571
FXUS61 KBOX 111710
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1210 PM EST Thu Dec 11 2025

.SYNOPSIS...
Much colder air works into the region today and tonight on
westerly wind gusts of 35 to 50 mph. Wind chills will drop
to between 5 below and 10 above tonight. Cold and
blustery conditions continue Friday...but a ridge of high
pressure allows winds to diminish Friday night and Saturday
despite the continuation of chilly temperatures. A period of
snow is possible late Saturday night into Sunday...but that
remains uncertain and depends if low pressure tracks far enough
north. Regardless...another shot of arctic air follows Sunday
night into Monday with wind chills dropping to between 5 below
and 10 above. A pattern change is expected by the middle of next
week resulting in significantly milder temperatures.

&&

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

* Wind Advisory expanded to include the rest of our county warning
  area

* Steep pressure gradient and strong low level jet brings widespread
  35-50 mph gusts

* Cold and blustery conditions will support single digit wind chill
  temperatures Thursday night

Strong CAA regime will bring a period of strong, and even
locally damaging wind gusts today and tonight. Guidance
continues to show average winds of 35 knots in a well- mixed PBL
tomorrow. Wind speeds at the top of the PBL may even increase
to as high as 50-55 mph later today. BUFKIT soundings have
maximum mixed layer heights between 4-6 kft and 1000-850mb lapse
rates >9C/km. In short, all ingredients are there for a strong
wind event with peak gusts in the 35-40 knot range for much of
Southern New England. As a result, opted to expand the wind
advisory for all locations through Friday morning.

In addition to the strong winds, we`ll see a significantly colder
temperatures Thursday. High temps peak in the 30s around midnight
Thursday then bottom out in the middle to lower teens Friday
morning. Low temperatures combined with strong west/northwest winds
will result in wind chill readings falling to the the single digits
Friday morning for much of the region except for the Cape and
Islands where readings will be closer to the lower teens.

&&

.SHORT TERM /FRIDAY/...
Wind advisory will remain in effect through 15z Friday as the
strongest part of the LLJ moves offshore. Expecting a frigid
start to the day with NW winds around 20-40 mph leading to wind
chills in the single digits above and below zero with the
coldest values in the higher terrain. Slow improvements in wind
chills through the day with gradually warming temperatures. .

&&

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

* Dry & chilly Fri night into Sat with lows mainly in the teens and
  highs generally in the 30s...but parts of RI/SE MA may approach 40

* A period of snow possible late Sat night-Sun if low pressure
  tracks far enough north...but that still remains uncertain

* Another shot of arctic air follows later Sun/Sun night with windy
  conditions and high temps Mon only reaching the 20s

* Still cold Mon night-Tue with highs in the upper 20s-middle 30s
  with perhaps a few brief snow showers

* Pattern change with a warming trend expected Wed and especially
  Thu when highs may reach well into the 40s to near 50

Details...

Friday night and Saturday...

A weak ridge of high pressure to our south will take control of our
weather. The result will be dry weather with relatively light winds.
Low temperatures will mainly be in the teens Fri night with highs on
Sat generally in the 30s...but some places across RI/SE MA may
approach 40.

Saturday night and Sunday...

There still remains quite a bit of uncertainty later Sat night and
Sun depending on the track of a fast moving low pressure system. If
the system tracks far enough we will see a period of snow...but it
may stay far enough south where most if not all our region remains
dry. Regardless...this does not look like a big event but certainly
the risk for a few inches of snow if this system ends up tracking
far enough north.

The guidance has been struggling with this over the past couple of
days. Strong northern stream shortwave energy will be diving
southeast across the Great Lakes. Timing and amplitude of this
shortwave will impact how far north low pressure emerging off the
mid-Atlantic coast will track. Currently...most of the guidance has
just a glancing blow mainly south of I-90 and the greatest risk near
the south coast. However...certainly would not take much of a bump
northward to bring the risk for a few inches of snow to much of
southern New England. This scenario is shown by the 00z NAM as well
as some of the individual GEFS/EPS/CMC ensembles. So in a
nutshell...the northern extent of this snow shield remains
uncertain. We probably need a few more model runs to sort this out.
Regardless of what happens...this system will be progressive so not
expecting a major event.

Sunday night into Monday...

Regardless of what happens with the low pressure system Sat night
into Sun...a cold front will usher in another short of arctic air
Sun night into Mon. Low temps Sun night should bottom out mainly in
the high single digits and teens with highs on Mon mainly in the
20s. Windy conditions will result in wind chills dropping into the 5
below to 10 above range late Sunday night into early Monday morning.

Monday night and Tuesday...

Still cold Mon night and Tue but with diminishing wind. Some of the
guidance indicates a shortwave that may result in a few snow
showers. Otherwise...Lows Monday night mainly in the teens with
highs Tuesday in the upper 20s to the middle 30s.

Wednesday and Thursday...

Appears most of the long range guidance is an agreement in a pattern
change. A developing -PNA allows more of a zonal flow of Pacific air
to work across the U.S. Highs probably reach into the 40s across
much of the region Wed with perhaps some areas reaching 50 by Thu.
So this will be significantly milder weather than what we have been
experiencing so far in December.

&&

.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...

Through tonight...High Confidence

VFR. Westerly wind gusts of 30-40 knots continue through
tonight. A few gusts up to 45 knots possible especially in the
high terrain.

Friday...High Confidence

VFR. Westerly wind gusts of 25 to 35 knots.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Friday Night through Monday/...

Friday Night: VFR. Windy with local gusts up to 30 kt.

Saturday: VFR. Breezy.

Saturday Night: VFR. Breezy. Chance SN.

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

Sunday Night through Monday: VFR. Windy with gusts up to 35 kt.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today Through Friday...High confidence.

Strong CAA brings westerly gales for all the waters continuing
through Friday. Near storm force westerlies tonight into Friday
morning. Gales gradually relax after 18z Friday afternoon.

Outlook /Friday Night through Monday/...

Friday Night: Low risk for gale force winds with gusts up to
35 kt. Areas of seas approaching 5 ft.

Saturday: Winds less than 25 kt.

Saturday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain, chance of snow.

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Areas of seas approaching 5 ft. Snow likely, chance
of rain. Visibility 1 to 3 nm.

Sunday Night: gale force winds with gusts up to 45 kt. Areas of
rough seas. Chance of snow showers. Local visibility 1 to 3 nm.

Monday: Low risk for gale force winds with gusts up to 40 kt.
Areas of rough seas.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory until 10 AM EST Friday for CTZ002>004.
MA...Wind Advisory until 10 AM EST Friday for MAZ002>024-026.
RI...Wind Advisory until 10 AM EST Friday for RIZ001>008.
MARINE...Gale Warning until 1 PM EST Friday for ANZ230>237-251.
     Gale Warning until 7 PM EST Friday for ANZ250-254>256.

&&

$$

SYNOPSIS...Frank/FT
NEAR TERM...FT
SHORT TERM...FT
LONG TERM...Frank
AVIATION...McMinn
MARINE...Frank/FT