730
FXUS61 KBOX 022344
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
644 PM EST Mon Mar 2 2026

.WHAT HAS CHANGED...

Winter Weather Advisories posted for Tuesday afternoon to
Wednesday morning for interior Southern New England for light
accretion of icing and minor snow and sleet accumulation.
There is also increasing confidence on a period of a wintry mix
Thursday night into Friday across northern MA.

&&

.KEY MESSAGES...

- Wintry mix of snow, sleet and freezing rain brings slippery
  roads to interior Southern New England Tue afternoon and
  evening; brief wet snow changes to plain rain and minimal to
  nil impact for the MA/RI coastal plain.

- Dry and very pleasant weather arrives Wednesday, feeling mild
  with March sunshine, light winds and highs in the upper 40s to
  lower 50s.

- A period of wintry precip remains possible Thu night into
  early Fri.

- Pattern change towards milder weather this weekend and
  potentially warmer next week.

&&

.DISCUSSION...

215 PM Update:

KEY MESSAGE 1...Wintry mix of snow, sleet and freezing rain brings
slippery roads to interior Southern New England Tue afternoon and
evening; brief wet snow changes to plain rain and minimal to nil
impact for the MA/RI coastal plain.

Quasi-stationary frontal boundary lying across the OH Valley and mid-
Atlantic Piedmont region will lift northward on Tue, spreading
clouds and warm-frontal precipitation northward into Southern New
England Tue starting mainly during the early to mid-afternoon hours.
This precip will be falling into a retreating modified-Arctic
airmass coming out of another chilly night tonight. However the
combination of onshore/east flow and associated warming surface
temps along the coastal plain to go along with limited surface
heating before turning overcast during the morning hours could
offset evaporative/wet-bulb cooling until precip arrives. Given the
now-delayed arrival of precip and questions on how soon arrival of
clouds come in, how cold surface temps could still prove to be a
challenge; utilized some of the colder 2-m temps given the potential
for wet-bulbing which model-blended solutions tend to wash out or
not resolve as well.

We still expect a wintry mix of snow/sleet/freezing rain in interior
Southern New England during the afternoon and evening hours where
winter weather advisories have been posted from Tue noontime til
early Wed morning. The main impact in those areas is from icing,
with up to a tenth of an inch of ice accretion, and up to an inch of
combined snow/sleet accumulation at outset. It is somewhat
debatable/uncertain how much road impact there may be during
the Tue afternoon drive, and that`s especially the case if cloud
cover is slow to arrive and ends up permitting several hours of
strong early-March sun to warm up pavement; feel more confident
in at least slippery road conditions developing by the early
evening hours, as temps hover or slightly cool on light NE
drainage winds which will help sustain frozen p-types in
interior Southern New England until precip comes to an end Wed
morning.

In the coastal plain, a brief period of wet snow during the
early to mid afternoon Tuesday should mix over with rain with
temps in the mid 30s, then change to a plain rain for the
remainder of the evening where adverse road impacts should prove
minimal.

KEY MESSAGE 2...Dry and very pleasant weather arrives
Wednesday, feeling mild with March sunshine, light winds and
highs in the upper 40s to lower 50s.

Short wave ridging in fast flow aloft advects across SNE, providing
a very pleasant, dry Wed across SNE. Mild with highs in the upper
40s and low 50s. It feel even milder given light winds and full
March sunshine.

KEY MESSAGE 3...A period of wintry precip remains possible Thu
night into early Fri.

Fast, wavy zonal upper air pattern yields the next precip event for
SNE Thu night into Fri. 1040 mb anticyclone over southeast Quebec
into the Maritimes will yield a wedge of shallow cold air into SNE.
This will support the risk of a wintry mix this period, with highest
probs of an icy mix across northern MA. It`s possible this shallow
cold air could bleed farther south, with a low risk of a wintry mix
near or into the I-95 corridor. Just too early to tell, this needs
to be watched. Not a major winter event, but it only takes a small
amount of ice to impact travel. Stay tuned.

KEY MESSAGE 4...Pattern change toward milder weather this
weekend and potentially warmer next week.

Good multi-model agreement on a pattern change beginning this
weekend and continuing into next week, with a southeast/western
Atlantic ridge. This will promote SW up the eastern seaboard into
SNE, with temps rising into the low 50s Saturday, and possibly low
60s away from the south coast Sunday and Monday. Dew pts will be
rising into the low 50s then, so definitely a mild feel to the
airmass, along with accelerating the erosion of the the snow pack
with dew pts rising into the 50s and SW winds 10-15 mph providing
some mixing around the snowcover.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...

Forecaster Confidence Levels...

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

00z TAF Update...

Tonight...High confidence.

VFR. Light/calm winds.

Tuesday and Tuesday night...High confidence in trends with
moderate confidence in timing.

MVFR-IFR conditions overspread the region from southwest to
northeast in the 15z to 20z timeframe as precipitation
overspreads the region. Ptype initially mainly snow but a quick
change to rain from south to north in the 21z to 01z along the
coastal plain with perhaps a brief period of sleet during the
transition. However...across portions of the interior temps near
or just below freezing will result in snow/sleet transitioning
to pockets of light freezing rain by early Tue evening. IFR to
LIFR conditions expected Tue night with periods of rain along
the coastal plain with light freezing rain across parts of the
interior. Winds generally less than 10 knots Tue into Tue night.

KBOS Terminal...High confidence in TAF. Snow arrives near of
just after 19z and flips to rain by 23z with perhaps a brief
period of sleet during the transition. Little impact on runways
expected.

KBDL Terminal...High confidence in TAF. Snow arrives around
16z/17z and flips to light rain/freezing rain by 22z/23z with
perhaps a period of sleet during the transition. Temps Tue
evening will be near freezing...so impacts may be somewhat
limited on runways but some icing can not be ruled out.

Outlook /Wednesday through Saturday/...

Wednesday: VFR. Slight chance RA, slight chance FZRA.

Wednesday Night: VFR. Slight chance SN.

Thursday: Mainly VFR, with local IFR possible. Chance RA.

Thursday Night: MVFR/IFR conditions possible. Breezy. Chance
RA, FZRA likely.

Friday: MVFR/IFR conditions possible. Breezy. RA likely, FZRA
likely.

Friday Night: MVFR/IFR conditions possible. Slight chance RA.

Saturday: Mainly VFR, with areas IFR possible. Breezy. Slight
chance RA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Tuesday Night...High confidence.

Winds and seas remain below small craft advisory thresholds
through at least Tuesday afternoon, with south to southeast
winds around 10-15 kt. Seas may begin to build late Tuesday
night into Wednesday to around 4-6 ft on the southeast outer
waters, which could prompt small craft advisories. Reduced
visibilities possible in snow to rain Tuesday afternoon.

Outlook /Tuesday Night through Saturday/...

Wednesday: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain, slight chance of freezing rain.

Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Slight chance of rain.

Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain.

Thursday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Rain likely.

Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas. Rain likely.

Friday Night through Saturday: Winds less than 25 kt. Areas of
rough seas. Slight chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Weather Advisory from noon Tuesday to 7 AM EST
     Wednesday for CTZ002>004.
MA...Winter Weather Advisory from noon Tuesday to 7 AM EST
     Wednesday for MAZ002>012-014-026.
RI...Winter Weather Advisory from noon Tuesday to 7 AM EST
     Wednesday for RIZ001.
MARINE...None.

&&

$$

DISCUSSION...Loconto/Nocera
AVIATION...Frank/Loconto/Nocera
MARINE...Loconto/Nocera