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 101713
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
113 PM EDT Mon Aug 10 2026

.WHAT HAS CHANGED...
Forecast remains on track.

&&

.KEY MESSAGES...

- Above normal temperatures and humidity continues through
  Tuesday. Relief from the heat & humidity comes late week.

- Unsettled weather continues this week with shower and 
  thunderstorms chances returning this evening as well as 
  Wednesday night/Thursday morning.

&&

.DISCUSSION...
KEY MESSAGE 1...Above normal temperatures and humidity 
continues through Tuesday. Relief from the heat & humidity 
arrives for the weekend.

After a brief respite from the humidity this morning, dewpoints
will start climbing back into the upper 60s to low 70s once the
sun comes up. Temperatures should be a tad cooler today.... 
roughly 85-89 instead of the 90+ we've been seeing lately. 
Humidity will linger through Tuesday, but both temperatures and 
dewpoints will slowly begin to trend lower throughout the week, 
bringing much needed relief to southern New England by Friday. 
High temps heading into the weekend likely near 80 with 
dewpoints dropping into the 50s, possibly even the 40s in the 
higher elevations.

KEY MESSAGE 2...Unsettled weather continues this week with 
shower and thunderstorms chances returning this evening as well 
as Wednesday night/Thursday morning.

A passing cold pool across northern New England should help to 
generate CAPE values of 750-1,250 J/kg by late this afternoon. 
Combined with a one-two punch from a passing warm front and 
trough axis moving through southern New England, some scattered 
showers and thunderstorms could pop later this evening. CAM 
guidance is once again struggling to resolve these storms, with 
some models indicating storms over NW MA, others show W CT, and 
others still keep storms confined to the Albany/NYC metro 
regions. Confidence is on the lower end as far as timing and 
placement, but currently thinking late afternoon into the sunset
hours with highest chances for a strong to severe storm forming
along the CT River Valley. A few showers could stray as far 
east as the ORH-PVD corridor; however, if these showers move 
that far east, they should be sub- severe.

Tuesday and Wednesday should remain dry and mostly sunny, 
pleasant days. But by Wednesday night/Thursday morning, a low 
pressure system sitting over the Hudson Bay will be pushing 
south/southeast into southern Quebec and New England. A few 
associated upper-level shortwaves and a cold front will likely 
be the catalyst for another round of thunderstorm chances; 
however, the main limiting factor will be the time of day the 
front pushes through. If the front hits the eastern MA coast by 
early Thursday afternoon, we'd expect weaker instability and a 
lower thunderstorm risk. However, if the front stalls or moves 
slower, then the risk for storms would increase, and so would 
the chance for any one storm to reach severe levels.

&&

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

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

18z TAF Update: 

This afternoon: Generally high confidence, but moderate 
confidence on timing/probability of TSRA. 

VFR with hazy skies from higih level smoke possible. Winds SW 
5-10 kts. SHRA/TSRA look to develop late in the day, starting 
as soon as 21z at BDL with the higher risk after 23Z. Confidence
decreases in TSRA as the activity moves E/ESE toward ORH and 
further east terminals (00-05Z).  

Tonight: High confidence. 

VFR. Sea breeze at BOS kicks out 23-01Z with winds shifting to
SW. SW winds 5-10 kts shift to WSW/W overnight. 

Tuesday: High confidence. 

VFR. NW winds 10-15 kts. 

Tuesday night:High confidence. 

VFR. Winds light and variable. 

KBOS Terminal...Moderate confidence in TAF. 
Low probability for a SHRA/TSRA after 01-06Z. Too low to 
include in TAF at this time. 

KBDL Terminal...Moderate confidence in TAF. Wildfire smoke aloft possible.
Potential for scattered SHRA or a TSRA after 21z, but moreso
after 23Z. If any storms develop, a stronger storm is possible 
with gusty winds, frequent lighting, and brief IFR visbys.

Outlook /Tuesday Night through Saturday/...

Tuesday Night through Wednesday: VFR. 

Wednesday Night: VFR. Chance SHRA.

Thursday: VFR. Breezy. Chance SHRA, slight chance TSRA.

Thursday Night: VFR. Slight chance SHRA.

Friday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Tuesday... High Confidence.

Winds return to SW this morning. Local sea breezes along the 
east coast of MA. Relatively light seas across the waters 
through tonight. Could see some breezy winds near 20kts later 
this evening into Tuesday morning.

Outlook /Tuesday Night through Saturday/...

Tuesday Night through Wednesday Night: Winds less than 25 kt. 

Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers, slight chance of thunderstorms. 

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

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

&&

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

&&

$$

DISCUSSION...McMinn
AVIATION...Belk/BW
MARINE...McMinn