853
FXUS61 KBOX 211111
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
711 AM EDT Fri Mar 21 2025

.SYNOPSIS...
Once the rain ends today it will become windy with seasonable
temperatures. Dry and mild on Saturday with some scattered showers
possible later Saturday afternoon. A cold front moves through
Saturday night bringing windy and cooler conditions through Sunday.
Another round of precipitation is expected early Monday into early
Tuesday with mainly rain, but perhaps a period of wet light snow
across parts of the interior early Monday morning. Another system
moves through on Wednesday bringing back precipitation chances.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Messages...

* Rain moves out by noon with increasing sun through the day.

* Winds ramp up behind the rain, gusting 30 to 40 mph.

Rain continues to move from south to north over SNE as it shifts
east ahead of the cold front currently in eastern NY. The front will
relatively quickly move east through the region pushing the moisture
and rainfall out of western MA/CT by mid morning and eastern MA by
noon/early afternoon. A much drier airmass quickly moves overhead
allowing for clearing skies; by mid morning western areas should see
plenty of breaks of sun. By evening all of SNE, save perhaps for the
outer Cape and Nantucket, will see clear skies. Besides the cooler
air that arrives on that NW flow (highs back in the low 50s) cold
advection will also serve to increase the mixing down of a 30 to 40
kt LLJ. Expect wind gusts of 30-40 mph between 8 AM and 11 PM,
peaking in the afternoon.

&&

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

* Mainly dry & milder Sat with highs well up into the 50s.

* Dry except for a brief spot shower or two across the interior.

A mid level ridge moves overhead tonight and early Saturday leading
to mostly dry conditions. The exception may be Saturday evening when
a trailing cold front swings through, leading to increasing clouds
late in the day. Besides increased cloudcover, we may see some
widely scattered showers accompany the front. Coverage would be
limited thanks to minimal moisture available (PWATs near 0.4") but a
few quick hitting showers are possible thanks to forcing from the
surface front and mid level trough.

&&

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

* Mainly dry & milder Sat with highs well up into the 50s with
  nothing more than a brief spot shower or two across the interior

* Dry but blustery & colder Sat night into Sun

* Rain on tap for Mon perhaps beginning as a brief period of wet
  snow mainly across portions of the interior

* Potential for another system Wednesday bringing next chance for
  precipitation. Uncertainty in details.


Saturday Night - Sunday:

A cold front accompanies the trough passage Saturday night with
gusty NW winds developing behind it. Gusts 30-40 mph possible
overnight into Sunday. Cooler airmass than Saturday overhead which
will result in highs around or just below normal in the 40s.

Sunday Night - Wednesday:

There`s good agreement among model guidance for an upper level
trough and associated low pressure to push across the Great Lakes
region and toward New England overnight Sunday through Monday.
Guidance depicts New England in the left exit region of the upper
jet coupled with a plume of anomalous moisture. This will support
another round of precipitation to the region. Precipitation chances
gradually increase early Monday morning from west to east,
continuing through late Monday night/early Tuesday.

There are still some details with the system that are in lesser
agreement among model solutions and runs. Mainly with respect to
track/timing and cold air availability ahead of the system. This
will play into the potential for light wet snow at the onset of the
system that ensembles are signaling at. Ensembles show probabilities
for a trace to light snow accumulation across the interior, mainly
MA. Ensembles show generally a 20-60% chance for seeing over an 1"
north of the Mass Pike. The higher probabilities (60%+) are confined
to the higher elevations such as the Berkshires and northern border
of central MA. This period of snow will be likely short-lived as the
vertical column warms into mid-morning Monday as the warm front
progresses north. There is a low chance for some flakes to mix in
further east, but will depend on the timing of the system with the
cold air. The rest will be rain that continues through Monday night.

Tuesday and Wednesday:

Conditions trend drier Tuesday behind Monday`s system with highs in
the 40s and low 50s. Ensemble guidance shows another shortwave
trough moving across mid-week that could bring some precipitation to
southern New England. Details still need to be ironed out especially
with the track which will impact QPF and precipitation chances.

&&

.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

12z TAF Update...

Moderate confidence.

Expect improving conditions by late morning/early afternoon
with VFR developing everywhere.. However NW winds will gust
25-35kt in most areas, especially after 16-18z. VFR continues
Friday night, with winds diminishing.

Saturday VFR continues with winds out of the SW 10 to 15 kts
with gusts of 20 to 25 kts.

KBOS TAF...Moderate Confidence in TAF.


KBDL TAF...Moderate confidence in TAF.

Outlook /Saturday Night through Tuesday/...

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

Sunday: VFR. Breezy.

Sunday Night: VFR. Breezy. Chance SN.

Monday: Mainly MVFR, with local IFR possible. Breezy. RA.

Monday Night: VFR. Breezy. Chance RA.

Tuesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

A fast moving low pressure moves across the region early this
morning. Cold front passes through early this morning, with a wind
switch to the NW. Expect those winds to become rather gusty -- up to
30kt after the front and especially Friday afternoon and early
evening. Thus the Small Craft Advisories will remain in place. Winds
diminish overnight but will gust 20-25 kts on Saturday. Seas of 4-6
kts today will continue through Saturday.

Outlook /Saturday Night through Tuesday/...

Saturday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Seas up to 5 ft.

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Local rough seas.

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

Monday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Areas of rough seas. Rain.

Monday Night: Winds less than 25 kt. Areas of rough seas. Rain
likely.

Tuesday: Winds less than 25 kt. Areas of rough seas.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ235-
     237.
     Small Craft Advisory until 8 AM EDT Saturday for ANZ250-
     254>256.
     Small Craft Advisory until 2 AM EDT Saturday for ANZ251.

&&

$$

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