BOX AFD isn’t overly impressed which makes sense
Monday night into Tuesday... Model guidance in reasonable agreement on southern stream low tracking a bit south and east of the benchmark late Mon night into Tue. Much of the precip shield directly linked to this storm will be offshore. However, separate northern stream trough upstream will induce an inverted trough at the surface which extends into New Eng. This will be a focus for a period of precip Mon night within deepening moisture plume. There is uncertainty with the westward extent of precip and QPF amounts. GFS and much of its ensembles are furthest east and confine precip to eastern New Eng while Canadian ensembles are wettest and furthest west. We leaned toward ECMWF solution which is a compromise with ensembles supporting a light QPF event with somewhat heavier precip possible in the east. Regarding ptype, southerly flow preceding this event will warm boundary layer enough for mainly rain in the coastal plain including Boston to Providence, with best chance of snow further in the interior, especially north and west of I-495. Due to uncertainty with how far back the steadier precip gets this is looking like a minor snow event for the interior. We discounted the NAM solution which is a strong outlier. In fact, ensemble probs for greater than 3 inches from GEFS and ECMWF ensembles are near zero and only a few Canadian ensemble members have a more significant snowfall. Best chance for a few inches will be in the Worcester hills.