Lexington Weather

Lexington, Massachusetts, USA

39°F

1/8/2026 11:23am

Lexington Conditions: Clear
Temperature: 39.2°F / 4.0°C
Dew Point: 38.1°F
Relative Humidity: 96%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 30.09 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 031714
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1214 PM EST Sat Jan 3 2026

.WHAT HAS CHANGED...
More guidance has begun to show a chance for mixed precipitation 
or freezing rain Tuesday night into Wednesday.

&&

.KEY MESSAGES...

- Dry start to weekend followed by light snow possible Sunday. 

- Chance for snow and a period of mixed precipitation Tuesday 
  night into Wednesday of next week.

&&

.DISCUSSION...
Key Message 1...Some light snow possible Sunday.

Weak high pressure to the south of New England will keep a front
stalled across southern NH/VT into Sunday. A modest mid level
shortwave is projected to pass by our region late tonight into
Sunday morning. This combination should result in some snowfall
across our region after midnight Sunday through about daybreak
for most. The main limitation here is the amount of moisture.
Ensembles have very low probabilities for more than a couple of
hundredths of an inch of liquid equivalent. Thus, not expecting
much accumulation, where it snows at all. Snow may linger a bit
longer across the Cape and Nantucket due to some ocean 
enhancement as winds shift northwest Sunday morning.

Precipitation chances may be raised with later forecasts if
confidence grows in a more widespread event. Even if that
occurs, that still would not mean much more in terms of 
snowfall. Thinking most locations across southern New England 
should at least see a period of snow late tonight. Am just not 
confident that precipitation will be measurable.

KEY MESSAGE 2...Chance for snow and a period of mixed
precipitation Tuesday night into Wednesday of next week.

High pressure builds in Sunday night into Monday ahead of the
next system expected to impact southern New England. A weaker
disturbance may move through Monday night into Tuesday as high
pressure exits, leading to the chance for some scattered snow
showers. However, the main concern starts Tuesday night as a
much more potent system moves into the region.

With the persistent trough from this past week shifting off to
the east, another wave makes its way towards New England from
the Great Lakes. Warmer air gets the chance to move in from the 
south behind a slow-moving boundary that becomes more of a warm 
front. 925 mb temperatures go from around -10C to 0C, with some 
guidance indicating a chance at temperatures up to 4C. As this 
warmer air moves in, model soundings continue to show a
significant warm nose despite colder surface temperatures.
Latest ensemble guidance still doesn't indicate much in terms of 
possible ice accumulation, but it remains supportive of at least
0.01" in the interior, particularly in the CT River Valley and
into northern MA. Lingering chances for precipitation during the 
day Wednesday would likely fall as just rain as surface
temperatures may improve into the 40s with warmer air continuing 
to sit aloft. However, it is worth noting that as this event is
still a few days away, exact details regarding ptype and timing 
are uncertain. Depending on how the colder air at the surface 
holds on Tuesday night, the higher chances for mixed
precipitation could shift in location. The Canadian guidance,
for example, continues to trend the higher chances for freezing 
rain across CT and RI while the GFS and ECMWF are more in
agreement with it being across northern MA and the CT Valley.

Ridging and surface high pressure build back in over the region 
heading into Thursday, bringing the return of drier conditions.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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


Tonight...High confidence.

Mainly VFR becoming MVFR late. Winds become light and variable.
A chance for -SN after midnight.

Sunday...High confidence.

Light snow ends from W to E around daybreak. -SN may linger
across the Cape and Nantucket as winds shift NW Sunday morning.
Mainly VFR during the day, with brief MVFR in snowfall.

KBOS Terminal...High confidence in TAF. 

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Wednesday/...

Sunday Night: VFR. Breezy. 

Monday: VFR. 

Monday Night: Mainly VFR, with areas MVFR possible. Slight
chance SN.

Tuesday: Mainly VFR, with local IFR possible. Slight chance RA.

Tuesday Night: Mainly VFR, with areas IFR possible. Chance RA,
chance FZRA.

Wednesday: Mainly VFR, with local IFR possible. Chance RA,
chance FZRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

High Confidence.

Gusty W winds diminish after sunset this evening, then shift NW
after midnight. Threat for light freezing spray on the eastern
waters this morning. Seas continue to subside this morning.
Expecting that all remaining Small Craft Advisories will be able
to end by this afternoon. Relatively light winds and seas for
Sunday. Reduced visibility in light snow late tonight into
Sunday morning.

Outlook /Sunday Night through Wednesday/...

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft. Freezing
spray, slight chance of snow. 

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

Monday Night: Winds less than 25 kt. Slight chance of rain,
slight chance of snow. 

Tuesday: Winds less than 25 kt. Slight chance of rain. 

Tuesday Night through Wednesday: Winds less than 25 kt. Chance
of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ250-
     254-255.

&&

$$

DISCUSSION...Belk/Hrencecin
AVIATION...Belk/FT
MARINE...Belk/Hrencecin