Small Craft Advisory 134, NWS Boston/Norton, MA

Area Forecast Discussion
National Weather Service Boston/Norton MA
1254 PM EST Wed Dec 24 2025

.WHAT HAS CHANGED...

Minor snow accumulations for portions of the south shore and
Cape Cod this afternoon.

Potential for accumulating snow for
Friday into part of Saturday mainly for western MA and northern
CT but still a low- confidence forecast. Another storm Sunday
night into Monday could bring an accumulating wintry mix to
rain.

&&

.KEY MESSAGES...

- Minor snow accumulations for portions of the south shore and
  Cape Cod this afternoon.

- Breezy with a few rain/snow showers Christmas Day.
  Temperatures fall quickly below freezing on Christmas Night
  with wind chill values in the single digits.

- Accumulating snow possible Fri night into early Sat for
  northern CT/western MA, with lighter snow accums (if any)
  north and east. Still a lower-confidence forecast.

- Storm system around Sunday night into Monday could bring
  accumulating wintry mix (sleet/freezing rain) to rain.

&&

.DISCUSSION...

KEY MESSAGE 1...Minor snow accumulations for portions of the south shore and
 Cape Cod this afternoon.

Ocean effect snow showers associated with an inverted trough
offshore can be seen on radar for much of eastern MA east of
I-95. Some minor accumulations up to an inch may be possible,
especially on The Cape where temperatures have dropped to near
freezing. Expect showers to taper off an hour or two after
sunset.

KEY MESSSAGE 2...- Breezy with a few rain/snow showers Christmas Day.
  Temperatures fall quickly below freezing on Christmas Night
 with wind chill values in the single digits.

Additional rain/snow showers possible across eastern MA early-
mid morning on Christmas Day. First half of the day is somewhat
pleasant by December standards with seasonable tempeatures and
light winds. During the afternoon however, a cold front will be
pushing in from the northwest resulting in a wind shift to the
northwest. This front will be accompanied by bitter cold
temperatures and gusty northwest winds between 25-35 mph
tomorrow afternoon into tomorrow night. Low temps in the single
digits on Friday morning with sub-zero wind chill temperatures.

KEY MESSAGE 3...Accumulating snow possible Fri
night into early Sat for northern CT/western MA with lighter
accums (if any) north and east. Still a low-confidence forecast.

We continue to monitor the Fri evening to Sat timeframe for possible
accumulating wintry weather, as a weak-amplitude mid-level shortwave
disturbance and sfc low pressure treks from the Gt Lakes
southeastward through the mid-Atlc region or as far north as
interior SNE. Seems to be a stronger consensus per AI-based
ensembles of accumulating snow potential mainly south and west of a
rough ORE-ORH-PVD line Fri night/overnight, tapering off early into
Sat. Besides continued storm track uncertainties which could shape
how far north and east accumulating snow could develop, we'll also
be coming out of a frigid/very dry airmass mainly for eastern MA/RI,
which on the flipside could blunt or even keep the northern end of
the precip shield from making it into SNE at all. Though the airmass
is plenty cold, most of the modest vertical motion that there is is
not collocated within the snow-growth region, so accumulation rates
also currently don't look substantial. Weighing the above, it
unfortunately remains a challenging, lower-confidence forecast and
the prospect of a very sharp SW to NE precip cutoff is in the cards,
way more sharp than available global models and AI-based ensembles
presently depict. It also wouldn't take much of a storm track
adjustment northward to put some of our far western/southwestern
counties into receiving more substantial amounts of snow (which
currently looked more primed for the lower Hudson Valley into the
PA/NJ/NY area), which in turn would also increase the potential for
accumulating snow further north and east.

