AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1201 PM EST Sun Feb 1 2026 .WHAT HAS CHANGED... Minor downward adjustments to snow accumulation expectations, otherwise no significant changes. Winter Weather, Wind, Coastal Flooding, Marine (Gale/Storm/Freezing Spray) and Cold Weather headlines remain valid. Snow may end up more showery than steady today, with manageable snow rates. && .KEY MESSAGES... - 730 AM Storm Update snow amounts reduced. Winter Weather Advisory cancelled except for Nantucket. We also issued a High Wind Warning for Nantucket. - Minor coastal flooding (1 to 2 ft inundation) with beach erosion along the eastern MA coast, with pockets of moderate coastal flooding for Nantucket. Due to cold roads and cold temperatures, storm surge could freeze and lead to prolonged impacts and delaying drainage. - Largely dry workweek with less-below-normal temperatures. A fast-moving Clipper low pressure brings potential for minor- accumulating snow Fri night into Sat, but following it is a likely shot of well below normal temperatures and gusty northwest winds late next weekend. && .DISCUSSION... Key Message 1: 730 AM Storm Update snow amounts reduced. Winter Weather Advisory cancelled except for Nantucket. We also issued a High Wind Warning for Nantucket. We made some updates to the forecast early this morning. Based on the latest radar/satellite imagery along with short term models...opted to drop the Winter Weather Advisory for all areas except Nantucket. Given the offshore track of the low pressure system...appears the steady snow shield will remain southeast perhaps only clipping the outer-Cape and Nantucket. We still expect some scattered ocean effect snow showers that may drop a coating to 2 inches of snow but probably not enough to justify continuing a Winter Weather Advisory. Greatest risk for 2 inches will be across Plymouth county into early afternoon and that will probably be in an narrow area. Across Nantucket...we opted to continue the Winter Weather Advisory. Although we are probably only looking at 1-2" of snow...felt its warranted given it will combined with very strong winds. Excellent transfer should result in northerly wind gusts of 55 to 60 mph and we upgraded to a High Wind Warning. Key Message 2: Minor coastal flooding (1 to 2 ft inundation) with beach erosion along the eastern MA coast, with pockets of moderate coastal flooding for Nantucket. Due to cold roads and cold temperatures, storm surge could freeze and lead to prolonged impacts and delaying drainage. There have been no significant changes regarding expectations for coastal flooding after reviewing latest tide/surge forecasts; Coastal Flood Advisories remain valid for the eastern coast of MA as well as Cape Cod and Martha`s Vineyard, with Coastal Flood Warnings for Nantucket. The coastal flood and beach erosion (waves around 20 ft) threat is expected to exist across three high tide cycle periods: around late this morning, tonight, and Monday morning. The rapid deepening rate of the surface cyclone down to sub-970 mb levels can itself cause elevated water levels (approx 1 ft of water rise per 30 mb decrease is a rough rule- of- thumb, due to less pressure/mass over the water). We still expect a 1.5 to 2.5 ft storm surge, with the highest surge near Nantucket where northerly winds will be the strongest. It still looks like this surge peaks around Sunday afternoon to early evening, when most tidal locations are in or slightly after low tide. Due the recent stretch of frigid temperatures and cold pavement, storm surge could freeze on shoreline roads and become slippery, while also leading to delayed water evacuation/drainage. Key Message 2: Largely dry workweek with less-below-normal temperatures. A fast-moving Clipper low pressure brings potential for minor- accumulating snow Fri night into Sat, but following it is a likely shot of well below normal temperatures and gusty northwest winds late next weekend. Dry northwest flow is maintained through much of the upcoming workweek, with the 500 mb pattern across CONUS being governed by a stubborn Rex block over the West Coast. Temperatures through late week modify to something closer to less-below-normal (relative to where we`ve been much