Lexington Weather

Lexington, Massachusetts, USA

37°F

1/11/2026 11:29am

Lexington Conditions: Mostly cloudy
Temperature: 37.2°F / 2.9°C
Dew Point: 36.1°F
Relative Humidity: 96%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.65 in Falling Slowly
Visibility: 10 miles
Rain Today: 0.07 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 091145
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
645 AM EST Fri Jan 9 2026

.WHAT HAS CHANGED...
Forecast remains in good shape with few wholesale changes at this 
time. That said, be aware of black ice this morning and areas of 
freezing fog. Light rain showers expected tonight, more widespread 
rainfall Saturday evening into Sunday. Growing potential for
localized freezing rain for northern portions of the higher
terrain Saturday night into early Sunday. Confidence is growing
for gusty west winds Sunday night into Monday.

&&

.KEY MESSAGES...

- Black ice and freezing fog possible this morning, followed by a 
mild and dry afternoon. Showery light rain tonight into tomorrow 
morning. 

- Another round of rain Saturday night into Sunday. Localized 
freezing rain possible for higher elevations of interior MA. 

- Cold front brings gusty west winds and cooler temperatures
  Sunday night into Monday.

&&

.DISCUSSION...
KEY MESSAGE 1...Black ice and freezing fog possible this
morning, followed by a mild and dry afternoon. Showery light  
rain tonight into tomorrow morning. 

1025mb high pressure is centered east of the Delmarva Peninsula and 
shifts northeast towards Nantucket early this morning, then shifting 
into the North Atlantic late tonight. Clear skies early this morning 
has allowed temperatures to fall below freezing, lingering moisture 
on untreated surfaces to refreeze and create slick conditions. The 
high shifts east of the Delmarva early this morning, leading to a 
return flow of light southerly wind. This ushers a relatively warmer 
airmass into southern New England. While it's not a slam dunk, there 
is potential for enough moisture to advect north to allow for areas 
of freezing fog to develop. Don't expect a widespread dense fog, 
thinking visibility restrictions are between 1-3 miles. Where there 
could be localized dense fog are those typical prone locations where 
cold air pools. Nevertheless, please drive safely this morning. Will 
have improvements between 8 AM and 10 AM as temperatures increase 
above the freezing mark. Mild afternoon with 925mb temperatures +4C 
to +6C, despite the cloud cover, afternoon highs reach the mid to 
upper-40s. Cannot rule out a few areas in southeastern Massachusetts 
touching 50F. Southerly flow increases during the afternoon, gusting 
20 to 25 MPH. 

Warm front lifts over southern New England this evening and tonight 
with showery rain possible. A widespread washout isn't expected. As 
mentioned previously, the best forcing is displaced well north, 
across northern New England and southern Quebec. Still, a few light 
rain showers arrive across western Massachusetts and Connecticut 
between 5 PM and 7 PM, then central and eastern Massachusetts and 
Rhode Island between 7 PM and 9 PM. Despite higher than normal PWATs, 
do not expect much QPF, once again due to lack of forcing. Rain 
totals range between 0.1" and 0.2". Showers exit off the coast 
between 12 AM and 3 AM Saturday as the trailing cold front pushes 
through the region. Not as cold, lows are in the middle to upper-
30s. Though, the Berkshires likely drop to the low-30s, here there 
would be a threat of black ice overnight. 

KEY MESSAGE 2...Another round of rain Saturday night into
Sunday. Localized freezing rain possible for higher elevations 
of interior MA. 

Cold front collapses south of the region early Sunday, becoming
quasi-stationary to the south of southern New England. This 
leads to drying conditions on Saturday, through at least the 
early afternoon before the next system moves in later on.

A more dynamic system will moves into the region Saturday
evening with a secondary surface low tracking across the
Cape/Island or just offshore. An enhanced SW jet will help 
transport above normal moisture into southern New England, 
around 230-280 percent of normal. This will set the stage for a 
soaking rain for southern New England. Rain will likely arrive 
in the afternoon spreading from south to north, tapering off 
early Sunday morning. Showers may linger across the south coast 
and Cape/Islands through the afternoon. There is still a decent 
range in QPF likely owing to track of the surface low. There 
continues to be a fairly wide range in the 25th-75th percentiles
among ensemble guidance. For northern MA amounts range from 
0.20- 0.50" and 0.40-1.0" for the south coast and Cape/Islands. 

We continue to monitor the potential for localized freezing rain 
across the northern high terrain. Light northerly flow with a colder 
airmass in place to the north may provide some drainage/weak cold 
air damming into terrain of northern MA later Saturday afternoon 
into Saturday night. Across model guidance, there is at least a weak 
signal that this colder air may be stubborn to scour out. Although 
some model solutions are more aggressive with the cold air than 
others. For now, opted to blend in a portion of cooler guidance
to account for the potential for the colder, around freezing 
temperatures. Surface temps around freezing and warm nose moving
in aloft will bring a marginal set-up for freezing rain
profiles. This is still lower probability due to the 
uncertainty in temperatures and how marginal they are to the 
freezing mark. Respectively the "higher" probabilities for 
freezing rain will be for the northern portions of the 
Berkshires followed by the northern portions of the Worcester 
Hills. Glaze to 0.10" can't be ruled out if the conditions end 
up favorable in those localized areas of the higher terrain. 
Since confidence is still on the lower end, held off on a Winter
Weather Advisory for now. 


