Lexington Weather

Lexington, Massachusetts, USA

32°F

1/18/2026 9:29am

Lexington Conditions: Overcast
Temperature: 31.6°F / -0.2°C
Dew Point: 30.2°F
Relative Humidity: 94%
Wind: Calm, 10-min avg: Calm, gust: 3 mph
Barometer: 30.05 in Rising Slowly
Visibility: 7 miles
Snow Today: 0.0 in

Southeast Middlesex County, MA - Winter Weather Advisory
- SEE ALL NEARBY ALERTS -

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 180520
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1220 AM EST Sun Jan 18 2026

.WHAT HAS CHANGED...
A winter weather advisory has been issued for all of CT and into 
much of Eastern MA and RI. Confidence has increased for 2-5 
inches of snow across the advisory areas, with localized spots 
up to 6 inches possible in SE MA and RI. Confidence remains too 
low still for NW MA and for Block Island and Nantucket to be 
included in the advisory at this time.

&&

.KEY MESSAGES...

- Snow continues across NW MA this afternoon, ending after 5pm
  this evening. 

- Coastal low passes just SE of the Benchmark, bringing 2-5 
  inches with localized areas of 6 inches, especially in SE MA 
  and RI. 

- Arctic cold front pushes through Monday night bringing well
  below normal temperatures and bitterly cold conditions. The
  peak of this cold weather will be Tuesday into early Wednesday
  morning.

- Milder conditions arrive later Wednesday-Thursday, with
  perhaps a brief period of light snow showers or even light
  rain showers near the coast.

&&

.DISCUSSION...
KEY MESSAGE 1...Snow continues across NW MA this afternoon, 
ending after 5pm this evening. 

Snow begins to taper off across western MA this evening after
5pm as the mid level shortwave pulls away from the region and
drier air. Additional accumulations across western Mass could
reach 1-2 inches this afternoon. Snow transitions to rain as
precip approaches the coastal plain as temperatures are 
currently above freezing through midnight.


KEY MESSAGE 2...Coastal low passes just SE of the Benchmark, 
bringing 2-5 inches with localized areas of 6 inches, especially
in SE MA and RI. 

An elongated shortwave trough stretching from the northern Great 
Lakes down into the Gulf Coast will spin up a coastal low offshore, 
passing just southeast of the benchmark. Guidance continues to come 
into Better agreement on track with this low, but remains spread on 
how far NW the QPF field extends.  Guidance generally ticked up 
total QPF across the region with 1/2 to 3/4 inches across the Cape 
and Islands, and a 1/4 to 1/2 inch along and south of the I-95 
corridor.  How this translates into snowfall accumulation will 
depend heavily on temperatures and mid-level forcing.  Temperatures 
during this event will be marginal, with temperatures staying near 
freezing inland and at or above freezing for the Cape and Islands. 
This will impact snow totals as snow will melt and compress as it 
falls. Even areas inland will see very wet and heavy snow.  Even 
where temperatures are above freezing, still anticipating 
accumulations for temps between 32-35F as strong mid-level forcing 
will allow for precipitation to become heavy enough to drag down 
cooler air and remain as snow rather than turning to rain.  

The highest confidence in snow totals across the region is in SE MA 
and into RI, where strong mid-level forcing and temperatures near or 
below freezing will overlap.  Snow totals in this area will range 
from 3-5 inches, with localized areas reaching 6 inches. While there 
will be good forcing over Nantucket and Block Island, temperatures 
will likely be too warm for significant accumulations, but a slushy 
inch remains possible.  Across CT and into north-eastern MA, the mid-
level forcing is not quite as strong, but lower temperatures will 
allow for 2-4 inches, with localized spots up to 5 inches. 
Uncertainty is highest across NW MA, where a lack of mid-level 
forcing and dry air will limit totals. Still could see 1-3 inches, 
but if the low moves closer to the benchmark, these totals could 
increase, and the advisory could be expanded NW.

Timing this system out, A band of snow showers associated with the 
prefrontal wave moves into CT as early as 7 am, but most likely not 
arriving until after 10 am.  Snow spreads north and east into the 
rest of the region after the lunch hour.  Snow will initially start 
light with rates of under half an inch per hour.  Heaviest snow 
rates arrive later in the afternoon and into the early evening, with 
rates between 1/2 inch and 1 inch per hour through 10 pm to 
midnight.  Snow rates could exceed 1 to 1.5 inches per hour near the 
Cape and Far SE MA if temperatures are able to cool below freezing. 
Snow ends from west to east between 10 pm and 2 am, snow showers may 
linger into Monday morning.  Breezy winds are expected Monday 
afternoon behind the system, but given the wet and heavy nature of 
the snow, we do not anticipate blowing snow impacts on Monday. 


