544
FXUS61 KBOX 282320
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
720 PM EDT Fri Mar 28 2025

.SYNOPSIS...
Periods of unsettled weather are on tap late tonight through
this weekend with a backdoor cold front mainly to our south.
Overall, we expect a chilly and raw weekend with showers or
drizzle at times. Even some light freezing rain or freezing
drizzle is possible across the Berkshires and northern Worcester
Hills. Much of our region may finally warm up by Monday with
another round of showers, and perhaps some downpours, associated
with an approaching cold front. Drier weather should return
Tuesday and Wednesday as high pressure builds into the region
with temperatures trending colder.

&&

.NEAR TERM /THROUGH SATURDAY/...
720 PM update...

Very dry air persists across SNE. Dewpoints still in the teens
and 20s with large T/Td depressions. Soundings also show the dry
air below 850 mb. Will take a bit of time to moisten the low
levels so while there may be a few sprinkles later this evening,
the steadier rain will likely be delayed until midnight or
later.

Previous discussion...

Key Messages:

* A complex system arrives tonight and will be with us through
  this weekend which brings periods of rain and the
  possibility of sleet and freezing rain or sleet to northern
  Massachusetts.

A warm front arrives later tonight before getting stuck
somewhere across southern New England. Temperatures will
greatly depend upon how far north this front can get exactly.
Periods of rain overspread the region after sunset as waves of
low pressure traverse this boundary. There is a low chance of
freezing rain or freezing drizzle just before sunrise, mainly
for border towns in northern Worcester and northeast Middlesex
Counties, where the low temperatures will flirt with the
freezing mark. Given the isolated nature of this icing threat
and confidence of it occurring, have held off on issuing a
Winter Weather Advisory at this time.

&&

.SHORT TERM /SATURDAY NIGHT/...
Key Messages:

* There is still significant uncertainty with the exact position
  of a stationary front for Saturday. Areas north of this front
  will be rather cold, while areas south are mild.

* Greater risk for freezing rain or freezing drizzle Saturday
  night

The main forecast challenge Saturday will be the exact location
of a nearly stationary front. This front should waffle north
and south slightly as wave of low pressure move by. In general,
thinking this front will be mainly south of the Mass Pike. The
12Z 3km NAM had the best representation of the tightness of the
gradient, but perhaps not the best location.

Large bust potential with temperatures. The latest NationalBlend
still had very large ranges between the 10th and 90th
percentiles. Although the range had decreased from prior
forecasts across northeast MA to about 8F, there still was about a
25F spread from central MA into CT. It is not uncommon for
backdoor cold fronts this time of year to push farther south. The
large ranges in the guidance highlights this possibility.
Favored a colder solution for temperatures Saturday.

Not looking like the best day Saturday. Areas of showers and
drizzle through much of the day, especially north of this front.
This continues into Saturday night, when the possibility of some
freezing rain or freezing drizzle develops across the northern
Worcester Hills and the Berkshires. Winter Weather Advisories
may be needed for this icing threat.

&&

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

* Continued cool and raw Sun with a few showers or drizzle at
  times, especially north of the MA Pike. Pockets of freezing
  rain/drizzle possible Sun morning over higher elevations north
  of Route 2.

* Turning milder Mon with a period of showers Mon into Mon night.
  Perhaps a rumble of thunder and downpours possible.

* Dry Tue & Wed with a cooling trend to below normal temps

* Perhaps some unsettled weather returns by Thu or Fri, but low
  confidence at this time

Details...

Sunday into Monday night...

Unsettled period with multiple rounds of wet weather along with
moderating temps Monday. For Sunday, SNE will remain on the cool
side of the boundary which will set up to the SW. Continued
easterly flow will hold temps in the 40s for most locations,
possibly reaching lower 50s toward Hartford, with highs only
near 40 north of Route 2. Occasional showers or drizzle at
times, especially north of the MA Pike where better moisture is
available, while locations near the south coast may remain
mostly dry Sunday as some drier air moves up from the south.
Still could see some pockets of freezing rain/drizzle in the
morning over higher elevations north of Route 2 where temps will
hover around freezing.