Ensemble 24-hr snow probs show moderate (30-50%) probs of accums of
at least 3 or more inches in the Berkshires/western MA/Hartford and
Tolland Counties, with nil to low (0-20%) further north and east,
and there are nil probs for 24-hr snows in the 6 or more inch range.
Probabilistically-based Winter Storm Severity Index (WSSI-P) data
suggests high probs of a minor winter weather with low probs of a
moderate winter weather event for our northern CT and western MA
counties. At current, it looks like the best chance at adverse
travel impacts possibly needing winter weather headlines would be
for these locations; but as mentioned above, there are too many
uncertainties that need to be ironed out first before those are
considered.

KEY MESSAGE 4...Storm system around Sunday night into Monday
could bring accumulating wintry mix (sleet/freezing rain) to
rain.

In the wake of the Fri night/Sat system, the lower-level airmass
warms substantially and by Sun night brings 850 mb temps in the +4
to +6C range. Models show a more potent and moisture-laden low
pressure embedded in SWly flow aloft which looks to track to our
north and west Sun night, with some potential for secondary low
development based on some bagginess in sea-level isobars Mon. The
strength of the lower-level warmer air as mentioned above would
instead favor sleet/freezing rain at least at outset in most areas
Sun night, and then gradually transition to plain rain; timing of
whch varies depending on how quickly surface temps from Sunday night
can modify. We typically keep precip types simple (rain or snow) at
this extended range, but felt there was enough confidence in the
warm nose aloft to indicate wintry mix in the forecast. Too early
for specifics on accums at this range but the potential for an
accumulating ice event is possible in most areas, but especially so
for interior SNE N/W of I-95 which often struggles to scour out
colder air as quickly as blended models depict.

&&

.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

Through 00Z...Moderate Confidence

Mainly VFR with mid-level cloud decks between 3000-6000 feet.
Some patchy MVFR ceilings possible at times, especially along
the east coast of MA. Gusty northwest winds gradually diminish
below 20 knots by 00Z. Some light -RASN at BOS and over The
Cape/Islands terminals which may be accompanied by periods of
IFR/MVFR vsbys.

Tonight...High Confidence

VFR with lights winds. Some MVFR ceilings possible over The
Cape/Islands terminals.

Tomorrow...High Confidence

Generally VFR. Slight chacne for some rain/snow showers over BOS
and Cape/Islands tomorrow morning. Showers may be accompanied by
brief periods of MVFR vsbys/cigs. Best chance would be 12-18Z.
Southwest winds to start, but shifting to northwest after 18Z
with 25-30 knots gusts likely.

Tomorrow Night...High Confidence

VFR. Gusty northwest winds.

KBOS Terminal...Moderate confidence in TAF.

-SN/-RASN continues through 19-20Z with periods of MVFR
 civs/vsbys. VFR thereafer with gusty northwest winds
 diminsihing this evening. Slight chance for additional rain/snow
 showers tomorrow morning which may bring MVFR cigs/vsbys, but
 low confidence where rain/snow showers setup.

KBDL Terminal...High confidence in TAF.

Outlook /Friday through Monday/...

Friday: VFR. Windy with local gusts up to 30 kt.

Friday Night: Mainly VFR, with local IFR possible. Chance SN.

Saturday: Mainly VFR, with local MVFR possible. Chance SN.

Saturday Night: VFR.

Sunday: VFR. Chance FZRA, slight chance RA.

Sunday Night: Mainly VFR, with local IFR possible. Breezy. RA,
FZRA likely.

Monday: Mainly MVFR, with local IFR possible. Windy with local
gusts up to 30 kt. RA likely, FZRA likely.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Christmas Day

A gale warning remains in effect today as a cold front brings gusty
NNW winds of 30-40 knots.  Rough seas are anticipated today with 7-
10 foot waves offshore, and 4-6 foot waves near shore and in the
sounds.  Brief reprieve from the gusty winds tonight before stronger
winds arrive again for Christmas Day and night.  Gale force winds
from the NNW once again look possible starting in the late afternoon
to early evening.

Outlook /Friday through Monday/...

Friday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Areas of rough seas. Freezing spray, slight chance of
snow.

