Lexington Weather

Lexington, Massachusetts, USA

84°F

5/27/2026 3:52pm

Lexington Conditions: Partly cloudy
Temperature: 83.8°F / 28.8°C
Dew Point: 61.5°F
Feels Like: 84.4°F
Relative Humidity: 47%
Wind: S 1 mph, 10-min avg: Calm, gust: 2 mph
Barometer: 29.62 in Falling Slowly
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 261721
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
121 PM EDT Tue May 26 2026

.WHAT HAS CHANGED...
No significant changes to the forecast.

&&

.KEY MESSAGES...

- Warm and pleasant conditions today.

- Hotter on Wednesday before a bit of a cool down Thursday into 
Friday. Slight risk of isolated afternoon showers/t-storms Wednesday 
afternoon and showers Thursday afternoon. 

- Temperatures trend near or below normal heading into the weekend 
 as rain chances return.

&&

.DISCUSSION...
KEY MESSAGE 1...Warm and pleasant conditions today.

Big improvement in the near term forecast compared to the dreary 
holiday weekend we just left behind. This, as southern New England 
is placed beneath largely zonal mid-level flow with surface high 
pressure to start on Tuesday. Subsidence and a much drier airmass 
(PWATs down near 0.5" briefly) will give us a dry Tuesday with 
plenty of sun filtered through high cirrus. Warm advection in the 
low/mid layers coincident with good mixing to near 850 mb will push 
high temperatures back into the 80s. For reference, normal highs 
this time of year are in the upper 60s to mid 70s. 

KEY MESSAGE 2...Hotter on Wednesday before a bit of a cool down 
Thursday into Friday. Slight risk of isolated afternoon showers/t-
storms Wednesday afternoon and showers Thursday afternoon. 

Further low level warm advection Wednesday pushes temps into the mid 
to upper 80s while moisture advection kicks in with dewpoints rising 
well into the 60s, especially along the south coast. This 
contributes to a decent amount of instability (focused again over 
the south coast) with 1000+ J/kg CAPE while low level lapse rates 
are 6-7.5C/km; limitations, however, include drier air in the mid 
levels and poor mid level lapse rates which would limit updraft 
development. Even so, given a cold front dropping through providing 
some lift, can't rule out some scattered showers and thunderstorms 
in the afternoon and evening if frontal timing is right. Behind that 
front on Thursday the airmass is cooler as the first in a series of 
shortwaves rounds the base of an eastern Canada trough directly over 
SNE. This means cooler temps (highs in the 70s) and little to no 
instability, so while some diurnal showers are expected, 
thunderstorms aren't a risk. 

KEY MESSAGE 3...Temperatures trend near or below normal heading into 
the weekend as rain chances return.

A deeper, cut-off low then rounds the base of the previously 
mentioned trough in the Friday night/Saturday time period which 
would bring an unusually cold airmass overhead depending on how deep 
it ends up being. Still uncertain as to how cool and wet this 
system is in SNE but models are in agreement with the occurrence of 
the deep trough, if not the exact placement and who gets a bulk of 
the wet weather. Ensemble guidance continues to favor northern New 
England for the wettest weather. Not seeing a quick improvement in 
this cooler/unsettled pattern in New England early next week as the 
synoptic pattern features a decent omega block well into the 
extended forecast period.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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 TAF. 

VFR. Sea-breeze diminishes 21-22Z with winds flipping back to
southwest at BOS.

Tonight...High Confidence

VFR. Light southwest winds. Some fog/low stratus possible near
the south coast which could support a brief period of MVFR/IFR
conditions at Cape/Islands terminals. 

Tomorrow...High Confidence

VFR. West winds 5-10 knots. Low risk for afternoon -SHRA/-TSRA
mainly over CT, RI, and Cape/Islands terminals. Best chances
would be after 21Z. Confidence not currently high enough to
include PROB30 group in TAF. MVFR/IFR stratus/fog at ACK.

Tomorrow Night... High Confidence.

Winds flip to the north/northwest between 03-06Z Thursday behind
a cold front. This will push out any fog/low stratus over The
Islands termianls. VFR elsewhere with north/northwest wind 5-10
knots. 

KBOS...High confidence in TAF.

KBDL...High confidence in TAF.

Localized fog remains possible early this morning, though 
confidence in occurrence and exact timing remains moderate.

Outlook /Wednesday Night through Sunday/...

Wednesday: VFR. Breezy. Isolated SHRA, isolated TSRA.

Wednesday Night: VFR. Isolated SHRA.

Thursday: VFR. Breezy. Isolated SHRA, isolated TSRA.

Thursday Night through Friday: VFR. Slight chance SHRA.

Friday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.

Saturday: Mainly VFR, with areas MVFR possible. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Wednesday...High confidence.

Marginal Small Craft Advisory conditions continue this morning 
across the outer ocean waters, with seas of 4 to 6 ft. These 
seas gradually subside by daybreak, followed by tranquil 
boating conditions through Wednesday, with seas mainly 2 to 4 
ft. Winds remain light and somewhat variable on Tuesday as high 
pressure moves overhead. By Wednesday, winds become more 
southwesterly around 15 kt, with occasional gusts up to 20 kt 
possible over the nearshore waters south of the coast. Both 
Wednesday and Thursday afternoons feature the chance for 
isolated pop-up showers or thunderstorms, though a washout is 
not expected.

Outlook /Wednesday Night through Sunday/...

Wednesday Night through Thursday: Winds less than 25 kt.
Isolated rain showers, isolated thunderstorms. 

Thursday Night through Friday: Winds less than 25 kt. Slight
chance of rain showers. 

Friday Night: Winds less than 25 kt. Chance of rain showers. 

Saturday: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.

&&

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

&&

$$

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