of the US.
A women’s basketball team from Niagara University was left stranded on a roadway for hours before being picked up by authorities.
New York Governor Andrew Cuomo deployed more than 100 National Guard members to assist in clearing roads and removing abandoned vehicles.
The National Weather Service said some places could top the record for a single-day of snowfall, which is 6ft 4ins.
Train service in parts of New York state was suspended on November 19, while long stretches of highway near Buffalo were shuttered.
As well as the fatalities in New York, there were two other weather-related deaths reported in New Hampshire and Michigan.
About 20 people have died across the US since November 15.
Three firefighters in Indiana were also injured when a trailer struck a fire truck on a snow-covered roadway.
Amid the weather, the State University of New York Buffalo announced it planned to go ahead with a nationally televised football game on Wednesday evening, although all pre-game activities were cancelled.
New York has been hit by the season’s first big snowfall.
On November 18, three feet of snow blanketed the Buffalo area and forced the closure of a 132-mile stretch of the state Thruway.
National Weather Service meteorologist Tony Ansuini said the storm was dumping 3 to 4 inches of snow per hour.
The Thruway Authority said white-out conditions caused by wind gusts of more than 30 mph forced the closure of Interstate 90 in both directions from the Rochester area to Ripley, on the Pennsylvania border 60 miles southwest of Buffalo.
In neighboring Orchard Park, the highway superintendent called the rate of snowfall “unbelievable,” while next door in Hamburg even police cars were getting stuck in the deep snow.
The National Weather Service warned that the snow off the Great Lakes would continue at least through November 19, affecting also Interstate 81 between Syracuse and the Canadian border.
Lancaster, just east of Buffalo, reported 42 inches by 9 AM, while just to the south, in Orchard Park, there was 36 inches. But typical of lake-effect snow, areas just a few miles away, including downtown and north Buffalo, had seen just a couple of inches.
State troopers were using all-terrain vehicles to deliver blankets and other emergency supplies to motorists stranded on the Thruway overnight, said state police Capt. Ed Kennedy. It wasn’t known yet how many people were stuck in their vehicles Tuesday.
The Tug Hill region on the eastern edge of Lake Ontario, notorious for its yearly snow totals, was bracing for 2 to 3 feet of snow.
The National Weather Service said the Lake Michigan shoreline could get 6 to 16 inches of snow by November 18, while 4 to 18 inches was forecast along Lake Superior.