KEY MESSAGE 3...Breezy to gusty westerly winds Sunday night into 
Monday. 

A cold front moves through late Sunday into Monday. Cold advection 
will help mix down at least a portion of the winds from a 850mb LLJ 
positioned across southern New England. This will result in a period 
of gusty west winds for southern New England Sunday night into 
Monday morning. Ensemble guidance shows potential for gusts 25-40 
mph with the highest gusts across the higher terrain and 
Cape/Islands. There are probabilities 60-80% for gusts greater than 
40 mph across the Berkshires. Probabilities drop off quickly after 
that, so a gust to 45 mph isn't out of the question. Into Monday 
afternoon gusts drop closer to 25-35 mph as the pres gradient 
relaxes. 

With the passage of the cold front Sunday night, a few snow showers 
or a weak snow squall are possible. Residual mid-level moisture, 
steepening lapse rates and incoming wind have led to some values in 
the snow squall parameter. Fields aren't particularly strong, but 
are sufficient for a weaker squall or two. Temperatures overnight 
drop into the 20s for most places. If there is any residual water 
from the rain over the weekend, this will freeze and bring slick 
conditions in spots for the Mon AM commute. 

Looking ahead to next week, cool and mainly dry early in the week 
with the pattern shifting more active mid-week onward with a few 
shots at precipitation.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

TAF Update: 12z


Today and Tonight... Moderate Confidence. 

Pockets of FG/BR this morning in CT Valley, south coast, and
Cape/Islands should dissipate from 12-15Z. VFR, becoming MVFR 
after 20z as a warm front approaches. South to south- southwest 
winds increasing, gusts 20 to 25 knots after 18z. Areas of SHRA 
move in from west to east 22z-00z, conditions briefly lower to 
IFR, showers diminish between 03-06z, improving back to VFR 
06-09z, while MVFR lingers on the Cape and Islands through 
09z-12z. Wind shifts to the west to west- northwest between 
04z-10z, winds speeds are 5 to 10 knots, slightly higher for 
coastal terminals.

Saturday... Moderate Confidence. 

VFR to start, then lowering to MVFR from south to north, along with 
showery rain, mainly after 18z/21z. Light north wind becomes east at 
5 to 10 knots. 

KBOS Terminal... Moderate Confidence. 

Low probability for light BR around the terminal 12-14Z. 

KBDL Terminal... Moderate Confidence.

MVFR to IFR visibility developing tonight, potential for dense fog 
and IFR ceilings 09z to 14z.

Outlook /Saturday Night through Tuesday/...

Saturday Night: MVFR/IFR conditions possible. RA, FZRA.

Sunday: Mainly VFR, with areas IFR possible. Breezy. Chance RA,
FZRA likely, chance SN.

Sunday Night: VFR. Windy with gusts up to 35 kt. Slight chance
RA, slight chance SN.

Monday: VFR. Windy with areas of gusts up to 30 kt. 

Monday Night through Tuesday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Saturday... High Confidence. 

Winds increases from the south on today as a warm front lifts over 
the region. Strongest gusts are over the outer ocean waters, 20 to 
25 knots this afternoon, then 25 to 30 knots overnight. Seas are 
increasing this afternoon and tonight 4 to 6 feet, localized areas 
of 7 feet on the outermost southern waters. Showery rain overnight, 
not expected to be at all impactful. Saturday morning winds go light 
and flip to the east as a quasi-stationary front lifts from the 
south to the north, rain accompanies this front as well during the 
early to midafternoon.

Outlook /Saturday Night through Tuesday/...

Saturday Night: Winds less than 25 kt. Local rough seas. Rain. 

Sunday: Low risk for Small Craft Advisory winds with local
gusts up to 30 kt. Areas of rough seas. Rain likely. 

Sunday Night: Strong winds with gusts up to 40 kt. Rough seas
up to 12 ft. Chance of rain. 

Monday: Strong winds with gusts up to 35 kt. Rough seas up to
12 ft. 

Monday Night through Tuesday: Low risk for Small Craft Advisory
winds with gusts up to 25 kt. Local rough seas. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 7 PM this evening to 3 AM EST 
     Saturday for ANZ235-237.
     Small Craft Advisory from 7 PM this evening to 7 AM EST 
     Saturday for ANZ250-254>256.

&&

$$

DISCUSSION...Dooley/Mensch
AVIATION...Dooley/Mensch
MARINE...Dooley/Mensch