412
FXUS61 KBOX 040552
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1252 AM EST Thu Dec 4 2025

.SYNOPSIS...
Dry and cold weather persists tonight. An arctic cold front crosses
the region Thursday with a few snow showers and perhaps a localized
heavier snow squall...followed by windy and bitterly cold
temperatures Thursday night. The winds quickly diminish by Friday
but it remains unseasonably cold. Scattered snow showers possibly
mixing with rain showers may impact the region late Friday night
into Saturday with a low pressure system passing well to our south.
Another arctic cold front crosses the region Sunday followed by well
below normal temperatures Sunday night into Tuesday. A low pressure
system approaching from the west may bring some more rain/snow
showers by Tuesday night and/or Wednesday.

&&

.NEAR TERM /THROUGH TODAY/...
Key Messages...

* Dry & cold tonight with lows mainly in the upper teens and 20s

Details...

Tonight...

A moisture starved shortwave will be crossing the region tonight.
The atmosphere is too dry to support any precipitation...but we will
see some mid level cloudiness working across the region. So dry and
cold weather is on tap for tonight with low temps mainly in the
upper teens and 20s with some lower 30s in the urban heat island of
Boston.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
Key Messages...

* Arctic cold front brings a few snow showers/gusty winds Thu with
  perhaps a brief localized snow squall or two...Highs 35 to 40

* Windy & bitterly cold Thu night...Lows mainly in the single digits
  to the middle teens with Wind Chills between 10 below & 10 above

* Mostly sunny/light wind & unseasonably cold Fri...Highs 20s/near 30

Details...

Thursday...

An arctic cold front will be crossing the region Thursday afternoon.
A mixture of clouds and sunshine ahead of this front should result
in highs mainly between 35 and 40...which is still below normal for
this time of year. As the front crosses the region...shortwave
energy coupled with 0-2 KM ThetaE lapse dropping below zero along
with a touch of MUCape are favorable for a few brief snow showers
and perhaps a localized snow squall or two. The one thing we are
lacking is low level moisture...so this may keep the snow squall
threat rather localized but something we still need to watch. As
this front crosses the region...NW winds will increase and expect
gusts of 25-40 mph to develop by mid-late afternoon.

Thursday night...

A bitterly cold airmass will invade the region as 925T drop to
between -15C and 18C...which is quite impressive for the first week
of December! This will be accompanied by NW wind gusts of 25 to 40
mph in the evening...which should diminish later Thursday night. Low
temps should bottom out mainly in the single digits to middle teens
in most locations. In fact...if the winds diminish enough may even
see a few sub-zero readings across the outlying locations of
northwest MA with the snowpack in place. While we are not expecting
the need for any Cold Weather Advisories...wind chills will drop to
between 10 below and 10 above zero late Thursday night!

Friday...

Large high pressure builds into southern New England from the west
on Friday. This will result in plenty of sunshine along with light
winds but with unseasonably cold temperatures. Despite temps
beginning to warm aloft...limited mixing and low December sun angle
should keep highs in the 20s to near 30. These numbers are well
below normal of this time of year.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Key Messages...

*  Scattered snow showers possible late Fri night-Sat perhaps even
   changing to rain showers near the I-95...snow accums look minor

* Highs this weekend in the 30s to lower 40s...still below normal

* Another shot of arctic air Sun night into Tue with highs returning
  to well below normal mainly in the 20s to the lower 30s

* Scattered snow showers possible Tue night-Wed perhaps mixing with
  or changing to rain showers

Details...

Friday night and Saturday...

High pressure moves east of the region as a weak wave of low
pressure tracks off the mid-Atlantic coast Fri night into Sat. Given
the lack of amplitude in the upper level flow...this low pressure
system will pass well to our south. Therefore...mainly just
expecting the risk of scattered snow showers which may even change
to rain showers near I-95 given lack of cold high in eastern Canada.
Either way...snow accumulations should be on the minor side.

The one fly in the ointment Fri night into Sat is the potential for
an inverted trough to setup. This can sometimes result in a very
narrow band of more significant precipitation. Low risk at this
point...but something to watch in the late Friday night-Saturday
time frame. Highs should be in the 30s to near 40 on
Saturday...which is still below normal for this time of year.

Sunday through Tuesday...

Another arctic cold front will cross the region later Sun into Sun
night. While high temperatures on Sunday should still reach the 30s
to the lower 40s...it will be turning much colder Sunday night into
Tuesday. Low temps should be mainly in the single digits and teens
with highs mainly in the 20s to the lower 30s...which is well below
for early December standards. Generally dry weather expected over
this time outside perhaps a brief passing flurry/snow shower or two
late Sun with the arctic cold front.

Tuesday night and Wednesday...

Low pressure approaching from the west may bring another round of
scattered snow showers sometime Tue night into Wed. Currently this
does not look to be a significant storm and may even see enough warm
air enter the picture for a change to rain showers in some
locations. This all is certainly subject to change given the time
range.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Forecaster Confidence Levels...

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

06Z TAF Update...

Today and Tonight...High confidence. Moderate for snow shower
chances.

Mainly VFR conditions. An arctic cold front may bring a few
snow showers and the low chance for a localized snow squall or
two in the afternoon. This would bring brief localized lower
cigs/vsbys. Due to the very scattered nature of the showers,
confidence isn`t high enough to include snow showers in TAF.
Highest chances for seeing a shower/flurry or isolated squall
will be in the afternoon.

WSW winds today with gusts 20-25 kts. Front moves through 18-22Z
with winds shifting to WNW/NW with gusts increasing to 25-35
Winds. Winds gradually diminish late Thursday night into early
Friday.

Friday...High confidence.

VFR. Light winds becoming SW at 5-10 knots.

KBOS Terminal...High confidence in TAF. Moderate for SNSH
chances.

KBDL Terminal...High confidence in TAF. Moderate for SNSH
chances.

Outlook /Friday Night through Monday/...

Friday Night: Mainly VFR, with local MVFR possible. Slight
chance FZRA, slight chance SN.

Saturday: Mainly VFR, with local MVFR possible. Chance RA,
chance SN, chance FZRA.

Saturday Night through Sunday: VFR.

Sunday Night: VFR. Breezy. Slight chance SN.

Monday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight through Friday night...High confidence.

* Gale Warnings Thu afternoon and night

The main concern will be an arctic cold front that crosses the
region on Thursday. This will bring NW wind gusts of 30 to 40 knots
Thursday afternoon and night. This has prompted the issuance of Gale
Warnings for our waters given excellent mixing given the amount of
cold air crossing the relatively warm waters. High pressure quickly
builds in from the west Fri allowing winds/seas to diminish
significantly.

Outlook /Friday Night through Monday/...

Friday Night: Winds less than 25 kt. Chance of rain, slight
chance of freezing rain.

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

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. Slight chance of rain, slight chance of snow.

Monday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Seas up to 5 ft. Slight chance of snow.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Gale Warning from 4 PM this afternoon to 1 AM EST Friday for
     ANZ230-236.
     Gale Warning from 1 PM this afternoon to 4 AM EST Friday for
     ANZ231>235-237-250-251-254>256.

&&

$$

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