Significant Weather Blog: Thursday, December 11, 2025 6 PM
First Accumulating Snow of the Season Possible for Southeast New England on Sunday
A storm passing offshore on Sunday is expected to be rather fast moving with intensification taking place downstream from southern New England. Nevertheless, it looks as though the system may pass close enough with a fairly vigorous upper trough to provide enough moisture and lift for at least light accumulations of snow across southern and central Connecticut, much of Rhode Island, and southeast Massachusetts including Cape Cod and the Islands during Sunday. There is a possibility of some ocean effect enhancement along the South Shore and the Cape. Also, due to a deep cold air mass, there could be rather high snow to liquid ratios of 15 to 1 or even 20 to 1.
The various computer models (and their ensembles) are not in alignment with the track and rate of intensification for this system. Thus, much uncertainty remains. A very early rough estimate is that a coating to an inch of snow may fall along the Mass Pike (I-90) corridor and possible 1 to 3 inches of snow along and southeast of the I-95 corridor. It’s not out of the question that ocean effect enhancement (due to the low-level instability induced by cold air flowing over warmer water – somewhat analogous to lake effect snow processes) may result in locally heavier amounts in a few coastal areas of Plymouth County and the Cape. This very early estimate is subject to change (in either direction) as the various computer models grapple with the upper-level jet dynamics and whether multiple packets of energy have an opportunity to start phasing before moving beyond our area.
This system would ordinarily not induce a message blog except it has a chance of producing the first accumulating snowfall for this season across the southern New England coastal plain, even if amounts are anticipated to be light. Will continue to monitor this weather development and will likely provide an update sometime tomorrow (Friday).
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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 December 11, 2025 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Board member
