Lexington Weather

Lexington, Massachusetts, USA

46°F

4/19/2026 8:02am

Lexington Conditions: Mist, Overcast
Temperature: 46.4°F / 8.0°C
Dew Point: 45.0°F
Relative Humidity: 95%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.73 in Falling Slowly
Visibility: 1½ miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 171952
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
352 PM EDT Fri Apr 17 2026

.WHAT HAS CHANGED...

While not set in stone, monitoring a weak area of low pressure 
Monday or Monday afternoon which could bring cloud cover and 
possible showers.

&&

.KEY MESSAGES...

- A few lingering showers are possible tonight. Cooler 
  and mainly dry for Saturday.

- Strong cold front brings a round of widespread showers 
  Sunday. Splashover possible for east coast during early Sunday
  morning high tide.

- Cooler than normal temperatures for Monday. Although generally
  dry weather is more likely, monitoring a weak area of low 
  pressure which could bring clouds and scattered showers. 
  Subfreezing low temperatures likely Monday night away from the
  cities.

- Brief return to seasonable temps on Wednesday, before cooling off 
 again into the latter part of the workweek.


.DISCUSSION...
KEY MESSAGE 1...A few lingering showers are 
possible tonight. Cooler and mainly dry for Saturday.

Surface low pressure moves offshore this evening with a few 
lingering showers possible. For remainder of the night, most places 
remain dry. Can't rule out a few showers or a sprinkle overnight 
along the east coast, Cape and Islands overnight with the wrap 
around moisture from the exited low and onshore flow. 

Cooler temperatures expected Saturday with cloudy conditions. 925mb 
temperatures drop 4-7 degrees from Friday and with cloudy skies 
should keep temperatures in the 50s and 60s. The warmer range of 
temperatures is most likely for the CT Valley while the onshore flow 
will keep temperatures cooler for the on/near the east coast. 
Easterly winds 5-12 mph. 

KEY MESSAGE 2...Strong cold front brings a round of widespread 
showers Sunday. Splashover possible for east coast during early 
Sunday morning high tide. 

A deep upper level trough shifts across the region Sunday into 
Monday. Ahead of it, anomalous moisture advects northward into 
southern New England. A strong cold front will push across the 
region through the day Sunday supporting widespread rain/showers. A 
few embedded thunderstorms or downpours are possible given the 
marginal instability. Not anticipating widespread flash flooding 
issues, at worst some ponding in poor drainage areas if there is an 
isolated downpour. As the cold front moves across Sunday late 
afternoon-evening, a cooler airmass advects in, reinforced with 
breezy NW winds. Can't rule out a rain/snow shower for the higher 
elevations if there are any lingering showers on the backside of the 
system. Not expecting any impacts/accumulation. 

The combination of steady east winds and higher astronomical 
tides raise the risk for splashover for the eastern coastal 
areas. Surge values range between 0.6-0.8 ft with astronomical 
tides forecast to be 11.6 ft. 

KEY MESSAGE 3...Cooler than normal temperatures for Monday. Although 
generally dry weather is more likely, monitoring a weak area of low 
pressure which could bring clouds and scattered showers. Subfreezing 
low temperatures likely Monday night away from the cities.

Upper level low with an anomalously cold pocket of air aloft still 
looks to govern Southern New England on Monday. While earlier 
guidance was indicating dry and blustery weather, there are some 
recent model forecasts (GFS-based, with a few Canadian ensemble 
members) which now show a surface trough or weak area of low 
pressure coming out of the lower Great Lakes early Monday and 
bringing clouds and scattered showers Monday or Monday afternoon. 
There isn't a large consensus of members which show this possible 
outcome, so it remains to be seen if this feature actually has legs 
or not. Current forecast shows some low chances for showers, and 
while the showers themselves might not be impactful (some which 
could be mixed with graupel pellets given cold profiles aloft), it 
will need to be watched with subsequent guidance as it would shift 
messaging from what was a mostly clear, blustery and cool day, to a 
cool and raw day with periods of showers. Highs only in the low to 
mid 40s in most areas, and if cloud cover does materialize, those 
values might be a few degrees cooler. Clearing by Monday night, with 
a near ideal radiational cooling setup looking likely as high 
pressure settles overhead. Widespread sub-freezing lows looks likely 
(20s to low 30s), except for the cities which run around the low to 
mid 30s.  

KEY MESSAGE 4...Brief return to seasonable temps on Wednesday, 
before cooling off again into the latter part of the workweek.

Although it looks like we'll get a brief rebound in temperatures on 
Wednesday closer to seasonable by Wednesday, our weather pattern 
still looks unsettled as a cold front moves through later Wednesday 
or Wednesday night, bringing rain showers. We then get a reinforcing 
shot of cooler air as northwesterly flow resumes, which should lead 
to temperatures trending near to below normal again for the latter 
part of the workweek.



&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

18z TAF update:

Today: Moderate confidence. 

Scattered showers and thunderstorms this afternoon with the
highest risk of a few thunderstorms for RI terminals (PVD)
through 20/21Z. Most showers diminish by 22Z. Ceilings mainly
MVFR with pockets of IFR possible. There is potential for brief
improvements to VFR (west and central terminals) and toward
MVFR/brief VFR for the eastern terminals (BOS). NE winds 6-12
kts. Gusts possible in and around any showers or storms (20-30
kts). 

Tonight...Moderate confidence (ceilings) 

Any lingering showers should dry up heading into tonight, can't
rule out a few showers/drizzle near Cape/Island terminals 
overnight. Light N to NE winds. Ceilings fall to MVFR/IFR with 
LIFR possible for the east to central terminals tonight with
periods of fog. 

Saturday...Moderate confidence (ceilings)

Ceilings straddling between MVFR and IFR during the day 
Saturday. Ceilings may struggle to improve out of LIFR for ACK,
but lower confidence. E/ENE winds 6-12 kts.  

KBOS Terminal...Moderate confidence in TAF.
Few showers possible through 21Z. Otherwise IFR to low-end MVFR.
There is potential for a period of improving ceilings around 00Z
where ceilings may improve to MVFR or even VFR briefly as the
low pressure exits offshore. This is lower confidence as NE
winds may be enough to re-develop the lower ceilings this 
evening. Low (IFR/LIFR) ceilings should most likely re-develop 
overnight tonight with MVFR/IFR ceilings during day Saturday. 


KBDL Terminal...High confidence in TAF.

Outlook /Saturday Night through Wednesday/...

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

Sunday Night: VFR. Breezy. Slight chance RA.

Monday: VFR. Breezy. Slight chance RA, slight chance FZRA.

Monday Night through Tuesday: VFR. 

Tuesday Night through Wednesday: 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.

Seas 2-4 ft and winds less than 25 kts out of northeast today
and Saturday. Localized 5 ft seas possible in the southern 
waters today; not expected to be persistent enough for Small 
Craft Advisories.  
 
Passage of stronger cold front Sun should bring SCA conditions 
to at least outer waters Sun into Mon. Wind gusts may locally
approach 25 kt late Sunday in the outer waters.

Outlook /Saturday Night through Wednesday/...

Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Rain showers likely. 

Sunday Night: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain. 

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

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

Tuesday: Winds less than 25 kt. 

Tuesday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers. 

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

&&

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

&&

$$

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