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 231715
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
115 PM EDT Thu Apr 23 2026

.WHAT HAS CHANGED...

No significant changes.

&&

.KEY MESSAGES...

- Dry and seasonable weather prevails through the weekend,
  although some light rain is possible in western New England 
  Saturday.

- Pattern turns more unsettled next week with several chances
  for beneficial rainfall.

&&

.DISCUSSION...

KEY MESSAGE 1...Dry and seasonable weather prevails through the weekend,
although some light rain is possible in western New England
Saturday.

Winds diminish tonight as high pressure builds into New England. 
Even though low level moisture will recover as deep mixing subsides 
this evening, it's still a dry airmass in place and that means we'll 
see radiational cooling outside of urban areas and away from the 
immediate coast, especially in RI and eastern MA. 

Farther to the west, strong upper jet may provide enough convergence 
aloft to produce clouds and perhaps a few sprinkles across CT later 
tonight, though most of the forcing appears to be farther to the SW. 
Several of the high-res models show narrow bands of reflectivity but 
note it's too dry in lower levels to support precipitation. That 
will also keep temperatures from bottoming out too low there.

Blocky pattern continues into weekend as closed low remains over 
Maritimes and upper ridge stays in place across Great Lakes. Between 
the two, confluent NW flow will dominate which should keep southern 
New England dry overall as surface high pressure remains in control. 
However, upper low may shift just far enough to east to allow weak 
short wave and surface low to pass just south of New England, 
producing a NW-SE oriented band of clouds and showers that could 
reach western MA and much of CT, while areas farther east remain 
dry. Thermal profiles also support some wet snow in the hills, 
especially Saturday night, but probably no more than a coating on 
the grass. 

Ensemble probabilities show about a 50/50 chance for measurable 
rainfall (0.01" or more) along a line from Stockbridge, MA to 
Hartford and New London, CT with higher chances to the west (60-70%) 
and a sharp cutoff (<30%) to the east. Since these are based on 
coarser global models, in reality there will probably be a sharp 
cutoff as to how far into MA/CT any showers can get; it's certainly 
possible that we end up more with cloudy skies in western New 
England with little or no rain at all. We're not quite into window 
for high-res models but 12km NAM does show a similar pattern.


KEY MESSAGE 2...Pattern turns more unsettled next week with several 
chances for beneficial rainfall.

Closed upper low moves farther out to sea over North Atlantic early 
next week and from there we see fairly significant differences among 
longer range guidance as to how the pattern will unfold, although 
each guidance cluster shows trough moving through eastern U.S. and 
either ridging to its north or back across Great Lakes.

No matter which solution ends up being more correct, this setup
favors a series of low pressure systems heading across northern
tier of states potentially bringing showers in Tue-Wed 
timeframe and perhaps again Thu. This certainly doesn't look 
like a setup for excessive rainfall but one that should bring 
needed rainfall to region. Temperatures look to average near or 
just above late April normals which are in the upper 50s to mid 
60s.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...

Forecaster Confidence Levels...

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

18z TAF Update: High confidence.

VFR. NW winds gusting to 25-30kt inland will diminish toward sunset 
followed by lighter N winds Fri. Expect winds to turn NE along E MA 
coast Fri afternoon with sea breezes possible after 18z.

KBOS Terminal...High confidence in TAF. 

KBDL Terminal...High confidence in TAF. 

Outlook /Saturday through Tuesday/...

Saturday: VFR. 

Saturday Night through Monday Night: VFR. Slight chance SHRA.

Tuesday: Mainly VFR, with local MVFR possible. Chance SHRA.

&&

.MARINE...

Forecaster Confidence Levels...

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

High confidence through this weekend.

High pressure builds into region through tonight and remains in
place through early next week, keeping winds and seas below SCA.

Outlook /Saturday through Tuesday/...

Saturday: Winds less than 25 kt. 

Saturday Night through Monday: Winds less than 25 kt. Chance of
rain showers. 

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

&&

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

&&

$$

DISCUSSION...JWD
AVIATION...JWD
MARINE...JWD