723
FXUS61 KBOX 071833
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
233 PM EDT Tue Oct 7 2025

.SYNOPSIS...
Cold front approaches the region tonight into Wednesday, bringing
much needed rainfall. Much cooler temperatures follow Thursday and
Friday with dry weather as well. Monitoring a possible coastal storm
early next week, but it remains uncertain if it will track far
enough north to bring us some rain and gusty winds.


&&

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

* Mild and dry this afternoon, rain arrives after midnight as a cold
  front moves into the region. Periods of light to moderate rain
  expected into the Wednesday morning commute.

Morning stratus gave way to sunshine, albeit short-lived, as mid and
high clouds arrive ahead of an approaching cold front and mid-level
trough. This afternoon is breezy and mild by early October standards
with afternoon highs reaching between the upper-70s and lower-80s. A
strengthening pressure gradient from the departing high pressure and
the incoming cold front provides breezy southwest to south-southwest
gusts up to 25mph.

The aforementioned cold front arrives late-tonight and exits east of
the coastal waters Wednesday, in fact, first-half of tonight remains
dry. Rain overspreads from west to east, entering western areas of
southern New England roughly on either side of midnight and getting
to the Boston to Providence corridor by 5 AM to 7 AM. Cold front is
interacting with sufficient moisture, PWATs are roughly ~1.6" which
is two standard deviations above normal. Cannot rule out a rumble or
two of thunder either with limited instability, leading to pockets
of heavier rain. Much needed rainfall amounts between 0.5" and 1.0"
for most of the region, though an area of higher amounts of 1.0" to
2.0" cannot be ruled out within areas of convection. HREF showed a
strip of these higher totals from southeast CT, southern RI, and
southeast MA with totals up to 1.5". While not out of the question
but still a low probability, is the chance of 2+ inches across RI
and southeast MA, based off the HREF ensemble LPMM.

Don`t anticipate any flash flooding, although common poor drainage
areas could see large puddles, especially leaf litter starting to
collect with fall underway. Not ideal for the morning commute, do
take your time heading out the door.

With the added cloud cover tonight and southerly flow it will remain
mild with lows in the upper-50s and lower-60s.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
Key Messages:

* Cold front exits with showers ending by late morning west and
  early afternoon east. Clearing overnight with chilly temperatures.

The mid-level trough pushes the surface cold front out to sea and
will have improving conditions starting late morning across CT River
Valley. These conditions gradually improve to the east, reaching the
I-95 corridor by early afternoon, and finally clearing the Cape and
Islands midafternoon. Temperatures are noticeably cooler behind the
front, in fact, many daytime highs likely occur during the morning
hours. Early afternoon temperatures are only in the low-60s and with
a breezy north-northwest wind, Brrr!

Overnight, a 1035mb high build across the northern Great Lakes with
clearing skies and north-northwesterly flow. Will be chilly, lows
fall into the low-40s and upper-30s. Would not be surprised if a few
of our high elevation communities in northwestern MA (AOA 1,500 ft)
dip down to the freezing mark.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Key Messages...

* Dry/much cooler Thu/Fri...highs in the middle 50s to the lower
  60s...lows Thu night in the 20s/30s with frost/freeze conditions

* Remaining dry Sat with highs moderating into the middle-upper 60s

* Potential for a Hybrid coastal storm to bring some rain/gusty
  winds early next week...but may remain south keeping us dry

Details...

Thursday and Friday...

A large 1035 mb high pressure system builds in from the Great Lakes
Thu into Fri. This will bring in much cooler/below normal
temperatures to the region. Despite plenty of sunshine Thu...850T
dropping to between -2C and -4C will hold Thu high temps to between
55 and 60 in most locations!. NNW winds will gust to between 20 and
25 mph...so a taste of fall is on tap for the region.

High pressure builds overhead Thu night setting the stage for an
excellent night of radiational cooling. Given the dry/cool airmass
overhead...thinking overnight low temps will mainly be in the 20s
and 30s. This will result in our first fairly widespread
frost/freeze conditions across southern New England. Plenty of
sunshine follows for Fri and as mid level temps moderate a
tad...expect highs to recover into the lower 60s. Much lighter winds
on Fri compared to Thu...so it will feel milder by Fri afternoon.

Saturday...

Upper trough shifts east of the region along with high pressure at
the surface...but it will remain dry. This allows a return flow of
milder air to work in from the southwest. Highs should recover Sat
into the middle to upper 60s.

Sunday through Tuesday...

The forecast remains quite uncertain early next week. We will be
watching a potential Hybrid coastal storm off the mid-
Atlantic/southeast coast. There is considerable spread on the models
and their ensembles on whether or not this system will get far
enough north to bring some rain/gusty sometime Sunday through
Tuesday or stays south and we remain dry. We still need a few more
days until we have a better idea. For what its worth...the one thing
we noticed was that the EPS tended to be more suppressed compared to
the EPS AI version...which brings the rain significantly further
north into our region. We should also mention that if the storm does
come far enough north...there will be a minor coastal flooding risk
as we will just be coming off King Tides.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

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

18z Update...

Today...High confidence.

VFR with SW wind gusts of 20-25 kts.

Tonight...Low confidence on fog development. Moderate
confidence on rain timing.

VFR becoming MVFR/IFR under RA from northwest to southeast very
late tonight through daybreak Wed. Expecting around 35kts of
wind shear to develop after 00z, with guidance indicating 925mb
winds of 40-45 kts. With a surge of moist air ahead of the
front, there`s a chance some fog could develop before the RA
begins, but low confidence on this.

Wednesday...Moderate confidence.

MVFR/IFR under RA. VFR developing from NW to SE during the
afternoon, reaching the coast towards evening.

KBOS Terminal...Low confidence on fog development. Moderate
confidence on rest of TAF.

KBDL Terminal...Moderate confidence on rain timing.

Outlook /Thursday through Saturday/...

Wednesday Night: VFR. Breezy.

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

Thursday Night: VFR. Breezy. Areas frost.

Friday through Saturday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Wednesday Night... Moderate Confidence.

Southwest wind and gusts are increasing ahead of an approaching cold
front, which will swing across the waters on Wednesday. Gusts of 20
to 30 knots are expected and seas 3 to 5 feet.

Have expanded the Small Craft Advisory to all waters, with the
exception of Narragansett Bay and Boston Harbor. Light to moderate
rain is expected Wednesday morning with lower visibilities.

Improving conditions Wednesday night with clearing skies, but
breezy north-northwest continue, albeit, below advisory criteria.

Outlook /Thursday through Saturday/...

Wednesday Night: Strong winds with local gusts up to 30 kt.
Seas up to 5 ft.

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Local rough seas.

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

Friday through Saturday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 5 PM EDT Thursday for ANZ231>235.
     Small Craft Advisory from 8 AM Wednesday to 5 PM EDT Thursday
     for ANZ237-251.
     Small Craft Advisory until 5 PM EDT Thursday for ANZ250.
     Small Craft Advisory from 1 AM Wednesday to 5 PM EDT Thursday
     for ANZ254>256.

&&

$$

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