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 270707
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
307 AM EDT Mon Apr 27 2026

.WHAT HAS CHANGED...
Added small craft advisories for the northern waters Tuesday, while 
extending the existing small craft advisories through Tuesday
night.

&&

.KEY MESSAGES...

- Sunny and dry weather early this week. Above normal 
  temperatures for western/interior New England, but remaining 
  quite a bit cooler near the coast with seabreezes.

- Unsettled weather around Wednesday night and Thursday with a 
  welcomed soaking rain looking likely. 

- Remains unsettled Friday into the weekend with partly to
  mostly cloudy weather, cooler than normal temperatures and
  pop-up showers.

&&

.DISCUSSION...
KEY MESSAGE 1...Sunny and dry weather early this week. Above normal 
temperatures for western/interior New England, but remaining quite a 
bit cooler near the coast with seabreezes.

High pressure ridging in from coastal ME/NH is leading to clear 
skies, light to calm winds and a cool evening for most of Southern 
New England, and will remain in place the next couple days. Some 
residual cloud cover from distant coastal low will be gradually 
peeling off toward the southeast through the morning hours. 

This sets the stage for a couple of stellar couple days for us today 
and tomorrow to open up the workweek. Both days are generally 
similar - with full sun, deep blue skies with onshore flow and 
seabreezes for the east coast (and potentially the south coast too), 
to go along with good radiational cooling both nights. Away from the 
coast highs should reach into the 60s, with some lower 70s in the CT 
Valley, but near the coasts, highs will be kept in the lower to mid 
50s. PBL flow is next to nil with strong confidence in seabreeze 
devleopment, and it may penetrate quite a ways inland and bring some 
modest cooling this afternoon to I-495. Really nice couple days for 
outdoor activities. Lows each night in the mid 30s to low 40s.

The one potential fly in the ointment comes either late Tuesday or 
Tuesday night. Moisture from the offshore low looks to rotate back 
westward, with guidance varying on when that might occur, which 
could bring low clouds and possible drizzle to east coastal MA when 
it does set in. The timing will probably be tough to pin down over 
the next couple days but a best estimate looks to be sometime 
Tuesday night. Really not a significant impact though, aside from 
aviation. 

KEY MESSAGE 2...Unsettled weather around Wednesday night and 
Thursday with a welcomed soaking rain looking likely. 

The more active period of weather takes shape late Wednesday 
night and especially into Thursday. Overcast skies but mainly 
dry weather holds on for Wed, but by later Wednesday night into 
Thursday, a frontal occlusion with possible secondary low 
pressure development along it sweeps NNE through Southern New 
England. Pretty robust dynamics acting on a 1" PWAT airmass 
should bring a welcomed soaking rain. Some of the details are 
still uncertain this far out, including if and how strong might 
a secondary low pressure developing on the front might be. That 
would affect rain amounts and also enhanced ESE winds. Did look 
briefly at coastal flooding as astro tides start to come up 
Thursday too, but it would take about a 2 ft surge to get most 
areas to minor coastal flooding for the evening high tides and 
an early look suggests values around 1-1.3 ft, thus likely falling
short. Still, a good soaking rain with moderate to high probs 
of 24 hour rain of at least a half inch, and lower to moderate 
probs of 24 hour rains of at least an inch. 

KEY MESSAGE 3...Remains unsettled Friday into the weekend with 
partly to mostly cloudy weather, cooler than normal temperatures and 
pop-up showers.

Beyond Thursday...weather pattern remains unsettled with 
cyclonic flow aloft governing the area, bringing a return to 
cooler than normal temperatures and at least some partial 
cloudiness to open the first couple days of May. The question is
if we can generate any instability showers for Friday into the 
weekend underneath the trough. Earlier 12z guidance was hinting 
at this more bullishly, but the recent 00z guidance has backed
off and shunts most of the moisture off towards northern New 
England. If showers were to develop, they wouldn't necessarily 
be washouts but could produce some graupel given the 
anomalously cold airmass for early May (850 mb temps -1 to -4C).
Highs in the mid to upper 50s with a modest WNW wind. 

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...

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

06z TAF Update: 

Through 12z Monday: High confidence. 

Mainly VFR; a small chance for patchy mist/fog in the typically
favored western river valleys toward daybreak. Light to calm 
winds for most, otherwise NE winds 5-10 kt near the east coast.

Today and Tuesday: High confidence. 

VFR. NE winds around 10-15 kt with gusts to 25 kt Cape and
Islands for both days; otherwise NE to E winds 5-10 kt, 
lightest in the interior and on the higher end of that range for
eastern MA.

Tuesday Night: High confidence overall, but moderate along the
eastern coast.

VFR for most. Potential for coastal MVFR-IFR stratus as moisture
wraps back in from the ocean waters, but its timing is 
uncertain. Light N/NE winds. 

KBOS Terminal...High confidence in TAF. NE to E winds around
5-10 kt generally prevail today. There might be a possible
period of SE/SSE winds around 23z Monday-02z Tuesday before
winds return to light NE tonight.

KBDL Terminal...High confidence in TAF.

Outlook /Tuesday through Friday/...

Tuesday: VFR. Breezy. 

Tuesday Night through Wednesday: VFR. Slight chance SHRA.

Wednesday Night: Mainly VFR, with local IFR possible. Chance
SHRA.

Thursday: MVFR/IFR conditions possible. Breezy. SHRA, slight
chance TSRA.

Thursday Night: Mainly VFR, with local MVFR possible. Windy
with gusts up to 30 kt. Chance SHRA.

Friday: Mainly VFR, with local MVFR possible. Windy with local
gusts up to 30 kt. Slight chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Northeast winds will be strongest today over the southeast
waters adjacent to Cape Cod, with gusts in the 25 kt range and
seas building to around 4-6 ft. Otherwise, northeast winds and 
seas should remain below small craft advisory levels today. 

NE to N winds around 15-20 kt tonight into Tuesday, highest
eastern/southeast waters. The main issue is that seas from a
distant coastal low near the Maritimes will be building on most
of the eastern and southern outer waters; this has prompted
extending the existing ocean waters SCAs through Tuesday night
while adding the northern outer waters. Seas building to around
6-9 ft by Tuesday night.

Outlook /Tuesday through Friday/...

Tuesday: Winds less than 25 kt. Areas of rough seas. 

Tuesday Night through Wednesday: Winds less than 25 kt. Areas
of rough seas. Slight chance of rain showers. 

Wednesday Night: Winds less than 25 kt. Local rough seas.
Chance of rain showers. 

Thursday: Winds less than 25 kt. Local rough seas. Rain
showers, slight chance of thunderstorms. 

Thursday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers. 

Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft. Slight chance of rain showers. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 8 AM this morning to 8 PM EDT this 
     evening for ANZ232.
     Small Craft Advisory from 2 AM Tuesday to 2 AM EDT Wednesday 
     for ANZ250.
     Small Craft Advisory from 8 AM this morning to 2 AM EDT 
     Wednesday for ANZ254>256.

&&

$$

DISCUSSION...Loconto
AVIATION...Loconto
MARINE...Loconto