High pressure briefly will be in charge across New England but low pressure from northern Canada and associated low forming over the plains will merge, then pass west and north of New England on Tuesday. Snow develops in the afternoon and spreads from west to east, but as warmer air moves in, moderate to heavy snow will transition to a wintry mix of sleet and freezing rain... followed by all rain overnight into Wednesday morning.
On Tuesday evening we could see snowfall rates of one inch per hour before we make the transition to a wintry mix/rain. Expect the change-over time period to be during the late evening between 9 p.m. to 11 p.m. During that particular time, icy road conditions and slippery travel, especially across the interior southern New England will be a concern.
Once we change to all rain overnight, the threat shifts to poor draining flooding, especially because of clogged drains. In addition, roof collapses will once again be a possibility with the added weight of snow & liquid water.
The storm departs on Wednesday afternoon and we warm into the 40s. On Thursday morning, however, another chance of accumulating snow for southern New England is possible. Dry and cold weather returns for the end of the week.