Old Res Weather

Lexington, Massachusetts, USA

35°F

2/16/2025 7:17pm

Lexington Conditions: Overcast
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 011823
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
223 PM EDT Fri May 1 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- Passing light rain showers early Saturday morning from 
  interior Southern New England to the coastal plain, but better
  chances for steady light rain for southeast New England later
  Saturday afternoon through Sunday morning.

- Sunny and dry with above normal temperatures Monday and 
  Tuesday, with southwesterly breezes.

- Turning more unsettled mid to late next week with showers and
  possible thunderstorms.

&&

.DISCUSSION...
KEY MESSAGE 1...Passing light rain showers early Saturday
morning from interior Southern New England to the coastal plain,
but better chances for steady light rain for southeast New 
England later Saturday afternoon through Sunday morning.

Although dry weather prevails today and most of tonight,
monitoring a couple of periods of showers for Saturday into part
of Sunday. 

The first of these shower chances is with a lead 500 mb 
shortwave disturbance now over eastern OH, which is bringing
clouds and rain showers to western NY and northwest PA as of
Friday afternoon. Expect increasing clouds and passing light
rain showers to move into western MA and CT closer to the pre-
dawn hours Saturday, then steadily moving eastward into central
and eastern MA around mid to late Saturday morning. These are
really light passing showers, perhaps enough to wet pavement but
nothing more. QPF amts with this round of showers should be less
than a tenth of an inch. 

A more robust system coming out of the Gulf Coast states tonight
into early on Saturday then deepens to a sub-990 mb cyclone as 
it takes a track NE to a path east of the 40N/70W benchmark for
late Saturday/Saturday night and continuing northward into 
Sunday. The western extent of this system's rain shield is still
in some question, with the 12z GFS in particular being quite a
bit drier than most other guidance. Advancing drier air into 
interior Southern New England on NW winds should mitigate rain 
chances there, but the western edge of steadier rains looks to 
be into the MA/RI coastal plain to around I-495, where rain 
totals are up to a quarter to third of an inch. Strongest 
chances for steadier light rain and mist would be across the 
South Coast, Cape Cod and the Islands starting later Saturday 
afternoon, with wrap- around rain continuing into early Sunday 
before pulling away Sunday afternoon. Rain totals for these
southeastern areas Saturday and Sunday around a half to three- 
quarters of an inch. 

All told, not really a great weekend if your plans bring you to
Cape Cod or eastern MA and RI, but conditions in CT and western
MA should be quite a bit better. Highs mainly in the 50s on 
Saturday with clouds and periods of showers, cooler lower 50s in
southeast New England; on Sunday, highs have a decent shot at 
reaching the low 60s in western interior Southern New England, 
but are in the mid 50s near the eastern coast as it will take 
quite a bit longer before we can see peeks of sun develop. 

KEY MESSAGE 2...Sunny and dry with above normal temperatures 
Monday and Tuesday, with southwesterly breezes.

We get into a warming trend toward above normal temperatures 
for early next week with SWly breezes for Monday and Tuesday. 
Highs in the 60s to lower 70s on Monday, but diurnal mixing of 
lower dewpoints (RHs down to around 30 percent) to go along with
breezy southwest winds could warrant fire weather concerns on 
Monday. Temperatures are even warmer with most areas away from 
the southeast coast well into the 70s, except SW winds look to 
be a little lighter and relative humidities aren't quite as low.
Will assess how much rain actually falls and then consider fire
weather partner input before weighing a decision on fire weather
headlines, but they could be possible on Monday and possibly
Tuesday.

KEY MESSAGE 3...Turning more unsettled mid to late next week
with showers and possible thunderstorms.

500 mb pattern amplifies by midweek, with a pronounced upper
trough over the nation's midsection and an amplifying ridge
associated with above normal temperatures over the eastern and
southeast US into the western Atlantic. A slow-moving frontal
boundary will be progressing eastward with low pressure
developing along it at some point late in the week - guidance
varies on when this happens but loose consensus around Thursday.
Pretty robust dynamics and decent moisture plume could favor
several opportunities for showers and even a few thunderstorms
around late in the week. We do need the rain so this should be
more beneficial than necessarily hazardous, but either way,
expect temperatures to remain slightly above normal but with
chances for rain on the increase. 

&&

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

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

18z TAF Update: 

Through Tonight: High confidence.

VFR generally governs, though risk for -SHRA and low-end VFR/MVFR
ceilings at BDL and ORH after 06z Sat. WNW winds around 10 kt, 
with gusts 18-22 kt for eastern New England through at least 
22z Fri. Winds then slacken to light west, though they could be
light enough to allow for winds to turn onshore for a while 
(around 23z-04z) at BOS, before flipping to south 5-10 kt in 
all areas tonight and overnight. 

Saturday: Moderate confidence. 

OVC low-end VFR/MVFR ceilings with passing -SHRA over interior
CT/western MA advancing east through 17z to BOS. Although SHRA
comes to an end for interior Southern New England airports by
afternoon with VFR ceilings and NW winds around 5-10 kt, better
chance for 4-6 SM -RA and MVFR ceilings comes in after 20z for 
BOS, PVD and the Cape airports as coastal low pressure begins to
approach. S winds become SE/ESE Sat afternoon for eastern 
airports around 5-10 kt.

Saturday Night: Moderate confidence. 

VFR from ORH westward, but MVFR ceilings and steadier -RA
continues for PVD, BOS, and the Cape airports. Winds come 
around to NW around 10 kt Sat night.

KBOS Terminal...High confidence in TAF. Winds to go light late
in the day, around 22-04z, which could allow for a period of
light onshore winds to develop before becoming S around 5 kt.

KBDL Terminal...High confidence in TAF.

Outlook /Saturday Night through Wednesday/...

Sunday: Mainly VFR, with local MVFR possible. Breezy. Chance
RA.

Sunday Night through Tuesday: VFR. Breezy. 

Tuesday Night: VFR. Breezy. Slight chance SHRA.

Wednesday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Overall high confidence.

Winds and seas should remain below small craft advisory levels
through Saturday night. NW winds around 15-20 kt slacken and
become southerly tonight and into Saturday around 10-15 kt, with
seas 4 ft or less all waters. Mainly dry weather, though rain
begins to increase on the southern waters later Saturday and
continues into Saturday night.

Winds and seas then become closer to small craft advisory
levels Sunday as winds turn NW with gusts 20-25 kt and seas 
building to 4-6 ft on the outer waters. Possible need for SCAs 
on the eastern outer waters for Sunday. Rain could also locally
reduce visibility.

Outlook /Saturday Night through Wednesday/...

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Local rough seas. Rain. 

Sunday Night: Winds less than 25 kt. Areas of rough seas. 

Monday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft. 

Monday Night: Winds less than 25 kt. Local rough seas. 

Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. 

Tuesday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. 

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

&&

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

&&

$$

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