Small Craft Advisory 15, NWS Boston/Norton, MA

Area Forecast Discussion
National Weather Service Boston/Norton MA
139 AM EST Tue Jan 27 2026

.WHAT HAS CHANGED...
No significant changes. Confidence remains high on well below normal
temperatures this week with another surge of Arctic air Thursday
night into Friday.

&&

.KEY MESSAGES...

- Mainly dry with well below normal temperatures this week, and
  potentially hazardous wind chills Thursday night into Friday.

- Monitoring a possible late-weekend East Coast US storm which
  could threaten Southern New England or remain too far
  offshore, but uncertainty remains large.

&&

.DISCUSSION...
Key Message 1...Mainly dry with well below normal temperatures this
week, and potentially hazardous wind chills Thursday night into
Friday.

High pressure builds into region with mainly dry but continued cold
temperatures this week. We may see some flurries or snow showers
Thursday ahead of a more significant arctic front which is followed
by yet another reinforcement of arctic air Thursday night into
Friday. During that time, we may need cold weather headlines for
wind chills well below zero. On the coastal waters, this should
bring another round of Gale force winds and at least light freezing
spray.

Key Message 2...Monitoring a possible late-weekend East Coast
US storm which could threaten Southern New England or remain too
far offshore, but uncertainty remains large.

We continue to monitor trends pertaining to a possible coastal
system which could threaten Southern New England late this
weekend/Sunday, one which has garnered quite a bit of buzz early
this week given the recent snowstorm. An amplified and rather
complex 500 mb configuration develops in Canada, with an upper
ridge over western Canada helping to consolidate and drive
southward a complex upper trough near Hudson Bay/central Canada
around mid to late this week, digging and potentially closing
off somewhere either into the Ohio Valley and/or Deep South
around late week or early this weekend. This closed upper
feature will also be associated with a strong reservoir of cold
air, with sfc low development near or just offshore the US East
Coast. Interaction of this cold air with the mild Gulfstream
waters could really help to deepen/enhance a coastal low through
air-sea baroclinic influences, with most ensemble members
depicting a sub- 990 mb low with varied placement either
somewhere along or offshore the US East Coast and then pass in
vicinity of 40N/70W.

Although this storm could have a higher ceiling given the above
and we'll continue to monitor, there are otherwise still too
many uncertainties at this Day-6 timeframe that need to be
ironed out. It thus remains way too early to lock into any
potential outcome at this time - ranging from a significant
slow-moving winter storm to a dry pass offshore. Noted several
individual spokes of vort energy rotating around the central
Canada trough before it starts to consolidate/dig southward into
the north- central US around mid to late this week, and any
subtle change in any of those vort maxima could have substantial
implication on what transpires. Ensemble cluster analysis even
reflects this, showing sensitivity to details pertaining to how
soon, how strong and how far south will this digging trough-to-
closed-low evolve. Those elements are things we'll be monitoring
in particular, but we may not have a great handle on how that
interaction shakes out until midweek at earliest. Given the
large spread, instead of buying off on one solution, it's more
prudent to continue to "dollar-cost-average" what the ensembles
and AI-trained guidance tell us over the next few days until
there's more convergence on a more- likelier outcome.

Astronomical tides also look higher than this past storm with
Boston at 11.0 ft, Providence at around 5.17 ft, and Nantucket
around 4 ft for the Sunday morning Feb 1st high tide, so
potential for coastal flooding will also have to be monitored.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...

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

06Z TAFs: High confidence.

Back edge of -SHSN was moving offshore followed by rapid
improvement to VFR with clearing taking place overnight.
Increasing NW winds gust to 25-35kt, strongest near Nantucket.
Winds back to W and SW Tue and gradually diminish, but gusts to
25kt should persist much of the day near Cape Cod and the
Islands. VFR ceilings Tue afternoon may become MVFR Tue night
near South Coast.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: VFR.

Thursday through Friday Night: VFR. Breezy.

Saturday: VFR. Slight chance SN.

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence this week.

Gale Warnings and Freezing Spray Advisories remain posted for most
of coastal waters throough today, although strongest winds will
persist through the morning. Much of the week will feature gusty
winds to SCA levels and rough seas along with bands of snow showers
mainly offshore.

Another round of Gale force winds and at least light to moderate
freezing spray appears likely Thursday night into Friday.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Winds less than 25 kt. Seas locally
approaching 5 ft. Slight chance of snow.

Thursday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of seas approaching 5 ft. Slight chance of
snow.

Thursday Night: Strong winds with gusts up to 30 kt. Local
rough seas. Chance of freezing spray.

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Local rough seas. Chance of freezing spray.

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

Saturday: Winds less than 25 kt. Slight chance of snow.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 AM EST this morning for ANZ230-
     236.
     Gale Warning until 10 AM EST this morning for ANZ231>235-237-
     250-254>256.
     Freezing Spray Advisory until 10 AM EST this morning for
     ANZ231-235>237-250-251-254>256.
     Freezing Spray Advisory until 1 PM EST this afternoon for
     ANZ232>234.
     Small Craft Advisory until 10 AM EST this morning for ANZ251.

&&

DISCUSSION...Loconto/JWD
AVIATION...Loconto/JWD
MARINE...Loconto/JWD