Friday Night: Winds less than 25 kt. Local rough seas. Chance
of snow. Local visibility 1 to 3 nm.

Saturday: Winds less than 25 kt. Seas up to 5 ft. Slight chance
of snow.

Saturday Night: Winds less than 25 kt. Seas up to 5 ft.

Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain.

Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Rain.

Monday: Strong winds with gusts up to 40 kt. Rough seas up to
14 ft. Rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Wind Advisory until 3 PM EST this afternoon for MAZ022>024.
RI...None.
MARINE...Gale Warning until 3 PM EST this afternoon for ANZ230>237-251.
     Gale Warning until 5 PM EST this afternoon for ANZ250-254>256.

&&

DISCUSSION...Loconto/RM
AVIATION...Loconto/RM
MARINE...Loconto/RM

Preliminary Local Storm Report
National Weather Service Boston/Norton MA
102 PM EST Wed Dec 24 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0615 AM     Snow             1 NW Sterling           42.44N 71.76W
12/24/2025  M2.5 Inch        Worcester          MA   Trained Spotter

0630 AM     Snow             2 SE Ashburnham         42.61N 71.89W
12/24/2025  M3.1 Inch        Worcester          MA   Trained Spotter

0700 AM     Snow             2 N Leyden              42.73N 72.61W
12/24/2025  M1.3 Inch        Franklin           MA   NWS Employee

0700 AM     Snow             1 SE Haverhill          42.77N 71.08W
12/24/2025  M1.2 Inch        Essex              MA   Amateur Radio

0705 AM     Snow             Hardwick                42.35N 72.20W
12/24/2025  M2.2 Inch        Worcester          MA   Amateur Radio

0715 AM     Snow             1 NE Baldwinville       42.61N 72.08W
12/24/2025  M3.0 Inch        Worcester          MA   Amateur Radio

0720 AM     Snow             Andover                 42.66N 71.14W
12/24/2025  M1.5 Inch        Essex              MA   Trained Spotter

0721 AM     Snow             1 SW Littleton          42.52N 71.49W
12/24/2025  M1.1 Inch        Middlesex          MA   Trained Spotter

0747 AM     Snow             1 W Pepperell           42.67N 71.61W
12/24/2025  M2.4 Inch        Middlesex          MA   Trained Spotter

0757 AM     Snow             2 SW Tewksbury          42.60N 71.26W
12/24/2025  M1.5 Inch        Middlesex          MA   Trained Spotter

0800 AM     Snow             2 SE Leominster         42.50N 71.74W
12/24/2025  M1.5 Inch        Worcester          MA   Trained Spotter

0809 AM     Snow             1 SE Fitchburg          42.58N 71.80W
12/24/2025  M1.8 Inch        Worcester          MA   Trained Spotter

0817 AM     Snow             New Salem               42.50N 72.33W
12/24/2025  M2.3 Inch        Franklin           MA   Trained Spotter

0828 AM     Snow             1 W Westminster         42.55N 71.91W
12/24/2025  M2.5 Inch        Worcester          MA   Trained Spotter

0835 AM     Snow             4 S Leicester           42.20N 71.91W
12/24/2025  M1.0 Inch        Worcester          MA   Amateur Radio

0930 AM     Snow             1 N Methuen             42.73N 71.18W
12/24/2025  M2.8 Inch        Essex              MA   Trained Spotter

0938 AM     Snow             1 N Methuen             42.73N 71.18W
12/24/2025  M2.8 Inch        Essex              MA   Trained Spotter

0940 AM     Snow             1 SW Gardner            42.58N 72.00W
12/24/2025  M2.8 Inch        Worcester          MA   Amateur Radio

1000 AM     Snow             Stow                    42.44N 71.51W
12/24/2025  M1.5 Inch        Middlesex          MA   Media

1007 AM     Snow             1 SW Haverhill          42.77N 71.11W
12/24/2025  M2.0 Inch        Essex              MA   Trained Spotter

