Lexington Weather

Lexington, Massachusetts, USA

44°F

4/22/2026 10:29am

Lexington Conditions: Overcast
Temperature: 43.7°F / 6.5°C
Dew Point: 37.0°F
Relative Humidity: 77%
Wind: Calm, 10-min avg: Calm, gust: 4 mph
Barometer: 30.12 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 161822
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
222 PM EDT Thu Apr 16 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- Backdoor front returns once again, making it cooler near the
  coast with continued warmth inland through Friday. Next chance
  for showers and thunderstorms tonight.

- Strong cold front moves through on Sunday bringing showers, 
  perhaps ending as brief snow showers but of no impact. 
  Blustery and anomalously cool temperatures for early to mid 
  next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Backdoor front returns once again, making it 
cooler near the coast with continued warmth inland through 
Friday. Next chance for showers and thunderstorms tonight.

Unseasonably warm temperatures aloft persist through the latter
half of this week, and a stronger shortwave approaches later 
tonight. The backdoor front that has been lingering around the 
region will dip back down again today, cooling the coast and 
ushering in more onshore flow. This front may make it as far 
inland as Worcester today, with temperatures further inland 
remaining much warmer. Highs in the low to mid 80s are possible 
once more out in the CT Valley, parts of RI, and western MA. 
Closer to the coast, highs will likely top out in the 50s, 
increasing up to the low 70s as you move inland. This backdoor 
front should exit the region as its associated low moves 
offshore through the day Friday, and flow shifts more W 
initially as a separate front pushes through the region, then 
shifts more onshore for the afternoon/evening.

With regards to the approaching shortwave, rain showers with  
embedded thunderstorms are possible once again tonight after
sunset. The latest forecast soundings have not changed much, 
still indicating 0-6 km bulk shear at and above 40 knots, and 
mid-level lapse rates around 6 C/km. The greatest instability 
remains over western MA and CT with MLCAPE values around 
1000-1500 J/kg with a window of surface-based CAPE in the late 
afternoon/early evening possibly overcoming CIN. Generally, 
though, most instability will be more elevated. So, the severe 
risk remains low, especially with LCL heights remaining above 
1000 km. This area is still under a Marginal (level 1 out of 5) 
risk for severe weather today, so remain weather aware this 
evening.


KEY MESSAGE 2... Strong cold front moves through on Sunday 
bringing showers, perhaps ending as brief snow showers but of no 
impact. Blustery and anomalously cool temperatures for early to 
mid next week.

A strong cold front will be working its way through the
Northeast on Sunday, acting on a narrow but moist (PWATs around 
1.2-1.4") warm sector. Showers, perhaps with a rumble or two of 
thunder, are likely with the front, which moves through during 
the daytime hours. The main story is what lies behind it:
an anomalously cool airmass with 925 mb temps dropping to near 
0C and 850 mb temps 0 to -5C by Sun night. Global models show 
the potential for backside snow showers as the front moves 
offshore; the airmass is just that cold where it is possible, 
but it remains to be seen if there is enough lingering precip as
the colder air surges in behind the front to allow for 
snowflakes to mix in. No impacts with those snow showers were 
they to develop though. 

While dry, Monday looks blustery and anomalously cool for mid-
April, with 925 mb temps around 0 to -2C, with northwest winds
around 10-15 mph and gusts 25-30 mph. High temps in/around the 
high terrain in the low to mid 40s, with mid to upper 40s for 
eastern MA and RI. Winds decrease later in the day with clear 
skies, light winds setting stage for a pretty chilly night with 
subfreezing lows in most areas away from the cities. Anomalously
cold air then begins to briefly recover starting Tuesday, 
though some indication for another weak disturbance in NW flow 
to reinforce another shot of cool air around midweek.

&&

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

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

Through 00z Friday: High confidence overall, though is low to 
moderate for Boston.  

Mainly VFR. Stratus and mist still lurks offshore and is hugging the 
eastern MA coastline and could at times work its way back into BOS 
but it may not be that persistent, if it even does so at all thru 
00z. Pop-up showers could develop near BDL and north of ORH as soon 
as 22z but would be more likely after 00z. SSW winds around 5-10 kt, 
with ENE/E winds for ORH, BED and BOS, with SE winds around 5 kt. 

Tonight: Moderate confidence. 

Mainly VFR; uncertain if BOS and BED see IFR/MVFR stratus layer 
return but would be more likely tonight as the boundary layer cools 
off. Couple periods of SHRA/possible TS: one 00z-03z mainly N/W of 
ORH, with a somewhat better chance after 06z Fri. Carried PROB30s 
for the time being since the coverage could be spotty. SW winds (E 
winds near the eastern coast) around 5-10 kt become light in all 
areas thru midnight then should come around to light northerly by 
daybreak. 

Friday: Moderate confidence. 

Mainly MVFR, possibly IFR from low ceilings, with periods of 
hit-or-mostly-miss showers. North to northeast winds 5-10 kt.  

KBOS Terminal...Moderate confidence in TAF. VFR generally
governs thru 00z, but stratus and mist lurk offshore and could 
at times bring periods of IFR. Better chance at IFR stratus
coming in tonight. Mainly dry but risk for rain showers after
06z Fri. NE/E winds 5-10 kt flip to light southwest briefly 
overnight, then return to light northerly for Friday.

KBDL Terminal...High confidence in TAF.

Outlook /Friday Night through Tuesday/...

Friday Night through Saturday: Mainly VFR, with local MVFR
possible. 

Saturday Night: Mainly VFR, with areas IFR possible. Breezy.
Slight chance SHRA.

Sunday: Mainly VFR, with local IFR possible. Breezy. SHRA
likely.

Sunday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SHRA, slight chance SHSN.

Monday: VFR. Breezy. Slight chance SHRA, slight chance SHSN.

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence through the weekend.

Backdoor front meandering over southern New England through Fri
morning will maintain light winds and calm seas, though there
will be wind shifts from SW to NE from time to time on eastern
MA waters along with showers and embedded thunderstorms. Brief
periods of marginal Small Craft Advisory seas possible late
tonight/early Fri AM over the southern outer waters, though not 
expected to be widespread.
 
Passage of stronger cold Front Sun should bring SCA conditions
to at least outer waters Sun into Mon.

Outlook /Friday Night through Tuesday/...

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

Saturday through Saturday Night: Winds less than 25 kt. 

Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Rain showers likely. 

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft. Chance of
rain showers. 

Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers, slight chance of snow showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

DISCUSSION...Loconto/Hrencecin
AVIATION...Loconto/Mensch
MARINE...Loconto/Hrencecin