Lexington Weather

Lexington, Massachusetts, USA

50°F

4/19/2026 1:17pm

Lexington Conditions: Light rain, Mist, Overcast
Temperature: 49.8°F / 9.9°C
Dew Point: 48.7°F
Relative Humidity: 96%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.71 in Rising Slowly
Visibility: 2½ miles
Rain Today: 0.02 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 160536
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
136 AM EDT Thu Apr 16 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- Backdoor front brings cooling near coast but warmth continues
  inland through Friday.

- Rounds of showers and thunderstorms this afternoon, later tonight,
  and again Thursday night.

- Pattern turns cooler early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Backdoor front brings cooling near coast but warmth 
continues inland through Friday.

Backdoor front dropping southward will bring cooler temperatures at 
least to eastern MA coast as winds turn onshore, but warmer 
temperatures will persist inland. Front itself should meander over 
southern New England for next couple of days, probably settling near 
a line from Fitchburg to Norwood and Plymouth later this afternoon, 
retreating back north overnight, then dropping back southward again 
Thursday afternoon to about the same location. This certainly 
presents a big challenge with the temperature forecast, less so in 
CT and western MA which are more likely to maintain summertime 
warmth through Friday, but less so across RI and eastern MA 
depending upon exactly where front ends up and with its timing.


KEY MESSAGE 2...Rounds of showers and thunderstorms this afternoon, 
later tonight, and again late Thursday.

As front remains over or near southern New England, a series of weak 
low pressure centers will ride along it, each bringing chances of 
showers and embedded thunderstorms.

First round through early tonight looks to be more scattered in 
nature per high-res guidance. Already seeing CU development
upstream across central NY where instability is increasing so
that is where convective initiation should take place. 

Environment here will feature strong 0-6km shear and reasonably
strong mid level lapse rates (6C/km) but best instability (1000
J/kg) is focused over western MA/CT which makes sense given 
that is the area to the west of the front. While we don't expect
to see as much activity as we did Tuesday evening, there could 
still be a few storms between 4 PM and 8 PM, perhaps even a few 
hours later than that, capable of producing wind damage, 
especially in CT per HREF helicity swaths.

Farther east in the cooler airmass, there is virtually no surface 
instability but perhaps enough instability aloft coupled with 
heating to pop up a few brief showers. 

Next round of showers and embedded thunderstorms arrives during the 
overnight hours ahead of weak short wave and weak surface low riding 
along front. We still have strong 0-6km shear and decent mid level 
lapse rates approaching 7C/km, but instability is aloft and would 
support more in way of elevated thunder, not surface based, so 
overall severe threat is low.

Once low moves offshore, it should drop front southward Thu morning 
before it retreats northward again in afternoon. We then remain 
under large scale subsidence until next stronger short wave 
approaches Thu night. Environment remains about same with greatest 
instability west of I-91 but continued presence of strong 0-6km 
shear and decent mid level lapse rates of 6-7C/km. Guidance shows 
showers and thunderstorms forming to out west during the day, which 
arrives here Thu night and weakens as it does so.


KEY MESSAGE 3...Pattern turns cooler early next week.

It's been said all good things must come to an end, and for
those who have been enjoying this early taste of summer, a brief
pattern change will bring a return to much cooler weather early
next week.

A strong cold front crosses southern New England Sun followed 
by a deep upper trough rotating through region, bringing an 
anomalously cold airmass back into the region, albeit for a 
short time. Temperatures aloft drop to as low as -7C to -10C at
850 mb Mon morning, only supporting highs in 40s and 50s Mon. 

It might not be want you want but high pressure covering much of
eastern U.S. eventually shifts offshore by midweek as upper 
flow becomes more zonal, allowing for a slow warming trend. 
Highs should get back into 60s by Wed.

&&

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

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

06Z Update...Moderate confidence.

Today and Tonight:

Scattered showers with embedded thunderstorms continue to move
east across the region this morning amidst a mix of LIFR to VFR
ceilings. VFR to MVFR ceilings possible in any RA/TSRA that
moves through with visbys to IFR not ruled out in any heavier
showers/storms. The main line pushing through should exit the
region in the next 2 hours or so. Another line of showers
following it will progress through over the next few hours as
well.

For the day today, improvement to VFR expected for most 
terminals, aside from western MA and central CT. Some may remain
MVFR through much of the day, but periods of more scattered
ceilings may give way to VFR midday in any areas where
persistent MVFR is possible. SW winds today with E/NE winds to 
start closer to the coast. More scattered showers and storms
possible again tonight.

Friday:

VFR with periods MVFR. Showers and thunderstorms possible. Winds
shifting from the W/NW to NE as the day goes on.

KBOS Terminal... Moderate confidence in TAF. Though MVFR 
possible though most of today, periods of VFR possible if 
ceilings end up more SCT than BKN.

KBDL Terminal... High confidence in TAF.

Outlook /Friday through Monday/...

Friday: VFR. Chance SHRA, slight chance TSRA.

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

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

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

Sunday Night: VFR. Breezy. Chance SHRA.

Monday: VFR. Breezy. Slight chance SHRA.

&&

.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 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.

Passage of stronger cold Front Sun should bring SCA conditions to at 
least outer waters Sun into Mon.

Outlook /Friday through Monday/...

Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers. 

Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain showers. 

Saturday: Winds less than 25 kt. 

Saturday Night: Winds less than 25 kt. Slight chance of rain
showers. 

Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers. 

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

Monday: Winds less than 25 kt. Local rough seas. Slight chance
of rain showers.

&&

.CLIMATE...
Today's record highs (April 15):

Boston 82 in 1896
Hartford 88 in 1941
Providence 82 in 1938
Worcester 85 in 1941

&&

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

&&

$$

DISCUSSION...JWD
AVIATION...KJC/Hrencecin/JWD
MARINE...JWD
CLIMATE...