From the National Weather Service:
[945a update] Upped snowfall amounts w/ possible 1-2" in #Boston, higher N/NE; ice accretion not changed; impacts thru evening.
This morning ...
Will see a first batch of precipitation this morning concluding SW to NE towards noon into the early afternoon hours. Rain mostly for the S/SE coastal plain areas. A wintry mix over the CT River Valley into Worcester Hills with snow mostly further N/NE.
Already receiving reports of moderate to heavy snow along the east-half of the Mass-Pike extending east into the Boston-metro and on up north and northeast. A quick 1 to 2 inches is possible as are visibilities down to a quarter mile or less.
This afternoon ...
A second batch of precipitation is expected towards mid to late afternoon potentially concluding into the evening hours. Temperatures at the surface will moderate slightly warmer during the lull across the interior.
Expect a continued wintry mix of sleet and freezing rain over Western and Central MA as well as the higher terrain of CT, while more snow possibly mixing to sleet across N and interior NE MA. Locations around the Boston-metro should transition to rain with a more pronounced onshore flow. South and southeast locations (coastal plain) remain as rain.
Overnight we're anticipating precipitation to linger more across Northern and Western areas of MA and CT whereas areas south and east dry out. The event concluding towards Wednesday morning.
A wintry mix lingers across the high terrain of the Berkshires and perhaps the Worcester Hills adding to the overall ice accretion amounts.