Flood warnings as snow set to melt in north-eastern US
Snowfall in the north-east of the US has subsided, forecasters say, but there are now warnings of flooding as the snow melts.
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 paralysed 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 2.4m (8ft) deep. Some areas received a further 0.9m (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 shovelling 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.
BBC weather forecaster Emma Boorman says that while such bad weather is not unheard of for this time of year, it is unusual.
Cold air has pushed south and moved over the relatively warm Great Lakes area - increasing the temperature contrast between the water and the air, which leads to vast and persistent snow showers.