279
FXUS61 KBOX 081926
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
226 PM EST Mon Dec 8 2025

.SYNOPSIS...
Very cold overnight with an arctic airmass in place, followed by a
cold and dry Tuesday. Have improving temperatures for the middle
part of the week, but this comes with unsettled conditions beginning
with Tuesday night. Unsettled with a few systems moving through the
region, bringing periodic chances for rain and or snow showers into
Saturday. Trending cooler later in the week, then below normal
temperatures returning by the end of the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

* Turning very cold overnight, with areas dropping below zero in the
  far north/northwest areas of Massachusetts.

No significant weather concerns for the rest of today and tonight as
an area of high-pressure settles overhead; which originated near the
Arctic Circle. Periodic wind gusts this afternoon will diminish with
a light to calm wind overnight. Clear sky in conjunction with light
winds leads to radiational cooling. Temperatures at 500mb are -32C
to -30C, which is anomolously cold; 10th percentile of climatology
for today`s date per Chatham sounding climatology. Expecting frigid
temperatures, coldest across northern and western Massachusetts
where snow depth ranges between 4 and 8 inches, here the overnight
temperatures lower between low single digits to a few degrees below
zero. Elsewhere, temperatures are in the single digits and teens
near the coast.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
Key Messages:

* Dry conditions through the daylight hours of Tuesday, then a quick
  hitting system brings snow/rain showers overnight to the region.

* Minor snow accumulations are possible, but not expected to be
  widespread.

Quiet and dry weather throughout the daylight hours Tuesday, with
the most active period overnight into Wednesday morning. During the
daytime an area of high-pressure moves east of New England, clear
skies gives way to increasing cloud cover during the afternoon as
WAA bring elevated PWATs into the region. Overall, chilly day as
925mb temperatures are -8C to -6C and with a mixed boundary layer,
afternoon high temperatures are once again in the 20s to mid-30s at
the coast.

Tuesday night, mid-level warm front and 850mb frontogenesis, between
00z-06z, provides a brief hit of snow showers. The layer doesn`t
appear super saturated, thus not anticipating significant snowfall.
High-res models picked up on this, indicating brief round of snow
showers and coastal rain showers, from 7pm and 1am. Antecedent
temperatures may allow for minor accumulations on paved surfaces of
a few tenths of an inch. But, the higher end amounts of up to an
inch remains possible, though not expected to be widespread.

Any wet and untreated surfaces could become slick as the overnight
temperatures are below freezing between the  upper teens through the
20s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Key Messages:

* Periodic chances for precipitation through Sunday.

* Uncertainty in pattern details (timing, amounts, precip type),
  especially Wednesday onward.

Rather good overall agreement with the synoptic pattern amongst the
latest guidance suite members. Timing and amplitude differences
continue to grow into this weekend. The overall pattern suggests a
deepening mid level trough over the eastern USA for the second half
of this upcoming week. The largest detail differences involve the
evolution of a mid level cutoff somewhere between Hudson Bay and
Quebec. Our proximity to this particular feature will play a role in
how much lift can be used to generate cold advection showers across
our region. The guidance also suggesting a prominent mid level storm
track to our south late this week into early next week. Some
guidance suggested the possibility of a fast-moving low pressure
zipping by this weekend, which would enhance precipitation chances.
Still have some doubts how close this low pressure can actually get
to our region.

Have the greatest confidence for snow across the higher terrain of
southern New England Wednesday, with a snow-to-rain transition at
the lower elevations. Once this low pressure to our north and west
passes by, the mode of precipitation is expected to transition to
more of a cold advection showery pattern Thursday into Saturday.
While the possibility of a passing shower cannot be completely
dismissed, there should be many dry hours during this time,
especially Thursday and Friday. Will need more time to figure out
the precise track of a possible low pressure Saturday into Sunday.
Should it pass close enough to our region, we would see a greater
risk for a more widespread light snow at night, and more light rain
mixing in during the daytime. Not looking like a blockbuster storm
at this point, should it even materialize at all. A high pressure
should take over once more early next week.

Temperatures are anticipated to be below normal late this week into
early next week.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...

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

18Z TAF Update:

Today through Tuesday... High Confidence.

Dry and VFR, occasionally lower end VFR ceilings across terminals in
eastern Massachusetts through sunset. Gusty NW to NNW winds, gusting
between 20-25 knots, then diminishing after 21z. Light northerly wind
tonight becoming calm. Wind direction on Tuesday starts out of the
west less than 5 knots, becoming south-southwest 8-12 knots after
15z.

Tuesday Night... Moderate Confidence.

VFR, lowering to MVFR/IFR, isolated to scattered snow and/or rain
showers possible after 00z through 06z, with minor accumulation on
runways less than an inch. Wind from the southwest are gusting up to
15 knots over land and 25-30 knots over the coastal terminals.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Wednesday through Friday/...

Tuesday Night: Mainly VFR, with areas MVFR possible. Windy with
gusts up to 35 kt. Chance SN.

Wednesday: Mainly VFR, with local IFR possible. Windy with
local gusts up to 30 kt. Chance RA, chance SN.

Wednesday Night: Mainly VFR, with local IFR possible. Windy
with local gusts up to 30 kt. Chance RA, chance FZRA.

Thursday through Thursday Night: VFR. Breezy.

Friday: VFR. Breezy. Slight chance SN.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Tuesday Night... High confidence.

As high pressure builds in from the west, gusts diminish, falling
below advisory criteria this afternoon. Residual sea state with seas
4 to 6 feet remain through the first half of the overnight. Shifting
wind direction Tuesday, becoming southwest with gusts 15-20 knots by
late morning, 30+ knots Tuesday night, as a fast moving system
brings near Gale Force conditions into Wednesday. Seas are building
Tuesday night, 5-8 feet across southern waters, and 4-6 feet for the
eastern waters.

Outlook /Wednesday through Friday/...

Tuesday Night: Low risk for gale force winds with gusts up to
35 kt. Local rough seas. Chance of rain.

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Chance of rain.

Wednesday Night: Strong winds with gusts up to 35 kt. Areas of
rough seas. Chance of rain.

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Slight chance of rain.

Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Areas of rough seas. Slight chance of
snow.

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Local rough seas. Slight chance of rain, slight
chance of snow.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ231-
     235-237-251.
     Small Craft Advisory until 4 AM EST Tuesday for ANZ250-254>256.

&&

$$

SYNOPSIS...Belk/Dooley
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...Belk
AVIATION...Belk/Dooley
MARINE...Belk/Dooley