Big Melt Will Start Liberating Boston From Its Record SnowpackBrian K. Sullivan
The Big Melt is coming.
In the next day or so, southern New England and the lower Hudson Valley are going to shed a lot of snowpack as a storm passing just north of the region pulls in warm air from the south and drops a soaking rain, said Ron Horwood, a meteorologist with the Northeast River Forecast Center in Taunton, Massachusetts.
“You are not going to lose all the snow, but there should be a fairly dramatic decrease in the overall extent in the next two days,” he said.
Boston received 110.3 inches (280 centimeters) of snow this season, an all-time high, according to the National Weather Service.
The city’s temperatures are forecast to reach 53 degrees Fahrenheit (12 Celsius) on Thursday and 48 on Friday, the agency said. New York may get to 55 and 48.
There is a chance that the rain combined with the melting snow will push some rivers close to flood stage, Horwood said. That will be especially true for the Merrimack River north of Boston and the Hoosic and Housatonic rivers in western Massachusetts. The Berkshires are forecast to “get a good slug of rain,” Horwood said.
The parts of the lower Hudson Valley that still have snow should also see a retreat in the cover.
The storm may free regional rivers from the ice that has hidden them from view for weeks, said Alison MacNeil, a hydrologist at the center.
The Charles River, which separates Boston from Cambridge, has been pinned under an ice sheet since January, although there are a few open spots, signs it’s trying to escape. It may finally get its chance.
“We’re expecting whatever ice is left could break up and move,” MacNeil said.
Water from the melting snow and rain will add to the flow of rivers, breaking up ice and moving it along downstream. It will take longer for ice to leave lakes and ponds, since they don’t flow, MacNeil said.
Forecasters tend to think about snow not in terms of how deep it may be. Rather, they look at how much water is locked up in the snowpack.
Across eastern Massachusetts right now there is from 3 to 6 inches of water in the snow, Horwood said. So, wringing out a third to half of that will make a dent in the crystallized, frozen clumps of gray that carpet lawns across the region.
The snow has long ceased being the fluffy powder it was when it fell from the sky. Now it looks as if it were jaded and disillusioned at the end of a hard life and no one wants it around anymore.
Because much of the snow is packed up in banks this week’s warm rain won’t sweep the region clean, Horwood said.
“It will increase the bare areas but you are not going to lose all the snow,” he said.
Of course, a person could seize this opportunity and attack those snow banks with a shovel, knocking them onto an open area, such as a driveway, to help nature along.