Significant Weather Blog: Monday, December 1, 2025 4 PM
Winter Storm for Much of Interior Southern New England Tuesday and Tuesday Night
First measurable snowfall looks likely for much of interior southern New England Tuesday and Tuesday night. It still looks like mostly rain along coastal areas and heavy snow over the interior higher terrain. The majority of the overnight model runs were colder, but today’s runs turned warmer with a consensus storm track a little more to the northwest.
Discussion
Global and regional numerical weather prediction models are slowly converging on a storm track that has the low pressure center passing just inside the 40N latitude 70W longitude “benchmark” (about 85 miles or so south of Nantucket). As noted before, this is a favorable track for southern New England snowfall northwest of the I-95 corridor except for a couple of significant factors. 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.
This is expected to be a progressive system due to the lack of downstream blocking but quite moist (source regions including the Gulf and southwest Atlantic). The trickiest part of the forecast is determining the temperature profile in the lower layers of the atmosphere. There’s reasonable confidence that the air mass will remain cold enough for all snow over the higher elevations of southern New England (especially above 600 or 700 feet) as well as warm enough from low level onshore flow for rain along the coastal plain except possibly some light snow before ending late Tuesday night/early Wednesday morning (when the wind shifts to be from the north or north-northwest). The interior lower elevations remain more problematic as enough milder maritime air may erode some of antecedent low level cold air across eastern interior MA while a low level jet may also erode cold air at low to mid levels across southeast MA, much of RI and southern CT. It’s a close call as most model projections depict a near isothermal temperature profile near or slightly above the freezing mark for the lowest one to two thousand feet over interior eastern MA, the northwest RI hills, and northern CT (as well as up to the Mass Pike in south central MA). Current thinking is that there will be enough maritime air intrusion for mixed rain and wet snow for much of the day before turning to mostly snow by late afternoon or evening especially during periods of heavier precipitation. It is likely to be a wet snow, however, with low snow to liquid ratios in the interior, especially at the lower elevations.
In summary, expect enough cold air to support heavy snow over the interior high terrain with lower amounts over the interior lower elevations (although there could still be plowable snow even at low elevations west and northwest of I-495 in Massachusetts.
Any coastal impacts are likely to be rather minor with perhaps just some spotty splash over around the time of the Tuesday evening high tide. There is a risk, however, of minor to moderate beach erosion along the Bay side of the Cape (especially Eastham and Wellfleet area) 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 Timing:
Snow or mixed rain and snow will spread across southern New England from southwest to northeast during Tuesday morning. The precipitation will likely remain snow, heavy at times, across the interior high terrain Tuesday afternoon and evening. Across the interior lower elevations, the precipitation will likely be mixed rain and wet snow for much of the day before becoming mainly snow during the late afternoon or early evening. Rain is likely across the coastal plain (essentially along and southeast of the I-95 corridor) but may change to a period of snow before ending Tuesday night along the MA east coast including Boston. The precipitation should taper off during the early Wednesday morning hours and be offshore by daybreak Wednesday.
Projected snowfall:
No accumulation of snow is expected over the Cape and Islands. A coating to possibly up to an inch of snow is possible along the rest of the MA coastal plain (away from the immediate shoreline) north of the Cape Tuesday night when the precipitation may change to a period of wet snow before late Tuesday night/early Wednesday morning.
Boston’s metro west, northern RI, central CT: Possible 1 to 3 inches of wet snow, mainly falling Tuesday evening.
Interior east central MA, along the Mass Pike corridor west of I-495, high terrain of northwest RI, northern CT: Possible 3 to 5 inches with a risk of locally higher amounts. Most of the snow would probably fall during late Tuesday afternoon and/or Tuesday evening.
Higher terrain of central and western MA (essentially above 600 feet): Generally 6 to 10 inches of heavy, wet snow.
Impacts
There will likely be some impact to the morning commute across western MA and northwest CT. Travel will become increasingly difficult midday to early afternoon across the higher terrain of western and central MA. There could potentially be a high impact to the evening commute for most areas northwest of the I-95 corridor especially west and northwest of I-495, northwest RI, and northern CT. Conditions should be much improved by the time of the Wednesday morning commute.
Heavy wet snow loading on trees/wires could cause some power outages across the Worcester Hills and some Berkshire communities.
Since this is expected to be the first winter weather event for much of southern New England, the impact could be higher than one might expect with a similar storm later in the winter.
Will continue to monitor this developing weather situation and update as necessary.
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).
The frequency of this blog will depend upon the nature of the weather threat and availability of the author. Thus, for the latest information on weather forecasts and warnings, refer to the National Weather Service, which monitors and forecasts the weather 24/7.
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Message issued December 1, 2025 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Board member
