In Somerville, there's no parking allowed on major arteries during a snow emergency. You should be able to tell from their website (http://www.somervillema.gov/) whether the snow emergency is still in effect. You can tell whether a street is a "major artery" because it'll have a sign -- iirc, a squarish white sign with red lettering, mounted fairly high up on phone poles, saying "No Parking During Snow Emergencies."