106
FXUS61 KBOX 101752
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
152 PM EDT Sat Oct 10 2026

.WHAT HAS CHANGED...
No significant changes. Potential for rain to last a bit longer
Monday morning, especially south coast.

&&

.KEY MESSAGES...

- Cool start Saturday followed by a nice day with a mix of clouds and
 sun.

- Rain arrives Sunday, likely exiting by Monday morning but there
 remains uncertainty on how quickly rain clears.

- Quick round of rain around Tuesday/Tuesday night, then dry
 weather returns Wed-Thu

&&

.DISCUSSION...
KEY MESSAGE 1...Cool start Saturday followed by a nice day with a
mix of clouds and sun.

Off too a cool start, especially where winds have become calm
allowing for better radiational cooling; many locations have dropped
into the low 40s while the warmer urban centers remain in the mid to
upper 50s. It will be a gradual warm-up with sunrise as high
pressure eventually becomes centered overhead providing a pleasant
Fall day. Mostly sunny skies will be filtered by high cirrus
streaming north ahead of an approaching weather system. Expect highs
to reach into the mid 60s. Trended lows toward MOS guidance a bit
Saturday night as winds will be calm, though high clouds will limit
radiational cooling if they`re widespread enough.

KEY MESSAGE 2...Rain arrives Sunday, likely exiting by Monday
morning but there remains uncertainty on how quickly rain clears.

The main focus for the holiday weekend weather-wise is generally the
24 hour period from 12pm Sunday to 12pm Monday. This, as a surge of
moisture makes its way north, the remnants of Hurricane Isaias.
After lifting north up the MS Valley it will be pulled east by a
northern stream trough and move over Southern New England,
strengthening as it exits the Mid-Atlantic coast and passes near the
40/70 benchmark. This plume of anomalous moisture (PWATs approaching
2 inches are 2-3 SD above normal) will interact with good dynamics
to squeeze out a good 0.5 (north) to 1 (south) inches of rain in
this time period. Some locations could see closer to 1.5" mainly
along the south coast where the core of a 40-50kt LLJ will move
overhead. Could also see a maxima on the slopes of the
Berkshires/Worcester Hills where orographics could help depending on
the exact track of the low. Ensemble guidance continues to suggest
low probabilities of 1+" rainfall totals outside of the south coast
where probabilities are in the 40-50% range. The short duration and
manageable totals do not suggest that we`d be concerned with flood
threat. The greatest uncertainty continue to be exactly when Sunday
afternoon the rain arrives and how quickly it exits Monday. Of late,
odds are increasing slightly that showers could linger Monday
morning, drying by the afternoon. We`ll know more as we get into the
hi-resolution guidance over the next 24 hours. Fortunately, the bulk
of the aforementioned LLJ should be kept aloft by inverted
atmospheric profiles so we are not expecting damaging winds with
this system at this time. Small Craft Advisories will likely be
needed on the waters for gusts 25-30 kts.

KEY MESSAGE 3...Quick round of rain around Tuesday/Tuesday night,
then dry weather returns Wed-Thu

It`s but a brief respite from the rain on Monday as the mid level
ridging following Sunday night`s system will quickly be ushered out
as another shortwave swings through on Tuesday with PWATs quickly
back up to 1.75". As the surface low passes near or just to our
north generating a 35-45 kt 850mb LLJ resulting in breezy and wet
weather around Tuesday or Tuesday night. High pressure returns
Wednesday into Thursday ushering in a quiet and seasonable stretch.

&&

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

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

18Z update...

Today and Tonight: High confidence.

VFR. NW/NNW winds for much of day at 6-10 kts. Winds shift to
the NE, then around to the ESE/SE after 20Z. Winds turn more
S/SSW into Sunday after 03Z while winds stay SE for the
Cape/Island terminals less than 8 kts.

Sunday and Sunday Night: High confidence.

VFR. S/SE winds 5-10 kts with RA arriving from west to east
generally between 16Z-20Z. MVFR ceilings and -SHRA overspread
the region from west to east 21z-24z.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Thursday/...

Columbus Day: Mainly VFR, with local IFR possible. Breezy.

Monday Night: VFR.

Tuesday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA, slight chance TSRA.

Tuesday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SHRA, slight chance TSRA.

Wednesday: VFR. Breezy. Slight chance SHRA.

Wednesday Night through Thursday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Sunday Night: High confidence.

Winds 10-15 kt today become light northeasterly late this
evening into tonight as high pressure approaches. Seas 3 ft or
less all waters. Sunday winds increase again ahead of
approaching low pressure, S/SW 10-15 kts gusting 15-20 kts. Seas
begin to build late Sunday evening into the night. SCA`s will
likely be issued with future shifts.

Outlook /Sunday Night through Thursday/...

Columbus Day: Winds less than 25 kt. Rough seas up to 9 ft.
Chance of rain showers.

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

Tuesday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain
showers.

Tuesday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Rain showers likely, slight
chance of thunderstorms.

Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 25 kt. Areas of rough seas. Chance of rain showers.

Wednesday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain
showers.

Thursday: Winds less than 25 kt. Rough seas up to 9 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

DISCUSSION...BW
AVIATION...McMinn
MARINE...BW