Significant Weather Blog: Sunday, November 30, 2025 6 PM

Potential Winter Storm for Portions of Interior Southern New England Tuesday Afternoon and Night

First measurable snowfall looks likely for much of interior southern New England Tuesday afternoon and night.  Since there remains uncertainty in the exact storm track and low level thermal profiles, at least some changes in the forecast are likely in the next 24 to 36 hours.

Discussion

Surface low pressure is expected to move from the mid-Atlantic coast to just a little southeast of New England Tuesday evening or early Wednesday morning.  This looks to be a rather progressive system (no blocking high pressure downstream) but fairly moist give source regions over the Gulf and southwest Atlantic.  Over the past couple of days, the various global computer models have converged on this track, although some variability remains with some operational and ensemble model runs taking the low center close to Nantucket and others having the low center pass a little offshore of the 40N70W “benchmark.”  This is a track rather favorable for snow across much of southern New England if cold air is locked in place.  There are a couple of significant complicating issues, however, with respect to the precipitation type forecast.  First, there is no reasonably strong blocking high pressure to the north over southeast Canada to hold cold air in place.  Second, sea surface temperatures remain relatively mild off the New England coast – in the upper 40s to around 50.

Given those sea surface temperatures and the lack of a high pressure center pouring an arctic air mass into the region, the precipitation will most likely be in the form of rain, perhaps mixed with wet snow at times, along the immediate coast.  Thermal profiles from nearly all computer models indicate that the precipitation should be mainly, if not all, snow across the higher terrain of north central MA, southwest NH, and the Berkshires.  The trickiest forecast is for the transition zone across the interior lower elevations between the coastal plain and the Worcester Hills as well as over the low hills of northwest RI and northern CT.  The best guess is the precipitation in this transition zone (interior lower elevations northwest of the I-95 corridor) will be in the form of wet snow mixed to a greater or lesser degree with rain.

Precipitation intensity and surface wind direction may help determine if the precipitation is more snow or rain.  More intense precipitation tends to drag colder air toward the surface, and more north versus east surface winds tend to hold back the milder maritime air at lower levels from intruding so far inland.

The more offshore scenario presented by the ECMWF and UKMET suite of models would result in less total precipitation over the northern Worcester Hills and Berkshires but would tend to focus the heavier snow axis over south central and east central MA as well as northern RI.  At this time, believe this may not be the most likely scenario but is still possible and bears watching.

At this time, there’s reasonably moderate to high confidence of plowable snow over the higher elevations of central and western MA and more rain than snow along the coastal plain.  It’s more of a tossup across the interior lower elevations as to how much the snow may accumulate as this area will be more sensitive to the exact track of the low and mid level low pressure circulation.

The Tuesday and Wednesday morning astronomical high tides are relatively high, but the most significant onshore wind is expected around the time of the lower Tuesday evening high tide.  Hence, any coastal impacts are likely to be rather minor with perhaps just some spotty splash over and beach erosion.  The erosion could be somewhat more significant along the Bay side of the Cape (e.g. Dennis, Eastham, Wellfleet, Truro) Wednesday morning given the combination of strong N to NW winds on the backside of the storm and a relatively high astronomical high tide.

Forecast

Snow or mixed rain and snow will spread across southern New England from southwest to northeast mid-morning to midday on Tuesday.  The precipitation will likely be heavy at time Tuesday mid-afternoon through Tuesday evening.  The precipitation should be mostly in the form of rain along the MA and RI coastal plain (east and southeast of the I-95 corridor), although wet snow may mix in at times from Boston northward (where a coating to an inch is possible back from the immediate shoreline).  Northwest of the I-95 corridor, wet snow or mixed rain and snow is likely – possibly accumulating 1 to 3 inches over Boston’s Metro West and northern RI.  West of I-495 in MA and north of I-84 in CT, there is a potential for 3 to 5 inches of snow at lower elevations and 5 to even 10 inches at higher elevations (above 700 or 800 feet).  The precipitation should taper off early Wednesday morning and likely be done by daybreak on Wednesday.  A shift south in the storm track could cause the axis of heaviest snow to shift further south and east.

Will continue to monitor this developing weather situation and likely provide an update sometime on Monday as additional information becomes available and trends become clearer.

About this Blog and Disclaimer

The National Weather Service monitors the weather 24/7 and updates forecasts, watches, and warnings as necessary.  For most of southern New England, refer to your local Weather Forecast Office for the latest forecast/warning information at weather.gov/box.  For information from other Weather Forecast Offices, go to weather.gov and click on the location of interest on the map.

A blog is issued when there is a potential risk of hazardous weather to southern New England and serves to provide background information regarding the significant weather with somewhat of an educational slant.  In the case of hurricanes, the author will attempt to issue a message when any portion of the United States coastline may be seriously impacted.  It’s intended to complement and not serve as an alternative to official forecasts issued by the National Weather Service.  Readers are urged to check National Weather Service forecasts and warnings for the most timely and updated weather information.  This weather message is solely produced by the listed author and does not constitute an official product of the Blue Hill Observatory and Science Center (BHOSC).

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 Message issued November 30, 2025 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Board member