841
FXUS61 KBOX 191729
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1229 PM EST Wed Nov 19 2025

.SYNOPSIS...
Aside from some rain later Friday into Saturday ahead of a cold
front, dry and seasonably cool weather will prevail through
early next week as high pressure dominates our weather.

&&

.NEAR TERM /THROUGH TONIGHT/...
Updated 1230 PM Wed

Key Messages:

* Clearing along South Coast, setting up a cold night.

Showers south of New England were moving farther out to sea as
low pressure and mid level shortwave head offshore. Satellite
shows clearing not far behind so expect south coastal locations
to clear out later this afternoon, leaving clear skies across
SNE tonight. Combination of dry airmass and light N winds will
result in good radiational cooling. NBM isn`t too far off from
colder MOS guidance but expect some of the typical cold spots to
drop into upper teens tonight. This includes parts of upper cape
Cod and KMVY (in the middle of the island in pine barrens).

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Updated 1230 PM Wed

Key Messages:

* Dry weather and below normal temperatures.

High pressure remains over SNE Thu before heading to the
Maritimes Thu night resulting in some high cloudiness due to
fairly zonal flow aloft and weak warm advection. Temperatures
Thu should average a few degrees higher than today followed by
another cold night Thu night.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Updated 200 AM Wed

Key Messages:

* No impactful weather expected Friday through early next week. A
  chance for showers late Friday into early Saturday, otherwise a
  mainly dry period of weather.

Deterministic models and ensemble members continue to have agreement
with a northern stream shortwave moving across northern New England
Friday evening. Thus, expect the daylight hours remains dry, with a
better chance for showers overnight into early Saturday. Where there
is disagreement is among how much moisture is available. GFS is the
most robust, with PWATs above 1.0" while ECMWF, NAM, and Canadian
favor less in the way of moisture. Generally less than 0.5" for the
areas away from the south coast of CT, RI, and MA. Do think the GFS
is more robust is due to a weak low pressure system development over
southern New England during this time frame. This scenario remains
an outlier. Nevertheless, this is a weakly forced environment and do
not expect any impacts. FWIW, DESI probabilities for 0.10" are best
south of I-90 between 30 to 50 percent. A southwest flow leads to a
warmer, albeit seasonable day, temperatures on Friday reach low-50s
for the coastal plain and upper-40s across the high terrain. A cold
front swings through on Saturday, 850mb temperatures at 12z are +5C
to +7C at 12z and by 00z temperatures drop -2C to 0C. Any lingering
moisture could result in a few flurries on Saturday. Highs are in
the 30s for the high terrain and 40s for the coastal plain.

Area of high pressure builds across the eastern seaboard Sunday into
early next week. The 500mb pattern is quasi-zonal, a weak shortwave
does pass through on Sunday, but given the dry atmosphere, think it
adds more clouds than anything to the forecast, otherwise a dry day.
Monday and Tuesday there is subtle mid-level ridging and continued
surface high pressure, dry conditions remain during this period. As
for temperatures highs are generally in the upper-40s to lower-50s
and nighttime lows in the 30s.

&&

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

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

18z TAF Update: High confidence.

Theme remains the same with VFR conditions through Thu night.
W/NW winds 10kt or less veer to N later this afternoon and
persist through Thu, although winds should veer more to NE along
coast.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Friday through Sunday/...

Friday through Friday Night: Mainly VFR, with local MVFR
possible. Slight chance RA.

Saturday through Sunday: VFR. Slight chance RA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Updated 1230 PM Wed

High confidence through the weekend. No headlines anticipated.

High pressure maintains light N/NE winds through Thu.
Approaching cold front late Fri into Sat should bring some rain,
before another high builds into region over weekend.

Outlook /Friday through Sunday/...

Thursday Night: Winds less than 25 kt.

Friday: Winds less than 25 kt. Slight chance of rain.

Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain.

Saturday: Winds less than 25 kt. Chance of rain.

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

&&

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

&&

$$

SYNOPSIS...JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...Dooley
AVIATION...JWD
MARINE...JWD