1016 AM     Snow             1 S North Andover       42.69N 71.12W
12/24/2025  M1.0 Inch        Essex              MA   Trained Spotter

&&

Preliminary Local Storm Report
National Weather Service Boston/Norton MA
120 PM EST Wed Dec 24 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0115 PM     Snow             Newburyport             42.82N 70.89W
12/24/2025  M1.7 Inch        Essex              MA   Trained Spotter

&&

Preliminary Local Storm Report...Summary
National Weather Service Boston/Norton MA
128 PM EST Wed Dec 24 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0615 AM     Snow             1 NW Sterling           42.44N 71.76W
12/24/2025  M2.5 Inch        Worcester          MA   Trained Spotter

0630 AM     Snow             2 SE Ashburnham         42.61N 71.89W
12/24/2025  M3.1 Inch        Worcester          MA   Trained Spotter

0700 AM     Snow             1 SE Haverhill          42.77N 71.08W
12/24/2025  M1.2 Inch        Essex              MA   Amateur Radio

0700 AM     Snow             2 N Leyden              42.73N 72.61W
12/24/2025  M1.3 Inch        Franklin           MA   NWS Employee

0705 AM     Snow             Hardwick                42.35N 72.20W
12/24/2025  M2.2 Inch        Worcester          MA   Amateur Radio

0715 AM     Snow             1 NE Baldwinville       42.61N 72.08W
12/24/2025  M3.0 Inch        Worcester          MA   Amateur Radio

0720 AM     Snow             Andover                 42.66N 71.14W
12/24/2025  M1.5 Inch        Essex              MA   Trained Spotter

0721 AM     Snow             1 SW Littleton          42.52N 71.49W
12/24/2025  M1.1 Inch        Middlesex          MA   Trained Spotter

0747 AM     Snow             1 W Pepperell           42.67N 71.61W
12/24/2025  M2.4 Inch        Middlesex          MA   Trained Spotter

0757 AM     Snow             2 SW Tewksbury          42.60N 71.26W
12/24/2025  M1.5 Inch        Middlesex          MA   Trained Spotter

0800 AM     Snow             2 SE Leominster         42.50N 71.74W
12/24/2025  M1.5 Inch        Worcester          MA   Trained Spotter

0809 AM     Snow             1 SE Fitchburg          42.58N 71.80W
12/24/2025  M1.8 Inch        Worcester          MA   Trained Spotter

0817 AM     Snow             New Salem               42.50N 72.33W
12/24/2025  M2.3 Inch        Franklin           MA   Trained Spotter

0828 AM     Snow             1 W Westminster         42.55N 71.91W
12/24/2025  M2.5 Inch        Worcester          MA   Trained Spotter

0835 AM     Snow             4 S Leicester           42.20N 71.91W
12/24/2025  M1.0 Inch        Worcester          MA   Amateur Radio

0930 AM     Snow             1 N Methuen             42.73N 71.18W
12/24/2025  M2.8 Inch        Essex              MA   Trained Spotter

0938 AM     Snow             1 N Methuen             42.73N 71.18W
12/24/2025  M2.8 Inch        Essex              MA   Trained Spotter

0940 AM     Snow             1 SW Gardner            42.58N 72.00W
12/24/2025  M2.8 Inch        Worcester          MA   Amateur Radio

1000 AM     Snow             Stow                    42.44N 71.51W
12/24/2025  M1.5 Inch        Middlesex          MA   Broadcast Media

1007 AM     Snow             1 SW Haverhill          42.77N 71.11W
12/24/2025  M2.0 Inch        Essex              MA   Trained Spotter

1016 AM     Snow             1 S North Andover       42.69N 71.12W
12/24/2025  M1.0 Inch        Essex              MA   Trained Spotter

0115 PM     Snow             Newburyport             42.82N 70.89W
12/24/2025  M1.7 Inch        Essex              MA   Trained Spotter

&&