430
FXUS61 KBOX 061114
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
714 AM EDT Mon Oct 6 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 much needed rainfall. Much cooler
temperatures follow Thursday and Friday with dry weather as
well. Monitoring possible coastal storminess for next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
330 AM Update:

Key Messages:

* Sunny, unseasonably warm again with highs in the low to mid
  80s away from the southern coast.

* Early-day low clouds/fog and south breezes may keep the south
  coast closer to the mid 70s for high temps.

Details:

Still under sfc high pressure which is anchored to our south, with a
more prounounced mid/upper ridge across the eastern seaboard. This
is at least providing clear skies for areas north and west of I-95.
Meanwhile, shallow moisture advection (dewpoints in the upper 50s to
lower/mid 60s) on light SW flow in conjunction with nighttime
cooling has allowed for a greater extent of patchy fog and low
clouds into portions of CT, western/southwest RI, southeast MA and
adjacent waters. With a few more hours of cooling to go, we probably
will see this layer of fog and low clouds fill in some, but should
be limited to no further north than the CT-MA-RI border area. It is
a pretty mild start to Monday, with temps in the mid 50s to low 60s.

Even with this morning`s low clouds and fog in portions of CT-RI-SE
MA, we still expect above normal temperatures to again develop. SW
winds will be gradually increasing through the day to around 10 mph
by the afternoon in most areas. Highs away from the southern coast
should again reach into the lower to mid 80s. Southerly flow off the
water should keep the south coast cooler than inland, but even so,
it`s a little less clear how warm areas near the south coast, Cape
and Islands may get. The fog and low clouds from early this morning
may take some time to dissipate (late morning?), and that moisture
may linger over the waters. I offered some partial cloudiness and
temps mainly in the mid 70s as something of a middle-ground; but if
low clouds stick around, then temps could be quite a bit cooler
closer to what NAM-based temps show.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
330 AM Update:

Key Messages:

* Mild night with low clouds/fog returning northward, to go
  along with SW breezes.

* Early clouds give way to a period of mostly clear skies, but
  clouds increase late in the day. Still above normal temps but
  not as anomalously warm as prior days. SW breezes around 20
  mph.

Details:

Tonight:

Not much change on the large-scale, with high pressure still to our
south. However SWly pressure gradient continues and tends to
strengthen somewhat overnight, with speeds around 10 mph. That also
seems likely to advect continued shallow moisture northward; low
clouds and mist/fog may begin to expand northward from the southern
waters by late in the evening and could make it quite a bit further
inland than tonight, perhaps as far north as the Mass Pike. Another
rather mild night with lows in the upper 50s to the mid 60s.

Tuesday:

With low clouds and areas of mist/fog making it further northward
for Monday night, similar forecast concerns exist regarding how warm
temperatures may get; but thinking fog/low clouds should dissipate
inland during the morning, but could linger for a while along the
southern coast. SW winds will continue to pick up through the day,
with 20-25 mph breezes developing. A greater amt of cloud cover then
begins to arrive toward Tue afternoon as a cold front approaches
western New England. Factoring in a bit more cloud cover, both in
the morning and late in the day, suggests highs will be slightly
cooler than today, in the 70s to the low 80s, and around the lower
to mid 70s for the south coast.

&&

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

* Overcast with periods of rain and lower-risk for thunder Tue
  night thru Wed.

* Much cooler, blustery and dry Thu/Fri, with possible chilly/frosty
  night Thurs night.

* Monitoring possible slow-moving coastal storminess moving up
  from the mid-Atlantic this weekend.

Details:

Tuesday Night and Wednesday:

Forecast models are starting to show better agreement on a cold
front moving through Southern New England Tue night and into much of
Wed. This will bring a much needed rainfall to our area, which has
seen rainfall deficits deepen further over the last week. Pretty
strong cold front interacts with a ribbon of enhanced moisture to
around 1.3-1.5" PWATs suggests a period of steady light to moderate
rains; a rumble of thunder is possible with some weak elevated
instability shown in forecast models but would probably serve to
enhance rain rates than produce strong thunderstorms. Rain amounts
are still a little uncertain but probs of 24-hr rain accumulations
over a half inch or more continue to increase. With overcast and
southwest breezes pre-frontal, warmest night probably is Tue night
in the lower to mid 60s; but highs on Wed might not climb very much
at all, in the mid 60s to near 70 before onset of strong cold
advection and increasing northwest breezes.

