Lexington Weather

Lexington, Massachusetts, USA

37°F

1/11/2026 11:31am

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 081123
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
623 AM EST Thu Jan 8 2026

.WHAT HAS CHANGED...
No significant changes to the forecast. Patchy black ice this 
morning and then potential for freezing fog tomorrow morning. A 
chance of light rain Friday night, but a more robust system arrives 
Saturday night into Sunday with widespread rain and gusty wind.

&&

.KEY MESSAGES...

- Patchy black ice this morning. Fog or freezing fog tonight
  into Friday morning. Light rain overnight Friday. 

- Another round of rain later Saturday into Sunday bringing
  mainly a soaking rainfall to southern New England. 

- Breezy to gusty west winds Sunday night into Monday.

&&

.DISCUSSION...
KEY MESSAGE 1...Patchy black ice this morning. Fog or freezing fog 
tonight into Friday morning. Light rain overnight Friday. 

High pressure builds south of the region tonight. Will have dry but 
cold conditions with temperatures lowering into the low-30s and 20s. 
Lingering moisture from Wednesday will lead to slick surfaces if 
left untreated, an SPS highlighting the threat of black ice remains 
in effect through 9 AM. Motorist and pedestrians should use caution 
heading out either tonight or Thursday morning. Conditions improve 
midmorning as temperatures rise above freezing. As for the rest of 
Thursday, fairly quiet conditions with mid-level height rises and 
high pressure building near the Mid-Atlantic coast. Warm air 
advection supports milder a milder airmass, with afternoon highs 
ranging between 40F-45F. With high pressure and drying aloft, will 
have partly to mostly clear skies. Surface high pressure centered 
south of the region, with WAA cannot rule out patchy fog. Given the 
surface temperatures are below freezing, patchy freezing fog is 
possible late tomorrow night into Friday morning. Increasing 
southwest winds aloft bring in warmer conditions, 925mb temperatures 
rising between +4C to +6C Friday afternoon. Despite the cloud cover, 
afternoon highs reach the middle to upper 40s. Cannot rule out a few 
areas in southeastern Massachusetts touching 50F. A warm front lifts 
over southern New England Friday night into early Saturday morning, 
showery activity is possible, but a widespread washout isn't in the 
cards, mainly a tenth to two tenths of new precipitation. PWATs are 
well above climatology, but the best forcing is displaced further to 
the north across northern New England, with the parents low pressure 
system. No issues here with temperatures Friday night in the low-40s 
at the coast and upper 30s across interior locations. 

KEY MESSAGE 2...Another round of rain later Saturday into Sunday bringing
mainly a soaking rainfall to southern New England. 

By Saturday morning, Friday's system will be exited to the east 
along with the bulk of the rain showers. A few showers may linger 
along the south coast and Cape/Islands in the morning. 

The approaching system will be better synoptic support than Friday's 
system, consisting of deep, closed-off mid-level trough coupled with 
a southwesterly upper level. Model guidance has been consistent with 
showing developing of a secondary surface low offshore that tracks 
northeast around Cape/Islands 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 
another round of rain with more rain expected to fall compared to 
the late Friday system. Smaller details such as the exact track of 
the surface low and timing are still less certain due to subtle 
difference among model guidance. Rain will likely arrive in the 
afternoon, late morning at earliest for the south coast. Rain 
continues Saturday night, tapering off Sunday morning. Showers may 
linger across the south coast and Cape/Islands through the 
afternoon. For total rain, ensembles show a likely range of 0.50-1" 
with the higher end of that range favored for the south coast, 
southeast MA, and Cape/Islands. The axis of higher amounts shifts a 
little from run to run owing to the uncertainty in the low track. 
Upper percentiles of ensemble guidance show potential for amounts up 
to 1.5" for the Cape/Islands.

One thing that will need to be monitored will be temperatures across 
the northern parts of the interior Saturday night. A cooler airmass 
will be in place behind the morning cold front and warm air aloft 
will be pushing in from the south with the precipitation. If 
temperatures end up cold enough, this would result in a brief period 
of freezing rain at onset Saturday night. There are subtle 
differences among the global models on temperatures and we'll have 
to wait to get in higher-res guidance. Overall, if it ends up cold 
enough this would be fairly isolated and confined to the northern 
Berkshires and north Worcester Hills. 


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

A cold front moves through later Sunday into Monday. A tightened 
pressure gradient behind the exiting low pressure, moderate westerly 
LLJ, and some CAA will support gusty west winds Sunday night into 
Monday. The set-up isn't favorable for high winds, but is sufficient 
to support gusts 25-40 mph with the higher gusts over the higher 
terrain.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Forecaster Confidence Levels...

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

12Z TAF update...

Today... High Confidence. 

MVFR cigs in western MA and CT this morning are expected to
erode by 12Z. Otherwise VFR today. WNW winds 6-10 knots. A deck
of SCT-BKN clouds possible in western MA and CT this afternoon,
should most likely be VFR. 

Tonight... Moderate Confidence. 

VFR ceilings, potential for fog or freezing fog with visibilities 
lowering 3SM to 5SM. South wind less than 5 knots. 

Friday... Moderate Confidence (timing of lowering ceilings). 

VFR, trending to MVFR by midafternoon as a warm front approaches. 
Showery rain possible around and after 00z.

KBOS Terminal... High Confidence. 

VFR today. West-northwest wind around 10 knots, decreasing after
20Z to less than 8 kts. Potential for patchy light fog tonight
into Friday morning. 

KBDL Terminal... High Confidence.

VFR today, potential for fog or freezing fog tonight into Friday
morning.

Outlook /Friday Night through Monday/...

Friday Night: Mainly VFR, with areas IFR possible. Breezy.
Chance SHRA, patchy FG.

Saturday: Mainly VFR, with areas MVFR possible. RA.

Saturday Night: Mainly MVFR, with areas IFR possible. Breezy.
RA.

Sunday: Mainly VFR, with local IFR possible. Breezy. Chance RA.

Sunday Night through Monday: VFR. Windy with local gusts up to
30 kt. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Friday... High Confidence. 

High pressure exits the Mid Atlantic Coast this morning and moves to 
the waters south of southern New England. Wind & gusts remain light 
today, residual seas of 4 to 6 feet across the southern outer waters 
are the basis for a continued Small Craft Advisory through early 
this afternoon. A lull over the waters tonight, wind increases from 
the south on Friday as a warm front lifts over the region. Gusting 
between 20 to 25 knots and seas increasing 4 to 6 feet by Friday 
night.

Outlook /Friday Night through Monday/...

Friday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Chance of rain showers,
patchy fog. 

Saturday: Winds less than 25 kt. Areas of seas approaching
5 ft. Rain. 

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Local rough seas. Rain. 

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

Sunday Night: Strong winds with gusts up to 35 kt. Rough seas
up to 12 ft. Slight chance of rain. 

Monday: Strong winds with gusts up to 30 kt. Areas of rough
seas. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 AM EST this morning for ANZ250.
     Small Craft Advisory until 1 PM EST this afternoon for 
     ANZ254>256.

&&

$$

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