textproduct: Boston / Norton

WHAT HAS CHANGED

No significant changes to the forecast for today.

KEY MESSAGES

- Strong to damaging wind gusts through tonight. Strongest winds expected over western and central Massachusetts.

- Extended period of below normal temperatures through Sunday. Nuisance snow showers at times, mainly New Years Eve night into New Year's Day. - Vessel icing due to accretion of light freezing spray over the waters is possible late this week into this weekend.

DISCUSSION

KEY MESSAGE 1...Strong to damaging wind gusts through tonight. Strongest winds expected over western and central Massachusetts.

Cold air advection began to dominate now that the front has passed through. Lapse rates look to be in the 7-8 C/km range as of midnight, and are projected to increase up to 10 C/km by sunrise. High resolution model guidance continued to indicate deep mixing in the 825-850 mb range, perhaps even a hair higher across the higher terrain areas. We're already seeing gusts 35-40 kts across the Berkshires and Worcester Hills this morning, and as this low pressure deepens and moves north through Atlantic Canada, the pressure gradient will only continue to tighten and further increase surface winds to 40-50 kts. Expecting winds to peak late this morning through early afternoon before slowly beginning to decrease through late tonight and early Wednesday morning.

Occasional light snow showers may reach the ground in western MA today as some of the lake effect snow coming off Lake Ontario moves across NY. Not expecting more than a trace to a coating of snow for any one given area.

KEY MESSAGE 2...Extended period of below normal temperatures through Sunday. Nuisance snow showers at times, mainly New Years Eve night into New Year's Day.

Expecting a persistent mid level trough to remain over the eastern half of the USA into this weekend. While there are timing and amplitude detail differences between various members of the latest guidance suite, this is broad agreement on the basic synoptic pattern. It's a pattern which favors reinforcing shots of cold, modified-Arctic air in the NW flow until the pattern breaks down, with weak-amplitude clipper systems being favored, not amounting to much in the snow department.

Anticipating below normal temperatures into the first week of 2026.

As for precipitation chances, this cold will be accompanied by generally dry weather. A reinforcing cold front New Years Eve night to early New Years Day could bring some decorative passing snow showers, but significant snow accumulation isn't likely for most. One possible exception for up to a couple of inches of snowfall could be toward the Cape and islands for a relatively rare ocean- enhanced snowfall from a southwest wind. Again, the progressive nature of this system should limit the time snow could accumulate.

KEY MESSAGE 3...Vessel icing due to accretion of light freezing spray over the waters is possible late this week into this weekend.

Mostly for marine interests, but with a prolonged period of cold air over the relatively milder ocean waters, periods of freezing spray could accrete on vessels through the first week of January. It doesn't look like anticipated freezing spray on any particular day would reach the moderate to heavy icing rates, which would necessitate freezing spray headlines for the waters. Days which have lower significant wave heights would have a lesser risk. However, we did want to give it at least a mention, since the risk for light vessel icing due to freezing spray could exist for a prolonged period given the spell of colder temperatures upcoming.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

Through Wednesday: High confidence.

VFR through the TAF period. Westerly winds gusting 30-40 kt this morning could gust at high as 50 kt later this morning into this afternoon. Wind gusts begin to slowly diminish closer to 35 kts late tonight into Wednesday morning.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Mainly VFR, with local MVFR possible. Breezy. Chance SN.

New Years Day: VFR. Breezy. Chance SN.

Thursday Night through Friday Night: VFR. Breezy.

Saturday: VFR.

MARINE

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

Gale-force westerly wind gusts up to 45 kt are expected today into tonight as strong cold air advection pushes through. Occasional gusts to 50 kt cannot be ruled out, but not of long enough duration to warrant an upgrade to Storm Warnings. Winds and seas begin to diminish late tonight into Wednesday morning. The risk for light freezing spray across the coastal waters, mainly the nearshore waters, begins this morning and continues into Wednesday.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of snow or rain. Local visibility 1 to 3 nm.

New Years Day: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Chance of snow. Local visibility 1 to 3 nm.

Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Chance of freezing spray, slight chance of snow.

Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of snow.

Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.

Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.

BOX WATCHES/WARNINGS/ADVISORIES

CT...Wind Advisory until 1 AM EST Wednesday for CTZ002>004. MA...Wind Advisory until 1 AM EST Wednesday for MAZ003-005>007- 010>024. High Wind Warning until 1 AM EST Wednesday for MAZ002-004-008- 009-026. RI...Wind Advisory until 1 AM EST Wednesday for RIZ001>008. MARINE...Gale Warning until 1 AM EST Wednesday for ANZ230-236. Gale Warning until 7 AM EST Wednesday for ANZ231>235-237-250- 251-254>256.