Wednesday Night through Friday:

Strong high pressure starts to build in Wed night, to go along with
a rather cool airmass (925 mb temps drop to around +2 to +4C!).
Rather breezy and cool Wed night as early clouds decrease, with
N/NNE winds around 10-15 mph, with gusts 20-25 mph over the Cape and
Islands. The winds should keep low temps from really bottoming out,
which are in the lower to mid 40s, but it will feel quite a bit
cooler than that when factoring in the northerly winds.

High and dry for Thurs and Fri, with slowly-decreasing northerly
winds for Thurs. Full sun will be offset by the cool temps aloft,
which keep highs Thurs in the mid 50s to around 60. High pressure
then settles over the region Thurs night, and we should really
radiate quite well. Could have the first night with frosty temps in
the 30s in many areas (mid 40s for the cities). Highs Fri in the
lower to mid 60s.

Finally...will mention that the king tide will be taking place this
week, where the highest high tides occur. These high tides are
highest during the daytime hours Thurs and Fri. Thinking it`s
unlikely we`ll see any coastal/tidal flooding problems given
that winds are northerly. The areas we may have to watch are
along Cape Cod Bay and at Nantucket on Thurs, but it would take
stronger northerly winds before some minor overwash could occur.
Latest probabilistic guidance from Stevens Institute shows a
storm tide just under 5 ft at Nantucket Thurs aftn as a worst-
case.

Next Weekend:

High pressure initially is in control, but the 00z deterministic
guidance, with some support in their ensembles shows a slow-moving
coastal low pressure beginning to affect the mid-Atlantic and
southern New England coasts later Sat and Sun. There is time to
assess this, but if this low pressure does indeed materialize and
approaches from the south...we could have a few days of overcast,
cooler temperatures, enhanced east breezes and some rains. We`d also
have to watch for possible coastal/tidal flooding too, with
astro tides still being elevated as we start to come out of the
king tide. Something to monitor as we move through the workweek.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...

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

12z TAF Update...

Today: High confidence, though moderate on how soon fog/low
clouds dissipate.

Patchy MVFR-IFR fog and stratus along the South Coast, Island,
and CT River Valley terminals. Generally improving flight
categories to VFR in most if not all areas 12-15z; fog/low
clouds along the south coast from overnight could be slow to
dissipate until closer to late morning. SW winds increase to
around 10 kt by this aftn.

Tonight: Moderate confidence.

VFR early, but MVFR-LIFR fog/low clouds stand to expand
northward again tonight, and could make it as far north as ORH,
BED and BOS after 08z. Better confidence on sub-VFR for the
south coast before 06z. SW winds around 5-10 kt.

Tuesday: High confidence, but moderate on how soon fog/low
clouds dissipate from Monday evening.

Similar to tonight, generally improving flight categories as low
clouds/fog begin to disperse, but it may be slow to dissipate
again near the south coast. SW winds increase to around 10-15 kt
with gusts 20-25 kt.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

VFR. Light southerly winds

Outlook /Tuesday Night through Friday/...

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

Wednesday: MVFR/IFR conditions possible. Breezy. SHRA.

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

Thursday: VFR. Breezy.

Thursday Night through Friday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

SW winds increase to around 10-15 kt with gusts to 20 kt today
and into tonight. SW winds on Tue may become close to SCA
criterion, but probably fall just short of SCA levels. Seas 4
ft or less on all waters through today, then start to increase
some to around 4-6 ft by Tue aftn. Nighttime fog and low clouds
can be expected to reduce visby thru this morning and again
tonight.

Outlook /Tuesday Night through Friday/...

Tuesday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft. Chance of
rain showers.

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

Wednesday Night: Strong winds with gusts up to 35 kt. Seas up
to 5 ft. Slight chance of rain showers.

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

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

Friday: Winds less than 25 kt.

&&

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

&&

$$

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