496
FXUS61 KBOX 041834
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
234 PM EDT Sat Oct 4 2025

.SYNOPSIS...
A ridge of high pressure in control of our weather will continue to
bring dry and unseasonably warm afternoon temperatures through
Tuesday. A cold front moves through Southern New England Tuesday
night into Wednesday, bringing rain and much cooler/drier
weather for Thursday and Friday.

&&

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

* Clear tonight...Lows mainly in the upper 40s and 50s
* Patchy ground fog in the typically prone locations late

Details...

An upper level ridge of high pressure will result in a dry/tranquil
night with above normal temperatures. Light winds will allow for
decent radiational cooling...so overnight low temps will range from
the upper 40s in the normally coolest spots to generally 50s
elsewhere. Meanwhile...the Urban Heat Island of Boston will be the
mild spot only drop into the lower 60s.

We probably will see some patchy ground fog late in the typically
prone low-lying locations...but not expecting anything
widespread.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Key Messages...

* Sunny & unseasonably warm Sunday with highs mainly 80-85 except
  middle to upper 70s along parts of the immediate coast

* Mostly clear Sunday night with lows mainly in the upper 40s & 50s

Details...

Sunday...

Upper level ridging in place will result in well above normal height
fields and another unseasonably warm day on Sunday. 850T near
+14C/+15C along with sunshine should push high temps into the 80-85
in most locations away from the immediate coast. Weak gradient will
result in sea breeze development along portions of the very
immediate coast and hold highs in the middle to upper 70s in those
locations. Regardless...another beautiful day is on tap for all of
southern New England with light winds and well above normal temps.

Sunday night...

A ridge of high pressure to our south will continue our tranquil/dry
weather with above normal temperatures. Low temps Sunday night
should range from the upper 40s in the normally coolest outlying
locations to generally the 50s elsewhere. The Urban Heat Island of
Boston will again be the mild spot with low temps only dropping into
the lower 60s.

Another round of patchy ground fog is expected late in the typically
prone low-lying locations.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

Key Messages:

 * Warm weather continues through Tuesday

 * A strong cold front will bring a quick return to fall
   temperatures starting Wednesday

 * Expecting rain and gusty winds to be accompanied by the cold
   front, but guidance remains uncertain on total QPF.

Unseasonably warm conditions continue into the start of the
workweek, with high temperatures reaching the upper 70s to low 80s
on Monday and Tuesday.  Bumped dewpoints down across the interior on
Monday, as Dry air aloft and good mixing will make it difficult for
dewpoints to exceed the low 50s away from the coasts.  There could
be some fire weather concerns on Monday as min RH values fall to
near 30% with southerly gusts at 10-20mph. Better moisture begins to
work in on Tuesday, allowing dewpoints to rise into the mid-to-upper
50s.

A strong cold front, supported by an upper-level shortwave, moves
through on Wednesday, bringing a swift end to the summer-like
temperatures.  Highs on Wednesday are expected to range in the 60s,
then drop to the upper 50s by Thursday.  Expecting gusty winds with
the passage of the cold front, with gusts of 20-30mph inland, and 30-
40mph near the coasts.  While at least some rain is likely on
Wednesday, the total amount of QPF remains uncertain.  The GFS
develops a surface low over the Ohio River Valley and tracks it over
SNE, bringing upwards of 1-2 inches of rain.  The Euro is not quite
as robust, with numerous showers accompanied by the cold front and
less than 1 inch of QPF.  ensembles seems to favor lower-end QPF
solutions, as the chance for 1 on GEFS and ENS is less than 20%.
Drying out quickly on Thursday with Canadian high pressure building
in. Remaining breezy on Thursday with northerly winds gusting 15-
20mph.

High pressure most likely remains in control on Friday, but the Euro
tracks a coastal low offshore, which could bring some increased
clouds.  Winds shift to the south, allowing high temperatures to
warm into the low to mid-60s.


&&

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

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

18z TAF Update...

This afternoon through Sunday night...High confidence.

VFR conditions continue through Sunday night outside of localized
very late night/early morning patchy ground fog in the typically
prone locations. Winds will be calm to light under 10 knots with
some localized diurnal sea breezes across portions of the immediate
coast.

KBOS Terminal...High confidence in TAF. Another round of sea breezes
expected for late Sunday morning into the afternoon.

KBDL Terminal...High confidence in TAF.

Outlook /Monday through Thursday/...

Monday: VFR. Breezy.

Monday Night: VFR.

Tuesday: VFR. Breezy.

Tuesday Night: Mainly VFR, with areas MVFR possible. Breezy.
SHRA likely.

Wednesday: Mainly VFR, with areas MVFR possible. Breezy. SHRA
likely, slight chance TSRA.

Wednesday Night: VFR. Windy with local gusts up to 30 kt.
Slight chance SHRA.

Thursday: VFR. Windy with local gusts up to 30 kt.

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight through Sunday night...High confidence.

A ridge of high pressure anchored to our south will continue to
result in relatively light winds and flat seas through Sunday night.
No marine headlines will be needed. We will have to watch for some
fog developing over the southern waters...mainly late Sunday
night.

Outlook /Monday through Thursday/...

Monday through Monday Night: Winds less than 25 kt.

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft.

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Areas of seas approaching 5 ft. Chance
of rain showers.

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of seas approaching 5 ft. Rain showers
likely, slight chance of thunderstorms. Local visibility 1 to
3 nm.

Wednesday Night: Strong winds with gusts up to 30 kt. Seas up
to 5 ft. Chance of rain showers.

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas up to 5 ft.

&&

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

&&

$$

SYNOPSIS...Frank/KP
NEAR TERM...Frank
SHORT TERM...Frank
LONG TERM...KP
AVIATION...Frank/KP
MARINE...Frank/KP