From BOX wrt this event:
Thursday night/Friday/Fri night... Potent upper low over the western Great Lakes ejects short wave energy toward SNE this period. Modest jet dynamics and moisture plume accompany this feature. However, given high latitude block, some duration to the precip, from Thu night into possibly early Sat morning. Ensembles (ECENS & GEFS) both supporting QPF ranging from 0.75 to 1.5 inches, with low probs of 2+ inches in spots. As for ptype, temp anomalies from the ensembles indicate airmass on the front end is only seasonably cold. Therefore, it will be difficult to maintain cold air, unless low level circulation from secondary frontal wave tracks offshore. There remains a large spread in the guidance regarding the track of this secondary wave, however, more members are farther west, tracking along the coast or across SNE. The GFS and its ensembles are on the east side of the envelope, hence a colder/snowier solution. Given the antecedent airmass is not anomalously cold combined with upper low over the western Great Lakes, the low level circulation likely won`t track offshore, and cold air should erode quickly. The exception will be across the high terrain of western MA, where cold air will linger longer, supporting the risk for several inches of snow. The ECENS has high probs for 3+ of snow here, GEFS is lower. Accumulating snow also possible for northern Worcester county, albeit lower probs than the Berkshires. Elsewhere, odds favor a chilly, windswept rain, especially for coastal plain, where a low level easterly jet of 40-50 kt quickly erodes the cold air. This strong low level jet may also translate to wind gusts up to 35-45 mph, so wind advisories may be need for the coastline.