412
FXUS61 KBOX 111709
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
109 PM EDT Sat Oct 11 2025

.SYNOPSIS...
High pressure maintains drier and colder conditions today. A
coastal storm brings rain and gusty winds Sunday into Monday
night, along with the minor coastal flooding and erosion.
Unsettled weather will be possible through much of next week
towards the eastern half of southern New England.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages...

* Dry with near normal temperatures

High pressure continues to move offshore today, resulting in an
increasing E to SE flow. Clouds this morning develop a few
breaks into this afternoon. Overall, a typical quiet Fall day.

&&

.SHORT TERM /SUNDAY/...
Key Messages...

* Coastal storm arrives Sunday afternoon

Not much change to the expected pattern within the latest
guidance suite. Still some uncertainty with timing and how far
north the main impacts will get. Do have high confidence in a
measurable rainfall across our region, but will need a little
more time to work out the details on how much rainfall we could
actually see. Favored the slower timing for rainfall as we will
have a lot of dry air to overcome.

Have the greatest confidence in widely ranging rainfall totals
through Sunday. By evening, areas towards northwest MA may see
very little rainfall, while areas towards Nantucket could be
approaching 1 inch of rainfall. Winds will also begin increasing
Sunday afternoon with a similar pattern of the highest winds
towards Nantucket.

&&

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

* Coastal storm effects linger through Tuesday

* Cooler air may move in towards the end of next week following
  this storm with some lingering showers towards the east coast

A coastal low will continue to make its way up the eastern US
coastline. It still appears like this will be a prolonged
rainfall event, mainly from Sunday night into Tuesday morning.
When all is done some time Tuesday, rainfall could range from
around one inch towards northwest MA, to as much as 3-4 inches
towards southeast MA. It`s how sharp the rainfall gradient will
be that remains a question. We really can use this rainfall.
It`s duration allays concerns about flash flooding, but we will
need to watch out for poor-drainage flooding, especially where
storm drains may be blocked by leaves or debris.

Winds will pick up Sunday night as this storm approaches and
the pressure gradient between it and a strong Canadian high
pressure tightens. Gusts close to 50 MPH will be possible over
the Islands, with the Cape seeing gusts around 45 MPH; the rest
of southern New England can expect gusts to 30-35 MPH. With
higher confidence in these elevated winds over the Cape and
Islands, continued a High Wind Watch for the islands and a Wind
Advisory for Cape Cod. With the combination of higher seas and
winds, some beach erosion and minor coastal flooding cannot be
ruled out.

Once this storm shifts out to sea, we may start to see even
cooler conditions with rain chances starting to decrease. Some
guidance is indicating it expanding a bit, and as surface high
pressure behind an upper level trough cutting down from Canada
moves in towards Friday, the gradient between these systems may
end up elevating winds slightly once more. NW winds will help
advect in cooler air as well, with 925 mb temperatures sinking
to 5C and lower. This would favor highs in the mid 50s to end
next week.

&&

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

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

Through Tonight...High confidence.

VFR cigs. Ceilings lower into the lower-end VFR range early Sun
morning. Winds become light and variable during the late
morning/early afternoon, before becoming E-NE around 10 kt by
early Sun morning.

Sunday...High confidence in trends. Moderate confidence in
timing.

MVFR/IFR developing by afternoon, especially towards the south
coast. Rainfall developing from south to north, especially
during the afternoon hours.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Thursday/...

Sunday Night: Mainly MVFR, with areas IFR possible. Strong
winds with gusts up to 45 kt. RA.

Columbus Day: Mainly IFR, with areas MVFR possible. Strong
winds with gusts up to 40 kt. RA.

Monday Night: Mainly MVFR, with areas IFR possible. Windy with
gusts up to 35 kt. RA, isolated TSRA.

Tuesday: Mainly VFR, with local IFR possible. Windy with gusts
up to 35 kt. Chance RA.

Tuesday Night: VFR. Breezy. Slight chance RA.

Wednesday: VFR. Breezy. Slight chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today...High confidence.

Relatively light winds and seas during this time with high
pressure over the waters. Good visibility.

Tonight...High confidence.

E/NE wind gusts increase to 20-30 kts by sunrise over the
southern waters, with seas increasing to 5-8 ft. A Storm Watch
remains posted to address potential for stronger winds over the
waters late Sunday and Monday.

Outlook /Sunday Night through Thursday/...

Sunday Night: Storm force winds possible with gusts up to
45 kt. Rough seas up to 18 ft. Rain.

Columbus Day: Storm force winds possible with gusts up to
45 kt. Rough seas up to 18 ft. Rain. Local visibility 1 to
3 nm.

Monday Night: Strong winds with gusts up to 40 kt. Rough seas
up to 17 ft. Rain, slight chance of thunderstorms.

Tuesday: Strong winds with gusts up to 40 kt. Rough seas up to
13 ft. Rain.

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Rough seas up to 12 ft. Chance of rain,
slight chance of rain showers.

Wednesday: Winds less than 25 kt. Rough seas up to 10 ft.
Chance of rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Coastal Flood Advisory from 2 PM to 6 PM EDT Sunday for MAZ007-
     015-016-019-022>024.
     Wind Advisory from 5 PM Sunday to 8 PM EDT Monday for MAZ022.
     High Wind Watch Sunday afternoon for MAZ023-024.
     High Wind Warning from 5 PM Sunday to 2 PM EDT Monday for
     MAZ023-024.
RI...High Wind Watch Sunday afternoon for RIZ008.
     High Wind Warning from 5 PM Sunday to 2 PM EDT Monday for
     RIZ008.
     Coastal Flood Advisory from 11 AM to 3 PM EDT Sunday for
     RIZ006>008.
MARINE...Gale Watch Sunday afternoon for ANZ230-236.
     Gale Warning from 5 PM Sunday to 8 PM EDT Monday for ANZ230-
     231-233-234-250-251-254.
     Storm Watch Sunday afternoon for ANZ231>235-237-250-251-
     254>256.
     Storm Warning from 5 PM Sunday to 8 AM EDT Monday for ANZ232-
     235-237-255-256.
     Gale Warning from 5 PM Sunday to 2 PM EDT Monday for ANZ236.

&&

$$

SYNOPSIS...KJC/Loconto
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...Loconto
AVIATION...McMinn/Nocera
MARINE...KJC/Loconto