of the week). Highs most days in the upper 20s to around freezing, though briefly dipping to around the upper 20s around midweek with a modest shot of colder air. A mid-level shortwave disturbance rounding the top of the West Coast ridge around Thu/early Fri helps energize a Clipper system moving through the Northeast Fri night into Sat. Accumulating snow is possible with the passage of this Clipper; being 6 days away plenty of time to evaluate this, but the progressive nature of the system probably caps how much falls. Perhaps the bigger story though is what lies behind the system: a period of strong NW winds with a shot of Arctic air (850 mb temps -18 to -21C, more typical of the type of cold we`ve had the last couple days) during the latter part of next weekend. Potential exists for additional cold and freezing spray headlines over the water for this, but there is time to evaluate this also. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18z TAF Update: This afternoon: Moderate Confidence VFR outside of southeastern MA terminals. NW winds gusting 20-25 knots across for interior terminals, 25-30 knots for coastal terminals, and 35-45 knots for the Cape and Island terminals. Tonight: Moderate Confidence Remaining MVFR CIGS become VFR by midnight. Snow should come to an end by 00z for the Cape and Islands with lingering gusty winds up to 30 knots. Inland terminals will see gusty winds end between 22-00z as the boundary layer decouples, however, this will create LLWS as winds aloft remains around 35-40 knots. Monday: High Confidence VFR with decreasing NW winds from 20 knots to under 10 knots. Monday night: High Confidence. VFR. Light winds becoming calm at some terminals. KBOS Terminal...Moderate Confidence in TAF. MVFR with intermittent VFR-visby ocean effect flurries/SHSN thru 15z. CIGS become VFR late this afternoon with gusty winds up to 30 knots. KBDL Terminal...High Confidence in TAF. VFR. Increasing northerly winds today, becoming gusty sunday afternoon up to 25 knots. Surface winds diminish after sunset Sunday, leading to LLWS concerns with winds aloft still around 35-40 knots. Outlook /Monday through Thursday/... Monday: VFR. Breezy. Monday Night through Thursday: VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. * DANGEROUS MARINE CONDITIONS EXPECTED TODAY A potent low pressure system will bring gale to storm force winds today and dangerous waves. Winds begin to increase this morning from the north gusting 30-40 knots in the near shore waters and 40-50 knots in the offshore waters including the ACK sound. Seas today quickly increase to 8-12 feet in the southern waters, and 12-15 feet in the eastern waters. On top of the dangerous winds and waves, freezing spray will also be a concern as cold air from over land gets advected out over the waters. Winds begin to diminish tonight and into Monday down to 15-20 knots from the west. Seas will lag behind the winds, still in the 5-10 foot range through Monday and dropping below 5 feet Tuesday morning. Outlook /Monday through Thursday/... Monday: Winds less than 25 kt. Rough seas up to 15 ft. Freezing spray. Monday Night: Winds less than 25 kt. Local rough seas. Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft. Tuesday Night through Wednesday Night: Winds less than 25 kt. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...Coastal Flood Advisory until 2 PM EST Monday for MAZ007-015- 016-019-022-023. Wind Advisory until 11 PM EST this evening for MAZ022-023. Winter Weather Advisory until 4 AM EST Monday for MAZ024. High Wind Warning until 7 PM EST this evening for MAZ024. Coastal Flood Warning until 2 PM EST Monday for MAZ024. RI...None. MARINE...Gale Warning until 1 AM EST Monday for ANZ230-233>235-237-256. Gale Warning until 4 AM EST Monday for ANZ231-250-251. Freezing Spray Advisory from 10 PM this evening to 10 AM EST Monday for ANZ231-232-255. Storm Warning until 1 AM EST Monday for ANZ232. Freezing Spray Advisory until 10 AM EST Monday for ANZ233-234. Freezing Spray Advisory until 7 AM EST Monday for ANZ235-237. Freezing Spray Advisory until 1 PM EST this afternoon for ANZ236-251-256. Gale Warning until 11 PM EST this evening for ANZ236. Storm Warning until 4 AM EST Monday for ANZ254-255. && $$