From GYX:
On Sunday, all deterministic and ensemble models within the 12Z
model suite begin to shift the storm northeastward towards
southern New England. Models have trended towards a warmer
solution aloft, allowing for the snow to change to sleet and
possibly freezing rain over southern areas during the day.
Temperatures at the surface should remain below freezing over
southern areas which could potentially allow for a relatively
thick layer of ice.