ct discuss
Office: BOX
FXUS61 KBOX 090849
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
349 AM EST Sun Nov 9 2025
.SYNOPSIS...
Mostly cloudy today, with light rains breaking out this
afternoon as a warm front lifts through Southern New England.
Temperatures warm into the mid to upper 50s overnight with fog
and drizzle. A strong cold front moves through the area on
Monday, with mild temperatures to start but then sharply falling
through Monday afternoon. Breezy with below normal temperatures
on Tuesday. Slight improvements in temperatures Wednesday
before a reinforcing trough arrives later next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
330 AM Update:
Key Messages:
* Mostly cloudy but dry through about noontime.
* Warm front spreads light rain northward during the afternoon, with
steadier rains and a rumble or two of thunder possible late this
afternoon in southeast New England.
* Overcast, generally dreary tonight with mist/drizzle, and
slowly rising temps overnight.
* Daytime max temps in the lower to mid 50s, but warming temps
in mid to upper 50s overnight as warm airmass spreads in.
Details:
Aside from the immediate South Coast where skies were mostly clear,
most of Southern New England otherwise has been blanketed by mid-
level cloudiness from a mid-level warm front working its way
northeast from central NY/southern Adirondacks vicinity. Radar's
picking up on spotty rain showers in eastern NY to the Berkshires,
but this is really not much impact if the ground is even wettened at
all. Current temps were still pretty mild given the midlevel cloud
deck with temps in the 40s. At least thru sunrise, may have to watch
for patchy fog to develop near the south coast thru sunrise, where
better radiational cooling is taking place and modest southeast flow
allowing for a creep-up in dewpoints.
Large-scale picture is...in a word, complicated. Initial sfc
low is analyzed roughly near northern IN, which is expected to
pass well to our northwest. While it's not really evident yet in
sfc obs, we are expecting a weaker secondary low to take shape
near the VA Piedmont region this morning; and it's this
secondary low/related warm-frontal feature that we expect to
move NE through the mid- Atlantic and affect Southern New
England through today.
For today: the ongoing midlevel cloudiness should lift
northward into the mid-morning hours, allowing for a brief
period of sun/limited diurnal warming. But it won't be for very
long, as cloud cover starts to fill in again from SW to NE in
all areas late this morning as the warm front near the mid-
Atlantic states begins to approach our southern coast. Pretty
strong warm/moist advection accompanies this warm front, which
will spread light rains between about noon to 6 PM from south to
north. Modest burst of elevated instability which brushes
eastern RI and SE New England (e.g. most-unstable CAPEs around
100-300 J/kg) late this afternoon into early tonight, as
dewpoints rise into the low to mid 50s. Shown PoPs increasing
into the lower Likely range (55-60%) for light rain in all areas
by early this afternoon, but are in the Categorical range
(70-85%) for eastern and southeast New England where a low (15%
or less) risk for thunder exists accompanying that instability
burst. Northern CT into western MA/Berkshires have lesser PoPs
(55-60%) as they could get stuck between the primary cyclone
passing to the west and the warm frontal feature/secondary low
moving offshore. Rain amts could be as much as a half-inch in
southeast New England, but taper off to a quarter inch or less
inland. Daytime high temps today may not rise much further than
the mid 50s...but in some or even most areas, today's high
occurs by midnight as warm/moist advection ensues.
Moving into tonight: warm front lifts northward into northern
New England early tonight. We get into a moist southerly flow in
its wake, as 850 mb temps warm to around +5 to +10C. Model
soundings show a roughly 50 to 100 mb-thick layer of high RH
beneath a dryslot above 900 mb for the evening and overnight in
the moist warm-sector. Not expecting any showers tonight, but
this is a typical setup for quite a bit of stratus and drizzle,
with misty conditions as well. Temperatures and dewpoints stand
to rise in a non-diurnal fashion as well, thus early lows with
temps rising into the middle to even upper 50s. We'll have to
watch the timing of an approaching potent cold front into the
Berkshires, although seems more likely to move in on Monday.
&&
.SHORT TERM /MONDAY/...
330 AM Update:
Key Messages:
* Overcast but a mild start to Monday morning with temps in the
mid/upper 50s.
* Strong cold front moves through approximately 8-10 AM western
MA/CT, around noon for central MA, and around 1-3 PM for eastern
MA/RI. Brings a period of light to moderate passing rain showers.
* Sharply falling afternoon temps through the 40s behind the front.
Details:
Monday:
Amplified 500 mb pattern develops over eastern CONUS on Mon, as
an anomalously strong upper trough digs into the Ohio and
Tennessee Valleys and the mid-South. Once a cold front traverses
our area on Monday, it will usher in some of the coldest air of
the fall into Southern New England in the hours after its
passage.