KEY MESSAGE 3...Arctic cold front pushes through Monday night 
bringing well below normal temperatures and bitterly cold 
conditions. The peak of this cold weather will be Tuesday into 
early Wednesday morning.

High pressure across the southern USA should combine with a low 
pressure over the Saint Lawrence Valley to funnel significantly 
colder air into our region towards the middle of next week. Strong 
signals in the ensemble data, with temperatures some 2-3 standard 
deviations below normal. While not quite at the minimum of 
climatology, still looking quite cold, especially at night. Gusty 
winds Tuesday should lead to minimum wind chill values in the single 
digits around 0F Tuesday morning.

KEY MESSAGE 4...Milder conditions arrive later Wednesday-
Thursday, with perhaps a brief period of light snow showers or 
even light rain showers near the coast.

Not anticipating quite as much wind into Wednesday as high pressure 
moves offshore of the Mid Atlantic coast, so some moderation in 
temperatures starts Wednesday. Winds turn more southerly ahead of a 
cold front, which is currently expected to move through some time 
Wednesday night into Thursday. Some light snow or rain showers could 
accompany this front. Colder air should return for late next week, 
with another period of below normal temperatures possible.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

TAF Update: 00z

Tonight: High confidence. 

VFR. Lull in activity. Light to calm wind. 

Sunday & Sunday Night: Moderate confidence. 

Between 12z-15z ceiling fall to MVFR/IFR from south to north as snow 
arrives. Periods of light snow overspreads the region with visby 
falling to 3SM-5SM. Steadier snowfall overspreads from south to 
north from 21z-00z, afterwards, snowfall rates could approach near 
1" per hour for terminals southeast of I-95. Snow ends west to east 
between 06z-09z, becoming VFR during this time frame as well. SW 
winds to begin on Sunday, briefly NNE 20z-02z, then to the NNW there 
after 02z.

KBOS Terminal...Moderate confidence in TAF.

VFR. Rain/Snow showers possible between 21z-23z, leading to a brief 
period of MVFR ceilings. VFR tonight, trending back to MVFR Sunday 
midmorning as snow arrives from south to north. Could arrive as 
early as 15z, but feel somewhat more confident with arrival around 
18z-20z. Conditions lower after 21z tomorrow with widespread 
snowfall. 

KBDL Terminal...Moderate confidence in TAF.

IFR/LIFR with moderate snowfall through 21z, improving conditions 
between 21z-23z. VFR tonight with light winds. Snow returning early 
Sunday morning.

Outlook /Monday through Thursday/...

Martin Luther King Jr Day through Monday Night: VFR. Windy with
local gusts up to 30 kt. 

Tuesday through Wednesday Night: VFR. Breezy. 

Thursday: VFR. Breezy. Slight chance RA, slight chance SN.

&&

.MARINE...
Today and tonight...High Confidence.

Residual seas of 5-8 feet on the southern waters and 3-6 feet on the 
eastern waters is the basis for a continued Small Craft Advisory on 
the outer waters, which is in effect through Sunday morning. Coastal 
storm passes off shore Sunday, bringing a rain/snow mixture and poor 
visby conditions. Brief lull in advisory level conditions, seas fall 
below 5 feet with light winds. Increasing wind speed/gusts with seas 
coming up late Sunday night into early Monday, likely will need to 
be handled with a renewed Small Craft Advisory. 

Outlook /Monday through Thursday/...

Martin Luther King Jr Day: Moderate risk for Small Craft
Advisory winds with gusts up to 30 kt. Local rough seas. 

Monday Night: Strong winds with gusts up to 35 kt. Areas of
rough seas. 

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

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

Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 25 kt. Seas up to 5 ft. 

Wednesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Areas of rough seas. Slight chance of
rain. 

Thursday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas. Chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Weather Advisory from 10 AM this morning to 10 PM EST 
     this evening for CTZ002>004.
MA...Winter Weather Advisory from 10 AM this morning to 4 AM EST 
     Monday for MAZ005>007-012>023.
RI...Winter Weather Advisory from 10 AM this morning to 4 AM EST 
     Monday for RIZ001>007.
MARINE...Small Craft Advisory until 10 AM EST this morning for ANZ235-
     237-250.
     Small Craft Advisory until 7 PM EST this evening for 
     ANZ254>256.

&&

$$

DISCUSSION...Belk/KP
AVIATION...FT
MARINE...Dooley