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

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

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 121124
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
724 AM EDT Fri Jun 12 2026

.WHAT HAS CHANGED...
The slight risk (level 2 of 5) of severe weather today remains in 
effect for far western CT and MA. The chance of severe weather also 
remains low, but not zero, for eastern MA/RI.

&&

.KEY MESSAGES...

- Heat Advisories advisories remain in effect for northern
  CT, central and northern RI, and most of MA through 8pm this
  evening.

- A few scattered strong to severe thunderstorms are
  possible this afternoon and evening. 

- Above normal temperatures continue into early next week, but humidity
  will be on the decrease. The weekend looks mostly dry with 
  the next round of showers and thunderstorms Sunday night, some
  of which could be strong.

- Cooldown to more seasonable temperatures with drier weather 
  for early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Heat Advisories advisories remain in effect for
northern CT and much of interior MA from noon today to 8pm 
Friday.

The worst of the heat and humidity peaks today away from the 
coastline. Temperatures soar into the mid 90s inland (low to mid
80s across the eastern coastal communities with onshore flow). 
Dewpoints near 70 combined with the high heat and sunny skies 
will lead to "feel like" temperatures in the upper 90s to near 
100 (in the CT River Valley) this afternoon. Therefore, the Heat
Advisory remains in effect through this evening.

KEY MESSAGE 2...A few scattered strong to severe thunderstorms 
are possible this afternoon and evening.

The lingering hot and humid airmass clashing with a mid-level 
shortwave over southern Quebec and northern New England will 
provide enough lift to produce a few rounds of thunderstorms 
today. Earliest storms are likely to pop over eastern MA and RI 
along a stagnating sea breeze boundary this afternoon. A 
secondary round of thunderstorms, with the highest change of 
becoming severe, likely fires later in the evening over western 
MA and CT as a cold front approaches. Some uncertainty remains 
this morning in exactly how far east storms could push, as the 
latest suite of guidance is indicating CAPE values upwards of 
1200 J/kg quickly decaying around sunset. Model soundings 
continue to show DCAPE values near or above 1000 as well as 
PWATs 1.5-2.0", which lean confidence to the greatest risks with
any storms that do form to be heavy to torrential rainfall as 
well as severe wind gusts. 

KEY MESSAGE 3...Above normal temperatures continue into early 
next week, but humidity will be on the decrease. The weekend 
looks mostly dry with the next round of showers and 
thunderstorms Sunday night, some of which could be strong.

While temperatures remain well into the 80s through the 
weekend, dewpoints will drop to the mid to upper 50s Saturday, 
leading to some much needed relief from the sticky airmass we've
been seeing. A ridging pattern will also move into New England,
bringing generally dry conditions through the weekend.

Expecting the next round of potential showers and thunderstorms
Sunday night into Monday with another approaching cold front. 
Despite the return of southwesterly flow, and thus higher 
dewpoints, guidance is indicating instability remains on the 
lower side, potentially limiting the chances for storms to 
become severe in nature. Regardless, quite confident in at least
showers with some embedded rumbles of thunder.

KEY MESSAGE 4...Early next week could feature a brief cooldown 
to more seasonable temperatures.

Once the cold front from Sunday pushed offshore, 850mb 
temperatures cool to near single digits (C) compared to the 
upper teens we've been seeing. This will help moderate 
temperatures down to the upper 70s or low 80s with lower 
humidity Monday and Tuesday.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

12Z TAF Update:

Friday: Moderate confidence.

VFR. Light onshore winds developing, with light W winds away 
from the coastal TAFs. A few rounds of TSRA could develop, first
in the 18-00Z time period over eastern MA and RI terminals 
along the seabreeze boundary, but confidence in coverage and
placement is low. Then again a broken line of storms is 
possible in the 23z-06z period, diminishing as it moves east. 

Friday night...High confidence.

SHRA/TSRA exiting by 06z. VFR except near the Cape/Islands 
where MVFR visbys under BR may creep in off the waters. NW winds
5-10 kts.

Saturday....High confidence.

VFR. Generally northwesterly winds around 10 kts.

KBOS Terminal...Moderate confidence in TAF. VFR. Could see a 
few TS develop 16-23z Fri along the seabreeze boundary, but 
confidence remains to low to include in TAF.

KBDL Terminal...Moderate Confidence in TAF. VFR. Light W winds 
turn southerly with a round of late-day TS possible.

Outlook /Saturday Night through Tuesday/...

Saturday Night: VFR. 

Sunday: VFR. Breezy. 

Sunday Night: Mainly VFR, with local MVFR possible. Breezy.
Chance SHRA, slight chance TSRA.

Monday: VFR. Breezy. 

Monday Night through Tuesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Saturday Morning...High confidence.

Seas generally 1-3 ft, except 3-4 ft across the far outer water
through Saturday morning. Isolated to scattered showers 
possible again Friday night. Otherwise, winds remain below SCA 
levels.

Outlook /Saturday Night through Tuesday/...

Saturday Night through Sunday: Winds less than 25 kt. 

Sunday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Rain showers, slight chance of thunderstorms. 

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

Monday Night: Winds less than 25 kt. 

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ002>004.
MA...Heat Advisory until 8 PM EDT this evening for MAZ002>006-
     008>014-017-018-026.
     Air Quality Alert from 11 AM this morning to 11 PM EDT this 
     evening for MAZ017>024.
RI...Heat Advisory until 8 PM EDT this evening for RIZ001>004.
     Air Quality Alert from 11 AM this morning to 11 PM EDT this 
     evening for RIZ001>008.
MARINE...None.

&&

$$

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