Lynn, Massachusetts 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

487
FXUS61 KBOX 201712
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1212 PM EST Sat Dec 20 2025

.WHAT HAS CHANGED...
No significant changes. Gusty winds will quickly diminish this
morning.

&&

.KEY MESSAGES...

- Quiet conditions today before wind gusts resume tonight

- Turning colder and blustery late Sunday into Monday

- Light snow accumulations possible Tue

- Warming trend for the end of the week

&&

.DISCUSSION...
KEY MESSAGE 1...Quiet conditions today before wind gusts resume
tonight

Winds diminish quickly this morning, then turn SW this afternoon
as high pres moves to the mid Atlc coast and gradient relaxes.
Expect plenty of sunshine today with high clouds increasing a
bit this afternoon in developing WAA pattern. Near seasonable
temps.

Pressure gradient increases tonight ahead of a cold front
approaching from the west. Gustiness will return later tonight,
especially over higher terrain and along immediate coast where
SW gusts to 25-35 mph expected. 15-25 mph gusts elsewhere.
Clouds increase tonight but dry weather will prevail with steady
or slowly rising temps overnight as winds increase.

KEY MESSAGE 2...Turning colder and blustery late Sun into Sun night

Strong cold front will be moving through SNE from late morning
through the afternoon. Moisture is limited and none of the guidance
is indicating any precip so expect a mostly dry fropa. The front
will be preceded by a period of gusty SW winds late tonight into Sun
morning, mainly along the immediate south coast and Cape/Islands. We
have a modest low level jet which will be moving offshore but
soundings do show a shallow mixed layer enough for some gusts to 25-
35 mph, strongest over the Islands. Behind the front, strong cold
advection and deepening boundary layer will support similar 25-35
mph gusts late Sun into Sun night, with the strongest winds over the
higher elevations. Winds gradually diminish through Monday.
Seasonable temps Sun ahead of the front then falling temps behind
the front Sun afternoon, especially interior and turning much colder
Sun night as 850 mb temps bottom out at -12 to -15C. Wind chills by
Mon morning will drop to 5-10F and near zero in the Berkshires.
Temps will be several degrees below normal Mon with highs upper
20s and lower 30s and plentiful sunshine in very dry airmass.

KEY MESSAGE 3...Light snow accumulations possible Tue

A fast moving shortwave in NW flow aloft with warm front
approaching from the SW and decent isentropic lift will bring a
period of precip to SNE. Still some uncertainty with timing and
when precip begins but highest confidence is during Tue. Column
is cold enough snow as moisture moves into the region so expect
a period of light snow for all SNE. The uncertainty is with the
extent of boundary layer warming and any transition to rain.
Best chance of a changeover will be near the south coast but
this is not looking like a significant QPF event. Global
ensembles do show moderate to high probs (>70%) for 1" or
greater across the interior with lower probs near the coast,
while there are low probs (<20%) for 3". So preliminary
estimates are for an inch or 2 accum with best chance in the
interior.

KEY MESSAGE 4...Warming trend for the end of the week

Amplifying northern stream trough moves to the east Wed then broad
ridging develops across the central and eastern CONUS which will
result in a warming trend through the end of the week. Temps will be
near or a bit below normal Wed then warming above normal Thu and
especially Fri when temps could make a run at 50F. Weak shortwave
around Christmas Day may bring some shower activity but better
chance will be Fri as more robust shortwave approaches. Any precip
during the end of the week will be mostly rain in warming
environment.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...no significant changes.

Tonight through Saturday...High Confidence in trends

VFR conditions expected. SW winds through this afternoon and
tonight. SW gusts 25-30 kts resume late tonight into Sunday
morning, mainly along the immediate coast and Islands and higher
terrain.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday through Wednesday/...

Sunday: VFR. Windy with areas of gusts up to 30 kt.

Sunday Night: VFR. Windy with gusts up to 30 kt.

Monday: VFR. Breezy.

Monday Night: VFR. Slight chance SN.

Tuesday: MVFR/IFR conditions possible. Breezy. SN likely,
chance RA.

Tuesday Night: Mainly VFR, with local IFR possible. Breezy.

Wednesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Tonight...High Confidence.

Winds diminish this morning and drop below 20 kt this
afternoon with subsiding seas. Another pulse of 25-35 kt SW
gusts develop tonight ahead of a cold front. Another round of
gale warnings will likely be needed for some of the waters.

Outlook /Sunday through Wednesday/...

Sunday: Strong winds with gusts up to 35 kt. Rough seas up to
11 ft.

Sunday Night: Strong winds with gusts up to 30 kt. Rough seas
up to 10 ft.

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

Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft.

Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Local rough seas. Rain likely. Local
visibility 1 to 3 nm.

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

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 AM EST Sunday for ANZ231>234-251-
     255.
     Small Craft Advisory until 1 AM EST Sunday for ANZ235-237-256.
     Gale Watch from late tonight through Sunday morning for ANZ235-
     237-256.

&&

$$

DISCUSSION...KJC
AVIATION...KJC/FT
MARINE...KJC