Lexington Weather

Lexington, Massachusetts, USA

71°F

7/25/2026 8:01pm

Lexington Conditions: Clear
Temperature: 70.7°F / 21.5°C
Dew Point: 51.1°F
Relative Humidity: 50%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.99 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 220753
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
353 AM EDT Wed Jul 22 2026

.WHAT HAS CHANGED...
Small Craft Advisories extended through tonight (northern
waters) and through Thursday (southern waters). 

&&

.KEY MESSAGES...

- Warmer and drier for the most part today with the chance for 
  isolated showers and thunderstorms in the afternoon. 

- Mainly dry with seasonable temperatures Thursday through the 
  weekend. 

&&

.DISCUSSION...
KEY MESSAGE 1...Warmer and drier for the most part today with 
the chance for isolated showers and thunderstorms in the 
afternoon. 

The high coverage showers and thunderstorms have cleared southern 
New England early this morning. However, a second batch will push 
into the south coast, far southeast MA/Cape & Islands after 4 AM 
continuing through the early morning hours. Other areas will remain 
dry; however, residual high dewpoints and recent rainfall have 
supported patchy fog this morning. Expect conditions to improve 
through the morning with breaks of sun developing from west to east. 
Temperatures rise into the low to mid 80s in most spots. 

There is still the risk for showers and thunderstorms this 
afternoon. A cold front approaches from the west bringing a push of 
higher dewpoint air out ahead of it. With the added heating, 
instability should likely build through the afternoon with SBCAPE 
values 1000-1800 J/kg. Model guidance has been more consistent with 
showing clearing early enough to support the building instability. 
The moisture and instability are sufficient to support development 
of showers and thunderstorms as the cold front progresses eastward. 
With 0-6 km shear 30-40 kts, the environment is supportive of 
organized convection with potential for an isolated strong to severe 
storm or two. Profiles will not be nearly as saturated as last night 
with model soundings showing plentiful moisture at the surface, but 
also dry air in the mid-levels. In some cases this can limit 
convection. The high-res CAMs have generally exhibited isolated 
coverage of showers and thunderstorms this afternoon, so most places 
will stay dry. Despite this, it is still possible for a strong to 
severe storm in the mix given the supportive environment. Main 
threat would be locally damaging gusts. Showers and thunderstorms 
likely develop mid to late afternoon from west to east with any 
lingering showers/storms exiting offshore early tonight. 

A cold front sweeps through tonight with winds shifting to the 
northwest ushering in drier air and cooler temperatures.

KEY MESSAGE 2...Mainly dry with seasonable temperatures Thursday
through the weekend. 

The cold front pushes offshore by Thursday while an upper trough 
tracks across the northeast. High pressure gradually builds in from 
the west supporting a period of dry conditions. 925mb temperatures 
generally range 16-20C support seasonable temperatures in the low to 
mid 80s through the weekend. Ensembles lean toward keeping the 
region dry through the weekend with a transition to a more unsettled 
pattern with rain chances early next week. 


&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

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

06Z Update...

Through 12Z...Moderate confidence.

Another batch of showers pushes into the Cape and Islands 08-12Z
otherwise mainly dry for remaining terminals outside of a stray
shower. Ceilings will be tricky early this morning with
terminals hovering from LIFR to IFR with some terminals briefly
scattering out. Leaned toward keeping the lower ceilings in
early this morning with patchy fog possible. Winds S/SSW winds
8-12 kts. Gusts for Cape/Island terminals 20-25 kts.  

Today... Moderate confidence. 

IFR ceilings scatter out to VFR across the interior extending
eastward through the morning. IFR/MVFR ceilings lingering over 
the Cape/Islands terminals into the afternoon. Confidence
moderate on exact timing of improvements to VFR. Showers and 
thunderstorms possible after 18Z, though isolated in coverage. 
Due to low coverage and uncertainty in intensity of 
showers/storms, kept as PROB30s for TSRA. SW winds 10-15 knots 
with gusts 20-25 kts. 

Tonight...High Confidence. 

Any afternoon SHRA/TSRA wanes after 00Z. VFR conditions tonight. 
Winds shift to WNW/NW at 5-10 knots behind a passing cold 
front between 22-03Z. 

KBOS Terminal...Moderate confidence in TAF. 

Uncertainty in the exact timing of improvement in ceilings to
VFR, but most likely between 14-16Z. Lower confidence with the
potential for showers/thunderstorms this afternoon, mainly due
to the isolated nature of showers/storms. Included a PROB30 for
now to TSRA with the most likely timeframe being between 20-01Z. 

KBDL Terminal...Moderate confidence in TAF.

Highest chances for TSRA between 21-00Z.

Outlook /Thursday through Sunday/...

VFR. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight through Thursday

Small Craft Advisories remain in effect for SW winds 10-20 kts
with gusts 25-30 kts and 6-10 foot seas for the outer coastal 
waters and southern waters. Highest waves are expected over the 
south coastal waters. Isolated showers and thunderstorms 
possible early tonight. 

A cold front crosses the waters tonight resulting in a wind 
shift to the NW. Winds and seas will slowly decrease overnight
across the northern waters. Seas will be the slower to decrease,
especially across the southern waters. Extended SCAs through
Thursday for south and east coastal waters. They may need to be
extended further (through Fri AM) for southern outer waters
because of 5 ft seas.  

Outlook /Thursday through Sunday/...

Thursday: Winds less than 25 kt. Areas of rough seas. Chance of
rain showers. 

Thursday Night: Winds less than 25 kt. Seas up to 5 ft. 

Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. 

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

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Surf Advisory until 8 PM EDT Thursday for MAZ020>024.
RI...High Surf Advisory until 8 PM EDT Thursday for RIZ006>008.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ231.
     Small Craft Advisory until 2 AM EDT Thursday for ANZ232>234-
     250.
     Small Craft Advisory until 2 PM EDT Thursday for ANZ235-237.
     Small Craft Advisory until 8 PM EDT Thursday for ANZ254>256.

&&

$$

DISCUSSION...Mensch
AVIATION...Mensch
MARINE...Mensch