Area Forecast Discussion
Issued by NWS Boston, MA

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768
FXUS61 KBOX 311047
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
647 AM EDT Sat Oct 31 2026

.WHAT HAS CHANGED...

No significant changes to the forecast.

&&

.KEY MESSAGES...

- Breezy and cool conditions expected for Halloween.


- High pressure maintains quiet weather through at least
  Thursday with warmer than average highs in the 60s.

&&

.DISCUSSION...

KEY MESSAGE 1...Breezy and cool conditions expected for
Halloween.

A cooler day is expected today as the post-frontal
air mass moves in. Aloft, 925 mb temperatures cool to around 0C
and NW winds continue, yet weaken with high pressure building
in. Highs on Halloween will only reach the 50s as a result.
Skies clear, and winds falling to or near calm Halloween night
will allow for radiational cooling, dropping lows to the 20s and
low 30s for much of the region. As is normally the case, the
coldest readings will be found across the far interior where
lows fall to near 20 degrees.

KEY MESSAGE 2...High pressure maintains quiet weather through
at least Thursday with warmer than average highs in the 60s.

High pressure will remain firmly in control of southern New
England`s weather clear through at least mid to late week as this
stretch of pleasant weather continues. A large high moving in from
New York will initially move overhead on Sunday, replaced by another
dropping south from Canada into Maine mid week. A weak trough will
pass over the Canadian maritimes around Tuesday bringing the
potential for some showers to northern New England but lack of
moisture and dynamics over SNE will keep us dry. The next chance for
a pattern change comes around late Thursday/Friday when a mid level
trough may dig into the mid-Atlantic, but that is not a certainty at
this point. EPS and GEFS ensembles paint a 70-90% chance of PWATS
climbing above 1" Thursday-Saturday next week. Run to run
variability shows less of a signal for QPF with the latest members
showing probs of >0.5" of 24 hr QPF falling from 60-70% for the 12z
runs to 30-50%. In the mean time, high pressure maintains a milder
than average airmass overhead leading to comfortable highs in the
60s all week. Winds should be light until Friday when our passing
low would bring a period of gusty winds.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...

Forecaster Confidence Levels...

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

12z TAF Update...

Today and Tonight...High confidence.

VFR. NW winds around 7-14 kt with a few gusts in the lower 20
knot range through lunchtime, with gusts easing in the
afternoon. Winds then go light WNW/calm overnight.

Sunday...High confidence.

VFR. WSW winds of 5-10 knots.

KBOS Terminal... High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Wednesday/...

Sunday Night: VFR.

Monday: VFR. Breezy.

Monday Night through Wednesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Saturday Night...High confidence.

SCAs remain in effect through 18z this afternoon given NW winds
gusting to 30 kt through tonight and seas to 5 ft into this
morning for the outer waters. While winds gradually diminish
through the day seas will generally be between 4-5 feet for the
outer waters. Heading into this evening and overnight, winds
and seas diminish; winds generally fall to 10 kt or less and
seas decrease to around 2-3 ft. Tranquil conditions on Sunday
with winds falling to 10-15 kt and 2-3 ft seas.

Outlook /Sunday Night through Wednesday/...

Sunday Night: Winds less than 25 kt.

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

Monday Night through Wednesday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for
     ANZ230>237-251-255-256.
     Small Craft Advisory until 2 PM EDT this afternoon for ANZ250-
     254.

&&

$$

DISCUSSION...BW/FT
AVIATION...Frank
MARINE...BW/FT