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 100603
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
203 AM EDT Wed Jun 10 2026

.WHAT HAS CHANGED...
Showers and storms may return Wednesday evening as a warm front 
approaches the region. No major changes otherwise.

&&

.KEY MESSAGES...

- Dry through the rest of today and tonight before the risk for
  showers and thunderstorms returns Wednesday afternoon/evening.

- Diurnal showers and thunderstorms possible Wednesday through
  Friday. Above normal temperatures peaking Thursday into Friday.

- Warm conditions with lower humidity throughout this weekend. 
  Uncertainty remains high regarding potential rain showers for 
  Saturday, and again early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Dry through the rest of today and tonight before
the risk for showers and thunderstorms returns Wednesday 
afternoon/evening.

High pressure south of Long Island continues moving off to the
south and east as the ridge aloft starts receding from the 
northeast US. Some shortwave disturbances will then start to 
make their way across the region as its influence wanes, which 
will aid in the return of some showers and storms. Lows tonight 
will generally be in the upper 50s and low 60s as light SW winds 
continue for most; winds to 15 kt will be possible through 
tonight across the Cape and Islands.

A warm front will push through southern New England Wednesday 
evening/night and showers and thunderstorms will likely
accompany it. With regards to severity, not seeing much that 
would scream a severe weather threat with these possible storms.
CSU ML guidance has about a 5-15 percent chance for severe 
winds in western MA and CT, along with part of central MA for 
Wednesday. Winds also shift more southerly going into Wednesday 
afternoon/evening, helping bring in more moisture from the 
south. PWATs may approach 2.0", and NAEFS guidance indicates 
that values Wednesday into Thursday morning may be around 2-3 
standard deviations above normal. Details regarding the coverage
of these showers and storms still need to be ironed out, but 
the latest guidance is favoring the heavier rainfall remaining 
to our north and south. With the moist airmass overhead, some 
spots with locally heavier rainfall can't be ruled out, but much
can still change between now and when this front comes through.
Rainfall amounts at this time may only reach around 0.10-0.20".
Hot and humid conditions will be left in the wake of this warm 
frontal passage.

KEY MESSAGE 2...Diurnal showers and thunderstorms possible
Wednesday through Friday. Above normal temperatures peaking 
Thursday into Friday.

High pressure towards the southeast USA will push heat and
humidity into southern New England later this week. Will 
likely need to consider heat headlines with later forecasts. 
Uncertainty remains for how quickly and how far west a backdoor 
cold front can make it Friday. This would have implications for 
heat headlines across eastern MA as well as RI. Should this 
front be delayed from its current timing, then more of southern 
New England would be at risk for headlines using the lower 2-day
threshold.

Portions of the CT River Valley in MA and CT could see heat
index values around 100F, while more of our region should be 
well into the 90s both Thursday and Friday. Coastal areas of MA 
and RI are expected to be cooler Friday, but the timing still 
needs to be ironed out.

The increased heat and humidity will also set the stage for
possible showers and thunderstorms later this week. There is 
not much concern for the threat of widespread severe
thunderstorms at this time due to the lack of wind shear and
weak forcing mechanisms. The western half of southern New
England would have the higher risk, which is not unusual for
this time of year.

KEY MESSAGE 3...Warm conditions with lower humidity throughout
this weekend. Uncertainty remains high regarding potential 
rain showers for Saturday, and again early next week.

Anticipating the passage of a couple fronts Saturday and Sunday.
The main impact will be lower humidity, with Sunday anticipated 
the drier of the two. Lingering showers possible Saturday, but 
plenty of dry hours too. Some guidance members indicated a weak 
low pressure passing by towards the south coast of New England 
sometime Monday into Tuesday. Kept a mention of showers in the 
forecast, but confidence in these details is low.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

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

Through Tonight...High confidence.

VFR conditions continue through much of today. Some MVFR to 
localized IFR conditions may overspread parts of the region from
southwest to northeast by early this evening along with a few 
showers. Showers become more likely tonight, but coverage is 
still relatively uncertain, with western teminals most likely to
see showers and possibly a rumble of thunder.

Lingering gusts across the Cape/Island tonight into the early 
morning hours, but relatively calm eslewhere. Otheriwse, gusts 
to around 20 kt may make a return by the mid/late morning hours.
SW winds will persist through tonight and into Wednesday before
shifting more S Wednesday night in the wake of a passing warm 
front.

Thursday Morning...Moderate confidence.

Generally MVFR/IFR conditions. Some areas could be on the cusp 
of LIFR conditions as any lingering showers push offshore. SW 
winds continue through the morning hours, generally around 10 
kts once showers move out.

KBOS Terminal...High confidence in trends. Moderate confidence 
is timing.

Some uncertainty remains if -SHRA will make it to the terminal.
Included a PROB30 at this time. 

KBDL Terminal...High confidence in trends. Moderate confidence 
is timing.

Some uncertainty remains in the exact timing of -SHRA, as well 
as if -TSRA is possible later in the overnight hours.

Outlook /Thursday Night through Sunday/...

Thursday Night: VFR. Slight chance SHRA.

Friday: Mainly VFR, with local MVFR possible. Chance SHRA,
chance TSRA.

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

Saturday: VFR. Slight chance SHRA.

Saturday Night through Sunday: VFR. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Thursday Morning...High confidence.

Winds shift more SW then SSW Wednesday afternoon, sustained at 
around 15-20 kt with gusts remaining just below Small Craft 
criteria. Seas generally 2-4 ft through Wednesday night, though 
the southern outer waters may start to creep to 5 ft heading 
into Thursday morning.

Outlook /Thursday Night through Sunday/...

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

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

Friday Night through Saturday: Winds less than 25 kt. Slight
chance of rain showers. 

Saturday Night through Sunday: Winds less than 25 kt. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from noon Thursday to 8 PM EDT Friday for 
     CTZ002>004.
MA...Heat Advisory from noon Thursday to 8 PM EDT Friday for MAZ002-
     003-008>011.
RI...None.
MARINE...None.

&&

$$

DISCUSSION...Belk/Hrencecin
AVIATION...McMinn
MARINE...McMinn