More of the same Sun night but the surface boundary will begin
to move northward into SNE as a warm front as increasing SW low
level jet develops. More drizzle and showers at times along with
areas of fog which could be locally dense as higher dewpoint air
advects into the region.

Then by Monday, the warm sector overspreads the region as the
front lifts to the north. This will allow milder temps reaching
the 60s away from the south coast. The guidance is indicating a
dry slot moving into the region late Sun night into Mon morning
which could result in a lull in shower activity with a round of
more widespread showers being delayed until Mon afternoon and
especially Mon night as the cold front moves through. Some
uncertainty with the timing of this front although GFS is likely
too quick. Decent pre-frontal low level jet 50-60 kt with PWATs
approaching 1.5" so expect some locally heavy downpours and
can`t rule out a rumble of thunder. We will have a strong low
level inversion in place across SE New Eng where the axis of the
low level jet sets up. This will prevent strong winds from
mixing to the surface but should see some gusty winds to 30 kt.

Tuesday through Friday...

Front moves offshore by early Tue with much drier and cooler
conditions overspreading the region, then high pres builds to
the north and east Wed. Expect dry conditions Tue-Wed with temps
trending to below normal. Then pattern looks to become unsettled
again for the end of the week as a frontal system approaches.
Low confidence on specific details but risk for showers will
increase Thu-Fri and there may be enough low level cold air at
the onset for some mixed precip in the interior.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Tonight...Moderate Confidence.

VFR to start, then trending to MVFR/IFR after midnight with
areas of light rain developing.

Saturday and Saturday Night...Moderate Confidence.

Mix of VFR/MVFR across CT and RI, trending to more MVFR/IFR
elsewhere. Areas of light rain or drizzle as well. Possibility
of some -FZRA/-FZDZ after 04Z Sunday across the northern
Worcester Hills and towards the Berkshires.

BOS TAF...High confidence in TAF.

BDL TAF...High confidence in TAF.

Outlook /Sunday through Wednesday/...

Sunday: Mainly IFR, with areas VFR possible. Chance RA, chance
FZRA.

Sunday Night: MVFR/IFR conditions possible. Breezy. Chance
SHRA, patchy BR.

Monday: MVFR/IFR conditions possible. Windy with local gusts up
to 30 kt. SHRA likely.

Monday Night: Mainly MVFR, with local IFR possible. Windy with
local gusts up to 30 kt. SHRA.

Tuesday through Tuesday Night: VFR. Breezy.

Wednesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Saturday Night: High Confidence.

A approaching front stall across the waters tonight and lingers
into Saturday night. ENE winds across the eastern waters, with W
to SW winds across the southern waters. Not likely to see wind
gusts up to 25 kt, but do expected rough seas to develop across
the outer coastal waters. Small Craft Advisories posted for late
tonight into Saturday night.

Outlook /Sunday through Wednesday/...

Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Chance of rain. Local visibility 1 to 3 nm.

Sunday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.

Monday: Strong winds with gusts up to 30 kt. Rough seas up to
9 ft. Chance of rain showers, isolated thunderstorms.

Monday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Rough seas up to 10 ft. Rain showers,
isolated thunderstorms.

Tuesday: Winds less than 25 kt. Areas of rough seas. Slight
chance of rain showers.

Tuesday Night: Winds less than 25 kt. Seas up to 5 ft.

Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 11 AM Saturday to 7 AM EDT Sunday
     for ANZ235-237-254.
     Small Craft Advisory from 2 PM Saturday to 4 AM EDT Sunday for
     ANZ250.
     Small Craft Advisory from 5 AM Saturday to 7 AM EDT Sunday for
     ANZ255-256.

&&

$$

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