Old Res Weather

Lexington, Massachusetts, USA

35°F

2/16/2025 7:17pm

Lexington Conditions: Clear
Temperature: 35.1°F / 1.7°C
Dew Point: 32.4°F
Relative Humidity: 90%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.00 in Falling Slowly
Visibility: 10 miles
Rain Today: 0.01 in
UV Index: $VPuv None

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 110605
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
205 AM EDT Tue Aug 11 2026

.WHAT HAS CHANGED...
Increased uncertainty regarding shower potential Wednesday.

&&

.KEY MESSAGES...

- Yet another very warm and humid day is expected today,
  followed by a gradual transition to cooler and drier
  conditions through the end of the work week. Much more
  comfortable weather is expected this weekend into early next
  week.

- Rain chances increase during the second half of the work week
  as a frontal boundary settles across the region, followed by a
  return to dry weather for the weekend. Rain chances may
  increase again early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Yet another very warm and humid day is expected 
today, followed by a gradual transition to cooler and drier 
conditions through the end of the work week. Much more comfortable 
weather is expected this weekend into early next week.

One more day of heat and humidity is on tap today, with 925mb 
temperatures of +20C to +23C supporting highs well into the middle 
to upper 80s. Dew points in the lower to middle 60s will make it 
feel warmer, with heat indices reaching the upper 80s to lower 90s. 
This will result in Moderate HeatRisk, particularly along the I-95 
corridor, with those most sensitive to heat and those without 
adequate cooling or hydration most susceptible to impacts.

The pattern begins to change Wednesday as temperatures aloft 
gradually cool, with 925mb temperatures falling from the lower 20s 
Celsius today into the teens Celsius by Friday. Dew points will 
follow suit, dropping from the 60s today into the 50s by late this 
week. The result will be a noticeably cooler and more refreshing 
airmass by Friday. A quasi-stationary front will be the primary 
driver of this transition. The front is expected to linger near 
southern New England late Wednesday into Thursday, keeping the 
region in a more unsettled pattern. As the front finally pushes 
offshore Friday, as a cold front, drier air will filter into the 
region behind it, aided by high pressure building southward from 
central Canada.

The weekend is shaping up to be the most comfortable stretch of 
weather in quite some time, with highs generally in the upper 70s 
across interior southern New England and lower 80s along the coastal 
plain. Dew points in the 50s will make for much more comfortable 
conditions, while overnight lows fall into the 50s Saturday and 
Sunday nights. These pleasant conditions may continue into early 
next week, although the forecast becomes more unsettled by then.

KEY MESSAGE 2...Rain chances increase during the second half of the 
work week as a frontal boundary settles across the region, followed 
by a return to dry weather for the weekend. Rain chances may 
increase again early next week.

Dry weather and a good deal of sunshine are expected today, although 
skies may become somewhat filtered by elevated smoke from distant 
wildfires. Tonight, a weak system passing south of New England could 
produce a shower or rumble of thunder across the extreme south coast 
and Islands, but probabilities remain low at less than 15 percent.

Wednesday remains a lower-confidence portion of the forecast. While 
most guidance keeps a fast-moving low pressure system south of New 
England, there are some notable differences in the guidance. The 00z 
NAM develops a robust 995 mb surface low near the Benchmark 
(40N/70W), while the 3 km NAM also depicts a surface low in the 
vicinity, though considerably weaker. AI guidance likewise maintains 
the surface wave south of New England. Given the overall consensus, 
the current forecast favors a track south of the region, with little 
to no precipitation expected during the day Wednesday. The forecast 
becomes more active Wednesday night into Thursday as a quasi-
stationary front settles across the Northeast. Weak surface lows 
riding along the boundary will provide multiple opportunities for 
showers, with precipitation chances increasing from late Wednesday 
night through Thursday night. While periods of showers are likely, 
the setup does not currently favor continuous rainfall across the 
region.

The front should finally push offshore early Friday, allowing drier 
air to move into southern New England as high pressure builds 
southward from central Canada. This will usher in the dry and much 
more comfortable conditions expected for the weekend. High pressure 
should remain the dominant feature through the weekend, supporting 
sunny to mostly sunny skies, low humidity, and seasonable 
temperatures. Beyond the weekend, the pattern becomes less settled, 
with increasing rain chances possible early next week as the next 
system approaches.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...

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

00z Update: No significant deviations from the prior forecast. Worth 
noting, high-resolution guidance suggests wildfire smoke from out 
west may lead to hazy conditions Tuesday afternoon, though 
confidence is lower regarding the potential impacts on terminals.

Today...High confidence.

VFR. West to west-northwest winds 8 to 12 kt. Winds across Cape Cod 
and the Islands will be west-southwest at 10 to 12 kt, with gusts up 
to 18 kt. As mentioned, there is a possibility for wildfire smoke to 
reach southern New England this afternoon and remain elevated, 
likely resulting in hazy skies and, at worst, visibility reductions 
to 5-6SM.

Tonight...High confidence.

VFR. Light and variable winds. There is a low probability for a 
shower to impact the Islands.

Wednesday...High confidence.

VFR. Light westerly winds. Potential for localized sea breezes to 
develop along the coast, including KBOS.

KBOS Terminal...High confidence.
Wildfire smoke aloft possible.

KBDL Terminal...High confidence.
Wildfire smoke aloft possible.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: VFR. 

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

Thursday Night: VFR. Slight chance SHRA.

Friday: VFR. Breezy. Slight chance SHRA.

Friday Night through Saturday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Wednesday...High confidence.

No significant weather expected through this period, with winds and 
seas remaining below advisory criteria. Winds today will be west to 
southwest, gusting at times to around 20 kt, especially across the 
waters south of Rhode Island toward Buzzards Bay and Vineyard Sound. 
Elsewhere, winds will be 10 to 15 kt. On Wednesday, localized sea 
breezes may develop near shore, while offshore winds remain variable 
at less than 10 kt. Seas will remain below 3 ft throughout the 
forecast period.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Winds less than 25 kt. 

Thursday: Winds less than 25 kt. Slight chance of rain showers,
isolated thunderstorms. 

Thursday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers. 

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

Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of seas approaching 5 ft. 

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

&&

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

&&

$$
Dooley