235
FXUS61 KBOX 051120
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
620 AM EST Fri Dec 5 2025

.SYNOPSIS...
The winds from early this morning will quickly diminish today,
but it remains unseasonably cold. Scattered snow or rain showers
into Saturday with a low pressure system passing well to our
south. Another arctic cold front crosses the region overnight
Sunday with a chance for a few snow/rain showers. Well below
normal temperatures Monday before slowly moderating
Tuesday/Wednesday. More unsettled overall next week with a few
disturbances moving through bringing periodic chances for
rain/snow showers late Tue-Wed and Wed-Thu.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Message:

* Chilly and dry conditions across southern New England

High pressure continues to exert its influence over the region. Cold
and dry conditions prevail over southern New England today with
weakening northwesterly winds. The colder airmass remains over the
region with 925 mb temperatures only improving to around -10C for
the early afternoon hours, so even with sunny skies, highs will only
reach the 20s for most and sit just around freezing for Cape Cod and
the Islands. Weak southerly flow kicks up heading into the evening
as high pressure starts to shift more to the east

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Key Messages:

* Cold overnight, but more clouds filtering in with weak southerly
  flow

* Some scattered rain/snow showers possible Saturday, though the
  chance remains low (30% and less)

High pressure continues moving offshore overnight Friday, allowing
for weak southerly flow to continue. 925 mb temperatures improve to
around -5C to -2C by 7 AM Saturday and clouds will fill in a bit
more through the night as a result. Temperatures should improve as
the night goes on with the lowest temperatures most likely before
midnight. Lows will range between the teens and 20s.

As noted in the previous forecast, we find ourselves between a
trough moving across northern New England and a surface low passing
well to our south. Latest CAMs guidance along with the HREF are
indicating that some showers are possible for Saturday, particularly
for eastern MA, Cape Cod, and RI. High temperatures in the mid 30s
for the interior and into the mid 40s towards the coastal areas are
expected, which would trend precip to be more liquid than snowy.
However, some light flurries cannot be completely ruled out in the
mid-morning hours across central MA and parts of eastern MA. These
showers are not expected to be impactful unless lingering moisture
on the roads refreezes Saturday night.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Key Messages:

* More arctic air arrives Sunday night into the early part of next
  week.

* Snow or rain/snow showers possible Sun night-early Mon.

* Periodic chances for precipitation next week (Tue-Wed & Wed-Thu),
  exact timing, amounts lower confidence.

 Details...

There is a general consensus among ensemble guidance for a shortwave
trough to move across the region later Sunday into Monday
accompanied by another arctic frontal passage. Majority of guidance
shows a weaker shortwave with limited moisture which would point to
the more likely scenario of some flurries/snow showers with the
front overnight Sunday into early Monday morning, perhaps .
ECMWF/Canadian ens show high probabilities for less than 1.0" snow,
if any accumulates, so very light/scattered event. However, the
deterministic GFS and its ensemble suite have been hinting at an
overall wetter solution with this system. It displays a more
amplified wave along with a surface low that tracks just offshore.
The stronger forcing and moisture have resulted in more/widespread
precipitation with probabilities 40-70% for an inch of snow or
greater north of I-90, with probabilities tailing off toward 3
inches. Depending on how the low tracks, the Cape start as rain
showers before changing over to snow. Given is more of an "outlier",
it is just something to keep an eye on for now.

Below normal temperatures and breezy NW winds on Monday with highs
in the 20s to low 30s and wind chills in the teens. Mainly dry
conditions with the exception of a few ocean-effect showers for the
Cape/Islands possible. Below normal temperatures continue Tuesday,
although slightly moderated from Monday with highs in the mid-upper
20s for the higher elevations and 30s elsewhere.

Confidence in the pattern decreases toward mid-week, but there are
indications of a few weak disturbances moving through later Tuesday
into Wednesday and another one Wednesday-Thursday bringing potential
for precipitation. Details are still uncertain (timing, amounts,
precip type), but will become more clear as we gain a better
consensus on the upper level pattern and the timing of each
wave.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

12Z TAF Update:

No significant changes from the previous update.

Friday...High Confidence.

VFR for most. Ocean effect VFR/MVFR ceilings at HYA/ACK and
Outer Cape through about 20Z. Winds start WNW at 5-10 kt,
shifting to SW/S toward the afternoon. A layer of VFR/MVFR
bases shift toward the immediate south coast, Cape and Islands
around 00Z.

Friday Night...Moderate to High Confidence.

VFR initially, though a layer of VFR/MVFR cloud decks advance
northward from the southern waters. Low prob of SHSN/flurry or a
very spotty FZDZ possible around PVD. Light south winds.

Saturday...Moderate Confidence.

Low end VFR to MVFR ceilings. Light SW winds. Low chance for a
light rain/snow shower.

KBOS Terminal...High confidence through 15z Saturday, then
Moderate confidence.

Low chance exists for -RASN after 15z Saturday. Ptype is still
not fully certain. Latest CAMs indicate a chance for precip in
the late morning/early afternoon. Included as a PROB30 for the
time being.

KBDL Terminal...High confidence in TAF.

Outlook /Saturday Night through Tuesday/...

Saturday Night through Sunday: VFR.

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

Monday: VFR. Windy with local gusts up to 30 kt. Slight chance
SN.

Monday Night: VFR. Breezy.

Tuesday: VFR. Breezy. Slight chance SN.

&&

.MARINE...
Forecaster Confidence Levels...

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

* Gale Warnings downgraded to Small Crafts until 4 AM today

NW gusts will subside early this morning. Gusts and seas should
subside to below SCA levels into later Fri AM.

Dry weather should generally dominate, but there may be some
ocean effect clouds with possible flurries or ocean effect snow
showers that could briefly/locally reduce visibility through
midday today. Winds turn southerly around 10-15 kt tonight.

Seas remain calm Sat with winds around 10-15 kts through the
afternoon.

Outlook /Saturday Night through Tuesday/...

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

Sunday: Winds less than 25 kt.

Sunday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain, chance of snow.

Monday: Strong winds with gusts up to 30 kt. Seas up to 5 ft.
Chance of rain, slight chance of snow.

Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Local rough seas.

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of seas approaching 5 ft. Slight chance of
rain.

&&

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

&&

$$

SYNOPSIS...Hrencecin/Mensch
NEAR TERM...Hrencecin
SHORT TERM...Hrencecin
LONG TERM...Mensch
AVIATION...Hrencecin/Mensch
MARINE...Hrencecin/Mensch