AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1242 PM EST Wed Dec 31 2025 .WHAT HAS CHANGED... Winter Weather Advisory expanded to include Cape Cod tonight into Thursday. Gale Warnings have been converted to Small Craft Advisories. && .KEY MESSAGES... - Dry and chilly today. Winds not as strong as yesterday. - Period of snow tonight into Thursday. - High pressure brings dry conditions and continued cold temperatures through the start of next week. - Light to moderate freezing spray over the waters is possible late this week into this weekend. && .DISCUSSION... KEY MESSAGE 1...Dry and chilly today. Winds not as strong as yesterday. Pressure gradient relaxes significantly compared to yesterday. Expecting more of a southwest wind today as well. Thus, the current lake effect snow bands should end later this morning across portions of western MA. Not expecting much in terms of snow accumulation for the rest of this morning. For most of southern New England, today will be dry and not quite as cold as yesterday. KEY MESSAGE 2...Period of snow tonight into Thursday. There is growing confidence in a period of snow starting this evening and ending Thursday morning, coinciding with New Year`s Eve celebrations. Please plan accordingly. Confidence remains high in a light snowfall across most of southern New England. This will be the result of a potent mid level shortwave arriving about the same time as an arctic cold front. Anticipating just enough lift to squeeze the limited moisture into some fluffy snow. Timing-wise, thinking snowfall starts to arrive from west to east between 9 PM and midnight for most, with the heaviest snowfall between 3 AM and 7 AM across portions of southeast MA. Latest high resolution guidance continued to give confidence in the risk for ocean-enhanced snowfall across portions of southeast MA. With water temperatures around 40F, that will lower snow:liquid ratios slightly. That said, still expecting a fluffier snow across southeast MA. The main limitation on snowfall will be its duration, as this arctic front is quite progressive and much drier air should follow behind it. 31/00Z HREF had a rather strong signal for around 1 inch/hour snowfall rates across portions of RI and southeast MA late tonight. The Winter Weather Advisory was expanded to include Cape Cod tonight for snowfall totals of 2-4 inches. There is still a chance this advisory may need to be expanded into Bristol and Plymouth Counties in MA. Do not have enough confidence in seeing more than 3 inches of snowfall there but it could be close, especially towards the South Coast. Snow ends mid to late morning on New Year`s Day, followed by dry and cold conditions. Breezy northwest winds with gusts 20 to 30 mph leads to feels-like temperatures in the single digits and teens at times. KEY MESSAGE 3...High pressure brings dry conditions and continued cold temperatures through the start of next week. By Friday, high pressure will begin to dominate across southern New England and a dry pattern will emerge. High pressure combined with 925 mb temperatures between -10C and -15C will allow for high temperatures through Monday to remain relatively stable, in the mid 20s to lower 30s. Overnight lows are likely to be slightly more variable, in the mid teens through the first half of this weekend, then dropping to single digits to lower teens by Sunday night. Some guidance is indicating southern New England could see another round of snow on Monday. However, uncertainty on timing, placement, and snow amounts remains high. Something to keep an eye on through this weekend. KEY MESSAGE 4...Light to moderate freezing spray over the waters is possible late this week into this weekend. A lengthy period of cold air over the warmer waters will give rise to the likelihood of freezing spray becoming a concern for mariners through a good portion of this weekend. As we get closer to this weekend, guidance has trended slightly higher with the risk for pockets of moderate freezing spray. Will need to monitor these details over the coming days, as freezing spray marine headlines may be needed across some of the southern inner waters. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18z TAF Update... This afternoon into Thursday morning...High confidence. VFR into this evening. A steady shield of snow should overspread the region from west to east in the 03z to 06z time frame. This will result in IFR to briefly LIFR conditions developing. Ptype should be all snow except for ACK where a period of rain or rain and snow mixed will occur. Steady shield of snow departs by 10z/11z...but lingers a few hours longer near the Cape and Islands. In addition...a cold front may trigger brief scattered snow showers and perhaps a localized snow squall or two between 10z and 15z. Total snow accumulations of 1 to 4 inches with the higher amounts near the south coast and western Hills of MA/CT/RI. SW winds 5-12 knots tonight shifting to the WNW with gusts of 25-35 knots developing Thursday morning behind the cold front. Thursday afternoon and night...High confidence. VFR conditions. WNW wind gusts of 25 to 35 knots Thu afternoon gradually diminish Thu night and become more westerly. KBOS Terminal...High confidence in TAF. Snow arrives after 05z/06z and continues until about 10z/11z. A brief round of scattered snow showers and perhaps a localized snow squall will then be possible with the cold frontal passage through about 15z. KBDL Terminal...High confidence. High confidence in TAF. Snow arrives after 04z/05z and continues until about 08z/09z. A brief round of scattered snow showers and perhaps a localized snow squall will then be possible with the cold frontal passage through about 13z/14z. Outlook /Friday through Sunday/... Friday through Saturday: VFR. Breezy. Saturday Night through Sunday: VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Tonight through Wednesday...High confidence. Winds and seas continue to diminish this morning. However, it will take some time for seas to subside less than 5 feet across the outer coastal waters. Expecting to convert the remaining Gale Warnings to Small Craft Advisories by daybreak. The risk for light freezing spray across the coastal waters continues, mainly across the eastern nearshore waters this morning. The risk for more widespread freezing spray should return Thursday. Outlook /Thursday Night through Sunday/... Thursday Night: Strong winds with gusts up to 35 kt. Areas of rough seas. Freezing spray. Friday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Freezing spray, slight chance of freezing rain, slight chance of snow. Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Sunday: Winds less than 25 kt. Slight chance of snow. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...Winter Weather Advisory from 7 PM this evening to 1 PM EST Thursday for MAZ022>024. RI...None. MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ232>234-237. Small Craft Advisory until 4 PM EST this afternoon for ANZ235- 250. Freezing Spray Advisory from 7 PM Thursday to 7 AM EST Friday for ANZ250-251. Small Craft Advisory until 7 PM EST Thursday for ANZ254>256. Freezing Spray Advisory from 4 AM Thursday to 7 PM EST Friday for ANZ256. && $$