The Union of Concerned Scientists told us, in this paper published in 2007:
Since 1970 the [U.S.] Northeast has been warming at a rate of nearly 0.5 degrees Fahrenheit (°F) per decade. Winter temperatures have risen even faster, at a rate of 1.3°F per decade from 1970 to 2000. This warming has been correlated with many other climate-related changes across the region, including… Less winter precipitation falling as snow and more as rain… All of these observed changes are consistent with those expected to be caused by global warming.
Brenda Ekwurzel, of the Union of Concerned Scientists, then told us, in this TV interview in 2011:
...our temperatures are increasing faster during the winter season than during the summer season. So that creates a situation when you have more moist conditions – it’s still below freezing – you can create very heavy snowfall. If you have very extreme cold, cold, cold conditions, you tend to have a little bit less precipitation in the form of snow. So ironically, we get a little more snow as we’re warming up the planet (H/T Alex Cull)