Lexington Weather

Lexington, Massachusetts, USA

75°F

7/13/2026 11:45pm

Lexington Conditions: Clear
Temperature: 74.5°F / 23.6°C
Dew Point: 62.8°F
Relative Humidity: 67%
Wind: Calm, 10-min avg: Calm, gust: 1 mph
Barometer: 29.99 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Southeast Middlesex County, MA - Heat Advisory
- SEE ALL NEARBY ALERTS -

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 090006
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
806 PM EDT Wed Jul 8 2026

.WHAT HAS CHANGED...
A Rip Current Statement is in effect through this evening for 
eastern and ocean facing beaches in Massachusetts. A Small Craft
Advisory remains in effect until 8 pm this evening.

&&

.KEY MESSAGES...

- Becoming warmer with increasing humidity through the end of 
  the work week.

- Warm, humid weather returns late in the week. Scattered
  showers and thunderstorms possible both days but better 
  chances looking to be on Friday.

- Drier, seasonably cool and less humid weather for the weekend
  into early next week

&&

.DISCUSSION...
KEY MESSAGE 1...Becoming warmer with increasing humidity 
through the end of the work week.

High pressure and mostly clear skies continue through most of 
Thursday. 925mb temperatures rising to near 20C and plenty of 
sunshine will allow for surface temperatures to begin to creep 
up above seasonable norms... likely near 90 across most of 
southern New England by Thursday. Humidity will begin to 
increase under broad WSW flow, with dewpoints increasing to near
or just above 70 (at times) Thursday. A cold front moving 
through Thursday evening could bring chances for isolated to 
scattered showers and thunderstorms later in the 
night/overnight, but the highest risk currently remains in 
western MA.

A Rip Current Statement has also been issued through this 
evening for eastern MA, primarily for ocean facing beaches, due 
to prolonged northeasterly flow and 5+ ft seas.


KEY MESSAGE 2...Scattered thunderstorms along a cold front 
Friday afternoon to early evening. Although severe weather 
potential looks minimal at this time, lightning and torrential 
downpours are the main risks.

Warm and humid weather continues into Friday to go along with 
partly to mostly cloudy skies. A cold front will be gradually 
sagging southward from northern New England during the early 
afternoon in northern MA and reaching the southern CT-RI-MA 
coastline by early evening. This will pose a better chance for 
scattered showers and thunderstorms to develop than compared to 
Thursday. 

The biggest uncertainties specific to the thunderstorm forecast
are the degree of instability we can muster and how quickly 
will the front progress offshore. Both the 12z NAM and 12z GFS 
capture the instability envelope well, with the NAM's CAPE 
values around 1500- 2500 J/kg due to its high-dewpoint bias, 
while the GFS's overmixing bias shows considerably lower values 
at around 500 J/kg or less. The answer is probably somewhere in 
the middle; shear values are also on the lower side at around 30
kt, which should mitigate or limit any organized severe weather
potential outside of water-loaded downdrafts. The main risks 
looks to be lightning and slow-moving heavy downpours, which 
could lead to instances of street flooding in areas that see 
repeated thunderstorms. Latest guidance indicates 700- 500 mb 
heights which become increasingly parallel to the southward- 
sagging frontal boundary, which adds to the risk for slower-
moving storms and also casts some uncertainty when we clear out,
with the Canadian guidance suggesting post-frontal light rains 
lingering into part of Saturday along the South Coast.

KEY MESSAGE 3...Drier, seasonably cool and less humid weather 
for the weekend into early next week.

Even if the cold front from Friday night takes a little bit 
longer to fully clear out from the South Coast, we should be 
trending drier by Saturday late morning. The 500 mb pattern then
transitions to one of cyclonic flow/troughing in the mean, 
which favors cooler temperatures (low to mid 80s) and lower 
humidity levels than experienced for late in the week. Weekend 
appears favorable for outdoor plans with nice summer weather. 
We'll be on the far western periphery of a pretty impressive 
upper level ridge which latest guidance still shows reaching to 
nearly 600 dm building over the northern/central Plains and 
upper Midwest. We still might need to keep an eye on possible 
storminess pivoting around the ridge but it looks as though the 
weekend into early next week ends up drier than not.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Forecaster Confidence Levels...

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

00Z TAF Update:

Wednesday night...High confidence. 

VFR. Light and variable winds becoming southwest.

Thursday...Moderate confidence. 

VFR. An isolated shower or thunderstorm is possible after 20Z 
across the western terminals.

Thursday night...Moderate confidence. Lowering clouds moving in with
areas of MVFR and possibly IFR.

KBOS Terminal...High confidence. 

KBDL Terminal...High confidence.

Outlook /Friday through Monday/...

Friday: VFR. Chance SHRA, chance TSRA.

Friday Night through Sunday Night: VFR. 

Monday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Friday Morning...High confidence.

SCA conditions continue in the the coastal waters through this 
evening with NE wind gusts around 25 kts. Conditions improve 
overnight into Thursday as high pressure builds over the region.
A weak front approaches the region later Thursday with showers 
and thunderstorms possible over the southern waters.

Outlook /Friday through Monday/...

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

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

Saturday through Saturday Night: Winds less than 25 kt. Areas
of seas approaching 5 ft. 

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

Sunday Night through Monday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents until 11 PM EDT this evening for MAZ007-
     014>016-019-022-024.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ250-
     254-255.

&&

$$

DISCUSSION...Loconto/McMinn
AVIATION...Loconto/McMinn/Birchfield
MARINE...Loconto/McMinn