Lexington Weather

Lexington, Massachusetts, USA

71°F

7/25/2026 7:59pm

Lexington Conditions: Clear
Temperature: 70.9°F / 21.6°C
Dew Point: 51.3°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 251718
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
118 PM EDT Sat Jul 25 2026

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

&&

.KEY MESSAGES...

- Mainly dry conditions expected through the weekend with seasonable 
  temperatures. 

- Unsettled weather returns with periodic chances of scattered
  showers and thunderstorms early to mid week next week,
  potentially lingering into Thursday.

&&

.DISCUSSION...
KEY MESSAGE 1...Mainly dry conditions expected through the 
weekend with seasonable temperatures. 

The center of the surface high pushes offshore today shifting winds 
to the east. With weak high pressure still in place, expect another 
dry day with mainly sunny skies. Temperatures will be in seasonable 
ranges with highs in the low to mid 80s for the interior while 
onshore flow will keep the immediate coastal areas a little cooler 
(mid-upper 70s).

By Sunday, mid-level troughing arrives from west. Most guidance also 
indicates a low pressure system passing well offshore. There is 
still a signal across guidance low level moisture to advect in from 
offshore within the easterly flow. Model soundings indicate a 
shallow layer of moisture at the surface with dry air above. It is 
more likely that this layer will be too shallow to support any 
showers/drizzle. A worst case would be some patchy drizzle for the 
outer Cape/Islands. There is some question on if the moisture makes 
it far enough west to impact our eastern-most CWA, so this is still 
moderate confidence for now. Aside from the clouds in some areas, it 
will be a mainly dry day with a northeasterly breeze for the eastern 
coastal areas. Temperatures likely range in the low to mid 80s for 
the interior and mid to upper 70s in the eastern and coastal
areas. 

There will be an increased risk for rip currents Sunday due to
the prolonged period of easterly component flow. The risk spans
the south and east coastline with the greatest risk for the 
east-facing beaches along the Cape and Islands and portions of
the east coast of MA.

KEY MESSAGE 2...Periodic chances for showers and thunderstorms late 
Monday into Wednesday, potentially lingering into Thursday. Risk for 
localized heavy rainfall and flash flooding possible. 

A mid-level trough positions across the region through late-week. A 
series of shortwaves embedded in the flow are expected to progress 
across the region through the week supporting periodic chances for 
showers and thunderstorms mainly in the late Mon-Wed timeframe. 
Model guidance is struggling to come into agreement with the details 
of the pattern mainly with regard to the speed/position of the main 
trough and the potential for development of a closed low that tracks 
across the northeast. If this low develops, there are solutions that 
indicate an anomalously strong low for late-July. There is a strong 
signal for PWATs 120-170 percent of normal to advect into the region 
by Tuesday. If a low pressure develops, this would likely provide 
additional forcing and increase the risk for convection with 
localized heavy downpours thus bring in a risk for localized flash 
flooding. This all comes down to the tracking of the features which 
will dictate where the threat for the heavy showers/thunderstorms 
will be the highest. It is possible the threat ends up west or south 
of the region or confined to western portions of southern New 
England. This is something we will need to keep watching as model 
guidance comes into better agreement over the next day or two. This 
would likely fall in the late Monday through early Thursday 
timeframe with most guidance favoring development of showers and 
thunderstorms in a more diurnal cadence (afternoon/evening) with the 
support of daytime heating/instability. 

High temperatures will likely hover between normal and slightly 
below normal for the week.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

12z TAF Update...

Saturday night...Moderate confidence.

VFR for most. Very low chance of some marginal VFR/MVFR
conditions across Cape and Island terminals. Best chance would
be ACK after 05z. Otherwise, light and variable winds.  

Sunday...High confidence overall (Moderate for cigs in far
east).

VFR for most. Uncertainty in the potential for low clouds in
eastern MA and how far west they extend will be the main 
challenge. Greatest risk for Cape and Nantucket with MVFR 
ceilings possible. E winds for the interior 5-10 kts. NE winds 
for east coast terminals 8-12 kts. 

KBOS Terminal...High confidence in TAF. 

KBDL Terminal...High confidence in TAF.

Outlook /Monday through Thursday/...

Monday: VFR. 

Monday Night: VFR. Chance SHRA.

Tuesday: Mainly VFR, with areas MVFR possible. Breezy. Chance
SHRA, slight chance TSRA.

Tuesday Night: Mainly MVFR, with local IFR possible. Breezy.
SHRA likely, chance TSRA.

Wednesday: Mainly VFR, with areas MVFR possible. Breezy. SHRA
likely, slight chance TSRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Monday...High confidence.

Light winds and seas 1-4 ft today. Increasing winds and seas for
Sunday; however, likely below SCA. NE winds 8-12 kts with gusts
to 20 kts and seas 2-4 ft with 5 ft for the outermost southern
waters.  

Increased risk for rip currents Sunday with the greatest risk
for the east-facing beaches/coastline. 


Outlook /Monday 
through Wednesday/...

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

Monday Night: Winds less than 25 kt. 

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

Tuesday Night: Winds less than 25 kt. Seas up to 5 ft. Chance
of rain showers, chance of thunderstorms. 

Wednesday: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain showers, slight chance of thunderstorms.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents from 8 PM EDT this evening through 
     Monday morning for MAZ022.
RI...None.
MARINE...None.

&&

$$

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