Area Forecast Discussion
Issued by NWS Boston, MA

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251
FXUS61 KBOX 121405
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1005 AM EDT Mon Oct 12 2026

.WHAT HAS CHANGED...
Tweaked sky cover and temperatures for today this morning.
Increased rain chances and winds for the late week/weekend storm
as confidence increases.

&&

.KEY MESSAGES...

- A drier, warmer, and increasingly sunny Monday. Low clouds and
  rain showers return Tuesday/Tuesday night with a rumble of
  thunder possible.

- Drying out Wednesday, and especially Thursday, under high
  pressure.

- Next, stronger storm system arrives Friday into Saturday.

&&

.DISCUSSION...
KEY MESSAGE 1...A drier, warmer, and increasingly sunny Monday.
Low clouds and rain showers return Tuesday/Tuesday night with
a rumble of thunder possible.

Latest satellite data showed some breaks in the clouds from
southeast NH, across north central MA, into portions of
northern CT. More stubborn lower clouds remained across
southeast MA and much of RI. Tweaked the timing of this clearing
for today. This timing will be crucial for temperatures as
well. Full sunshine should be able to boost temperatures towards
the upper 60s to lower 70s with 850mb temperatures of +10-15C.
The longer the clouds linger, the more likely temperatures stay
in the 60s. Tweaked afternoon temperatures down slightly this
morning, but they should still be a least 10 degrees higher
across interior southern New England than Sunday.

Things change tonight as a low center over the Great Lakes
approaches while high pressure sits over Nova Scotia. This
initially turns surface flow out of the northeast advecting
cooler, saturated air onshore making for low clouds with patchy
drizzle to start Tuesday. This brings highs back into the 60s.
The warm front lifts north Tuesday afternoon bringing scattered
rain showers which continue until the cold front drops through
sometime Wednesday. SNE will be socked in with clouds all of
Tuesday and Tuesday night as moisture remains trapped under a
strong inversion. Could even see some rumbles of thunder given
some weak elevated instability above that inversion. Elevated
dewpoints will also lead to mild lows, in the upper 50s and
lower 60s.

KEY MESSAGE 2...Drying out Wednesday, and especially Thursday,
under high pressure.

Wednesday things begin to dry out behind the cold front and the
inversion mixes out allowing for a mix of clouds and sun.
However, a stronger reinforcing cold front brings a much cooler
and drier airmass for Thursday as high pressure arrives. 925mb
temps drop to near 6C leading to highs only in the low 60s under
mostly sunny skies.

KEY MESSAGE 3...Next, stronger storm system arrives Friday into
Saturday.

Our next storm, this one likely stronger than the mid week
system, originates out west Thursday. A low forms in the lee of
the Rockies, phasing with another low over the Great Lakes as it
is swept east by a northern stream trough. It then strengthens
as it moves over or near New England Friday into Saturday. This
pulls a lot of moisture into the region and with good dynamics
including potential for a strong 45-55kt LLJ and favorable
placement beneath the RRQ of a 160kt upper jet, we should see a
windy and very rainy Friday-Saturday. Timing and other details
are uncertain at this time, but confidence in at least a
decently strong weather system is increasing.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...

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

Today: High confidence in trends, but moderate on timing
improvement.

IFR ceilings continue across RI and southeast MA. VFR
Anticipating slow improvement to IFR ceilings toward MVFR by
14-16z from northwest to southeast, then trending SCT VFR by
17-19z (periodic MVFR ceilings thru 19z). North winds around
5-10 kt, decreasing in speed to around 5 kt by afternoon.

Tonight: High confidence in trends but moderate on timing
backdoor cold front.

VFR early tonight; then a backdoor cold front progresses
southward from NH/ME. Timing approximately 02-04z for BED, and
around 04-07z for the remaining TAFs. This will bring lowering
ceilings again into the MVFR-IFR range, light -RA and winds
turning NE around 5-10 kt, strongest near the coast.

Tuesday: Moderate confidence.

MVFR-IFR ceilings, with lighter rains or drizzle. Possible
MVFR-VFR optimism by mid to late afternoon. NE/E winds around
5-10 kt, turning SE/S by afternoon and increasing to around 10
kt.

KBOS Terminal...High confidence in trends, moderate
confidence in timing. Slow improvement from IFR by 14-15z, then
MVFR thru 17z before trending MVFR/VFR. Backdoor cold front
brings NE winds late tonight (after 04z Tue).

KBDL Terminal...High confidence in TAF.

Outlook /Tuesday Night through Friday/...

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

Wednesday through Thursday: VFR. Breezy.

Thursday Night: VFR. Chance SHRA.

Friday: VFR. Windy with local gusts up to 30 kt. SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Monday: High confidence.

The remnants of Hurricane Isaias are currently working their way
across the southern waters. Seas 5 to 10 ft and wind gusts
20-30 knots. SCAs are in effect for the southern waters, 15-20
kts with gusts to 25kt possible, especially on the southern
outer waters. Seas 6-9 ft on southern waters, 3-6 ft on the
eastern waters.

Monday night: High confidence.

NE winds 10-15 kts with gusts 20-25 kts on the eastern waters.
Seas 3-5 ft.

Tuesday: High confidence.

SE winds 10-15 kts with increasing gusts to 20 kts. Seas 3-5 ft.
RA over the eastern waters.

Outlook /Tuesday Night through Friday/...

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

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

Wednesday Night: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers.

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

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

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Local rough seas. Rain showers likely, slight
chance of thunderstorms.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for ANZ235-
     237.
     Small Craft Advisory from 8 PM this evening to 2 AM EDT
     Wednesday for ANZ250.
     Small Craft Advisory until 8 PM EDT Wednesday for ANZ254.
     Small Craft Advisory until 8 AM EDT Tuesday for ANZ255-256.

&&

$$

DISCUSSION...BW
AVIATION...Belk/Loconto/BW
MARINE...BW