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 051722
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
122 PM EDT Wed Aug 5 2026

.WHAT HAS CHANGED...
Confidence continues to increase in southern New England seeing
a prolonged period of high heat and humidity through the second
half of the week and into the weekend.

&&

.KEY MESSAGES...

- Generally dry today with increasing humidity. Low risk for
  early morning showers across the Islands.

- Summer heat and humidity returns Thursday through the weekend
  with chances for diurnal scattered thunderstorms possible each
  day.

&&

.DISCUSSION...
KEY MESSAGE 1...Generally dry today with increasing humidity. 
Low risk for early morning showers across the Islands.

A weak high pressure over western CT has brought mostly clear 
skies and calm winds to southern New England, leading to a 
little bit of river valley fog and dropping temperatures to 
around 60 across the usual radiator sites. A weak low pressure 
system has spun up over our southern waters tonight, leading to 
some scattered showers forming over the far southeastern waters,
and there remains a low chance for those showers to push inland
towards Nantucket through the early morning hours.

The high pressure should linger near NYC today, leading to 
generally dry conditions for most of southern New England. The 
low will slowly meander further east and offshore today as well.
Once the low moves out to sea, winds will become predominately 
southerly, pushing warm, moist air onshore and dewpoints will 
begin to slowly tick up throughout today... likely approaching 
70 by this evening. Otherwise, temperatures today remain in the 
mid to upper 80s with plenty of sunshine.

KEY MESSAGE 2...Summer heat and humidity returns Thursday 
through the weekend with chances for diurnal scattered 
thunderstorms possible each day.

A Bermuda high will begin to build in across the western 
Atlantic Ocean and as southerly flow continues through the 
night, dew points begin to surge into the mid to upper 70s by 
Thursday. 925 mb temps surge to near +22C each afternoon this 
week, leading to high temps near 90 Thursday through Saturday. 
Combined with near oppressive dew points of 72-76, "feels like" 
temperatures will climb to the upper 90s, possibly near 100 at 
times. Heat headlines are being considered through the second 
half of the week and possibly into the weekend; however, some 
uncertainty remains in exactly how hot southern New England 
could get with daily threats for diurnal thunderstorms.

Regarding the thunderstorm potential later in the week... a few
weak, upper level disturbances passing through New England 
combining with the high heat/humidity and just enough 
instability will likely be enough to pop a few diurnal 
showers/thunderstorms each day Thursday through the weekend, 
with greatest chances across the interior on Thursday. Any 
thunderstorms that do pop have the potential to produce frequent
lightning, gusty winds, and torrential downpours as PWATs will 
likely be around 2.0". Given the amount of rain southern New 
England has seen over the last week or so, any heavy downpours 
could lead to localized flooding.

&&

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

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

18z TAF Update:

Tonight...High Confidence.

Generally VFR. Increasing moisture tonight should result in 
MVFR/IFR CIGS, especially across the southern coastal areas and
the Cape. May also see a few -SHRA develop prior to 12z 
Thursday across CT. Most MVFR/IFR CIGS mix out after 12-14z
Thurs. 

Thursday...High Confidence. 

Mix of VFR with MVFR cigs for western terminals early, becoming
VFR. Chance for -SHRA and -TSRA across western terminals well 
after 18z. SW winds 5-10 kts.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Thursday Night through Monday/...

Thursday Night: VFR. 

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

Friday Night: VFR. Chance SHRA, slight chance TSRA.

Saturday: VFR. Breezy. Chance SHRA, chance TSRA.

Saturday Night: VFR. Breezy. Slight chance SHRA, slight chance
TSRA.

Sunday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Thursday... High Confidence.

Conditions generally below SCA levels through Thursday as a 
broad high pressure system sets up over the western Atlantic. A 
few periods of gusty SW winds near 20 kts are possible tonight 
across the northeastern waters and Thursday across the southern 
waters. 

Outlook /Thursday Night through Monday/...

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

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

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

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

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

&&

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

&&

$$

DISCUSSION...McMinn
AVIATION...McMinn/FT
MARINE...McMinn