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 071849
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
149 PM EST Wed Jan 7 2026

.WHAT HAS CHANGED...
Forecast remains on track. Expect remaining -FZRA/-SN over
eastern MA to exit off the east coast by 1-2PM. Skies will
gradually clear from west to east overnight as high pressure
builds in from the west. High pressure will support quiet
weather with slightly above normal temperatures through Thursday
night. Still expect a period of above normal temperatures and
rainfall through the weekend. 

&&

.KEY MESSAGES...

- High pressure builds in from the west supporting quiet 
  weather through Thursday night.

- Impressive warm up Friday into the weekend before seasonable
  temps return Monday. 

- Rain late Friday through Sunday with a lull during the day on
  Saturday. 

&&

.DISCUSSION...

KEY MESSAGE 1...High pressure builds in from the west 
supporting quiet weather through Thursday night.

Precipitation ends early this afternoon. Cloudy/cold conditions
persist with skies clearing from west to east overnight. High
pressure builds in from the west overnight into tomorrow with
light winds and mostly clear skies. High pressure will support
overall quiet weather through Thursday night with lows tonight
in the mid to upper 20s, highs in the low-mid 40s tomomrrow, and
lows in the mid-upper 20s again Thursday night. More active
weather wattern for the weekend...see Key Message 2 for more
details.


KEY MESSAGE 2...Impressive warm up Friday into the weekend 
before seasonable temps return Monday. 

Put away the winter parkas, at least for a few days thanks to a big 
warm up arriving Friday with a surge of mild air beneath a building 
subtropical ridge. Besides moisture (more on that below) this will 
bring strong warm air advection in the low and mid levels; 925 mb 
temps surge from 0C Thursday to +9C Friday night into Saturday. This 
will put high temperatures each day through Sunday in the upper 40s 
to even low 50s! Climatology for this time of year is mid to upper 
30s. A strong, drying cold front will bring temps back in line to 
start next week with highs in those mid to upper 30s. 

KEY MESSAGE 3...Rain late Friday through Sunday with a lull 
during the day on Saturday. 

The Thu/Fri subtropical ridge is suppressed late Friday by the first 
in a series of shortwaves rounding the broad trough upstream. As the 
surface low passes through Quebec it drags its warm front north 
through New England. This and a 45-55 kt LLJ act on an airmass with 
PWATs of 1-1.25" leading to warm advection showers late Friday into 
Friday night before the cold front briefly sinks south and drier air 
brings precip to an end for a time during the day on Saturday. The 
exception would be the south coast, depending on how far south that 
front gets (low confidence on who if anyone sees a prolonged lull in 
the wet weather). Quickly though the following system once again 
pushes warm and moist air over SNE late Saturday into Sunday and 
this is a more dynamic system that wants to develop a secondary low 
over SNE helping to squeeze out much more rain with the Saturday 
night/Sunday round. When all is said and done, the south coast may 
see 1-1.5 inches of rain with amounts closer to 0-5-1 inch further 
north. Ensemble guidance indicates a 50-80% chance of AOA 1" of rain 
for the Cape and Islands, lesser odds elsewhere. A decent LLJ 
accompanies each of these disturbances but inverted temperature 
profiles should keep the damaging wind aloft with just breezy 
conditions Friday and Sunday/Sunday night. The trailing cold front 
then brings drier and colder weather to start next week.

&&

.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...High confidence in trends, moderate in timing


Last batch of showers moving over BED/BOS right now should exit
off the east coast between 18-19Z. Surface weather obs varying
between -SN or -FZRA. BOS currently reporting -FZRA, but a
changeover to -SN is very possible before precipitation exits,
thus used -FZRASN for prevailing group at BOS from 18-19Z.
Expect gradual improvements to MVFR between 20-23Z and
eventually VFR by 00Z. Light northwest winds from 5 to 10 knots.

Tonight... High Confidence. 

Mainly VFR, although MVFR may linger into the evening for 
Cape/Islands. WNW wind 5-15 kt.

Thursday... High Confidence. 

Dry. VFR. Light NW wind becomes W, less than 8 knots. Wind may 
become calm after 21z with high-pressure moving into the region. 

Thursday Night...High Confidence.

VFR. Light and variable winds.

KBOS Terminal... High confidence in trends

Expect conditions to gradually improve to VFR between 22-00Z.
-FZRA currently at terminal may changeover to -SN before precip
 exits east by 19Z.

KBDL Terminal... High confidence.

Outlook /Friday through Monday/...

Friday: Mainly VFR, with local MVFR possible. Breezy. Chance
RA.

Friday Night: MVFR/IFR conditions possible. Breezy. Chance RA.

Saturday: Mainly VFR, with local IFR possible. Breezy. RA.

Saturday Night: MVFR/IFR conditions possible. Breezy. RA.

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

Sunday Night: VFR. Breezy. Slight chance RA, slight chance SN.

Monday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Key Point:

- Small Craft Advisory in effect through Wednesday for the 
  southern waters and eastern outer waters for seas greater than
  5 feet.
  

Tonight through Thursday Night... High Confidence. 


Area of low-pressure exits east over the waters this afternoon
and evening. High pressure builds in from the west was drier
weather and modest northwest winds around 10 knots through
Friday morning. Seas remain near SCY levels for the southern and
outer marine zones before subsiding under high pressure tomorrow
afternoon.

Outlook /Friday through Monday/...

Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. Slight chance of rain.

Friday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Rain likely. 

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 local
gusts up to 30 kt. Areas of rough seas. Chance of rain. 

Sunday Night: Strong winds with gusts up to 35 kt. Areas of
rough seas. Chance of rain. 

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 1 AM EST Thursday for ANZ235-237.
     Small Craft Advisory until 7 AM EST Thursday for ANZ250.
     Small Craft Advisory until 1 PM EST Thursday for ANZ254.
     Small Craft Advisory until 1 PM EST Thursday for ANZ255-256.

&&

$$

DISCUSSION...BW/RM
AVIATION...BW/RM
MARINE...BW/RM