AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1211 AM EST Fri Dec 26 2025 .WHAT HAS CHANGED... Chances for accumulating snowfall increased Friday night into Saturday despite lower-than-normal forecast confidence. Winter Weather Advisory issued for tomorrow night into Saturday morning for Hartford and western Hampden counties. Gaining confidence in the risk for a period of freezing rain Sunday night into Monday. && .KEY MESSAGES... - Gusty winds move in briefly this evening following a cold front and temperatures fall into the teens and single digits. Wind chill values fall to 0F and below overnight. - Accumulating snow possible Friday night into Saturday morning. Uncertainty remains, but the highest chances for any plowable snow remain in western CT/MA. - Storm system around Sunday night into Monday could bring accumulating wintry mix (sleet/freezing rain) to rain. && .DISCUSSION... KEY MESSAGE 1...Gusty winds move in briefly this evening following a cold front and temperatures fall into the teens and single digits. Wind chill values fall to 0F and below overnight. A cold front passing through today will leave gusty NW winds in its wake this evening, along with temperatures below freezing that can be expected around 6 pm tonight. 925 mb temperatures overnight will dip to around -15C and lower as the colder air mass settles in post- front. Wind chill values will continue to fall as well, falling to around 0F and lower in some areas across southern New England. Winds this evening into early tonight may gust between 25-35 MPH for most, with the Cape and Islands having a brief chance at some gusts to 40- 45 MPH. Lows tonight will fall into the low teens and single digits across the region. Ahead of the next system, high pressure briefly moves over the region during the day Friday as winds drop off. Highs Friday will only climb into the 20s with a cold airmass aloft. KEY MESSAGE 2...Accumulating snow possible Friday night into Saturday morning. Uncertainty remains, but the highest chances for plowable snow remain in western CT/MA. The next disturbance comes in the form of a positively tilted shortwave and its surface low approaching the region Friday night. Snow would start to fall over the region after 7-8 PM tomorrow, continuing into Saturday morning. The latest high-resolution guidance has shifted the highest amounts and probabilities for more significant snowfall totals to the southwest once more. This is in line with the latest global guidance as well, which has trended the higher amounts towards NYC, SW CT, and across central NY. Probabilities for +2" of snow in Hartford and western Hampden counties are a little over 60 percent when looking at the NBM 5.0, though they drop off to around 20 percent or lower when considering totals at 4" or more. The NAM and Canadian deterministic models have totals around 3" in that area as well. Considering HREF guidance as well and the general track of this low pressure and shortwave aloft, keeping totals in Hartford and western Hampden counties between 3-4" seems to be the most reasonable approach at this time. Some uncertainty does remain, though, as the gradient between the higher and lower totals in this system is quite tight. So, any subtle changes in its track would alter expected snow totals. Stay tuned for future updates. In terms of snow totals outside of western MA and into CT, the rest of southern New England can expect between a coating and 2" of snow. Totals decrease as you move further east; central MA is more likely to get closer to 1-2" of snow, while eastern MA is more likely to be on the lower side. KEY MESSAGE 3...Storm system around Sunday night into Monday could bring accumulating wintry mix (sleet/freezing rain) to rain. We continue to monitor trends with a storm expected to impact southern New England some time Sunday night into Monday night. The track of this low pressure still appears to be well to our north and west, favoring a more wet-than-white forecast. Model soundings continue to forecast a significant warm nose on the order of +4-6C. The question then becomes what the surface temperatures will be below this warm layer. Such strong warm air advection is likely to lead to rising overnight temperatures Sunday night. It remains uncertain what the depth and extent of freezing air will be by the time the atmospheric column saturates enough to result in precipitation. At this time, favoring freezing rain over sleet, but there could be a brief period of that as well at the onset. The duration of freezing rain before fully transitioning to rain is also a source of uncertainty. Probabilities favor less than one tenth of flat ice accumulation. Still too early to pinpoint ice accumulations beyond that statement. The areas most at risk for freezing rain will be across western MA and along and north of Route 2 in MA. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Rest of Tonight...High Confidence VFR. Pockets of low-end SCT-BKN VFR ceilings across Cape Cod and the Islands. NW-NWW winds 15-20 knots, gusts 30 to 40 knots through the first half of the night, easing gusts fall between 20 to 30 knots during the predawn hours of Friday. Friday...High Confidence VFR. Gusty NNW winds to 25 knots early, easing late morning with a shift to the ENE. Winds speeds lowering to less than 10 knots. Friday Night...Moderate Confidence. VFR early, but falling to MVFR/IFR with areas of -SN. Areas with the greatest chance of impactful snow accumulation are western MA and central/western CT. Snow moves in from west to east between 00z and 08z. Light E/NE winds. KBOS Terminal...High confidence VFR. Winds NNW gusting 30 to 35 knots. Snow showers possible after 06z Saturday. KBDL Terminal...High confidence in TAF. VFR. decreasing north winds. Snow arrives after 00z tonight with a period of moderate to heavy snow possible between 02-05z. Outlook /Saturday through Tuesday/... Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance SN, chance FZRA. Saturday Night: VFR. Sunday: VFR. Slight chance FZRA. Sunday Night: Mainly VFR, with local IFR possible. RA, chance FZRA. Monday: Mainly MVFR, with areas IFR possible. Breezy. RA, FZRA. Monday Night: Mainly VFR, with local MVFR possible. Windy with gusts up to 35 kt. Chance RA, slight chance SN. Tuesday: VFR. Windy with gusts up to 35 kt. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Christmas Day through Friday NW-ly gusts 25-35 knots lasting until daybreak Friday. Seas 3-5 feet near the coast and 7-10 feet offshore. Winds on Friday become light NW-ly at 10-15 knots, with seas subsiding to 2-5 feet. Outlook /Saturday through Tuesday/... Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of freezing rain, slight chance of snow. Saturday Night through Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Sunday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Rain, chance of freezing rain. Monday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Rain. Monday Night: Strong winds with gusts up to 45 kt. Rough seas up to 16 ft. Rain likely. Tuesday: Moderate risk for gale force winds with gusts up to 40 kt. Rough seas up to 15 ft. Slight chance of snow. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory from 7 PM this evening to 10 AM EST Saturday for CTZ002. MA...Winter Weather Advisory from 7 PM this evening to 10 AM EST Saturday for MAZ009. RI...None. MARINE...Small Craft Advisory until 7 AM EST this morning for ANZ230- 233>237. Gale Warning until 7 AM EST this morning for ANZ231-232-250- 251-254>256. && $$