The day starts off overcast and anomalously mild; in fact, many
locations in Southern New England end up being some 10+ degrees
warmer than the forecast highs in locations in several major
cities in the mid-South. A strong cold front will be working its
way through Southern New England Mon, the timing is low-
confidence. Some models such as the GFS have the front clearing
into the waters as early as late morning, while others have a
frontal passage offshore by late in the day. Best estimate on
the cold front's clearing is around 8-10 AM in the
Berkshires/CT Valley, close to noontime in central MA/eastern
CT, and early-mid afternoon for eastern MA and RI. Frontal
passage will be marked by limited clearing with a period of
light to moderate rains, but with crashing temps behind it.
Temps in interior New England fall through the 40s by Mon aftn
with some late- day readings around freezing in the Berkshires,
and temps will just be starting to fall into eastern MA. Think
there's just enough drier air post-frontal that we won't have to
contend with rain mixed with snowflakes in the Berkshires, but
it's pretty close.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Messages:
* Rain quickly comes to an end early Monday night
* Blustery with winter-like cold on Tuesday. Wind gusts to 30-40 mph
* Mostly dry and blustery at times Wed through Sat with below normal
temps.
Deep upper trough will move from the Great Lakes to the CWA Monday
night into Tuesday. Fast-moving surface low races northeast Mon
night. Mid-level dry slot quickly puts an end to any lingering
precipitation early Monday night. Leftover showers in the high
terrain end as a brief period of snow showers as the column rapidly
cools from top down, but elsewhere dry air should win out before it
gets cold enough for any snow. Much drier air moves in from the west
with dewpoints falling into the 20s by early Tuesday morning. Lows
Mon night will drop into the mid-upper 20s interior and lower 30s
coastal plain. A few elevated locations in the far interior may even
fall into the upper teens.
Cold and windy day on tap Tuesday with a lingering pressure gradient
and strong cold air advection behind departing low pressure. 850 mb
temps drop to near -10C which will result in highs ranging from mid-
upper 30s higher terrain to low 40s coastal plain. Soundings show a
deep and well mixed boundary layer with 925 mb winds increasing to
35-40kts Tue supporting westerly wind gusts to 30-40 mph in the
afternoon making it feel more like the 20s and 30s even in the
afternoon. It looks mainly dry as the column is quite dry with PWATs
less than 0.2" but can't rule out a few flurries or snow showers in
the higher terrain as cold pool aloft with -35C 500 mb temps move
into the region. And a few ocean effect showers are possible over
the Islands. Otherwise sunshine will mix with developing diurnal cu.
Core of the upper level trough moves out Tue night but broad trough
sets up across much of the Northeast through the end of the week as
a series of fast moving shortwaves reinforce the trough. The trough
then amplifies east of New Eng on Saturday. Moisture is quite
limited so expecting dry conditions most of the time with sunshine
and diurnal cu, but can't rule out a few brief showers at times Wed
through Fri, with low confidence on timing. Temps recover Wed-Thu
but remain below normal then another shot of colder air moves back
in for Fri-Sat. It will also be blustery at times from multiple
shortwave passages.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06Z TAF Update:
Tonight: High confidence.
VFR. Winds turn NW to NE under 10 kt through 04-06z. Few mid-
level decks may move through overnight.
Sunday: Moderate confidence.
VFR early AM, trending MVFR after 15z as showers arrive from
the south 17-21z. IFR with pockets of LIFR conditions possible
in evening. E winds 8-12 kts with some gusts around 18 kts
possible closer to 20 kts for Cape/Islands.
Sunday Night: Moderate Confidence.
MVFR. Models are trending toward more widespread IFR and LIFR ceilings
overnight although confidence is still moderate for extent of
LIFR. Winds E turning SE for the coastal terminals. Speeds 8-12
kts for eastern terminals and less than 10 kts for interior
terminals. Gusts around 20 kts for Cape/Islands early. Winds
overall decrease toward 12z.
KBOS Terminal...Moderate confidence in TAF.
NW to NE winds tonight less than 10 kts. Low end VFR to MVFR
ceilings develop after 15z. Showers likely arrive between 20-22z
with ceilings dropping more uniformly to MVFR. Chance for IFR
overnight.
KBDL Terminal...Moderate confidence in TAF.
Low end VFR to MVFR ceilings develop after 14z. Showers likely
arrive between 18-20z with ceilings dropping more uniformly to
MVFR. Chance for IFR and perhaps LIFR overnight.
Outlook /Monday Night through Thursday/...
Monday Night: Mainly VFR, with local MVFR possible. Breezy.
Chance RA.
Veterans Day through Tuesday Night: VFR. Windy with gusts up to
35 kt.
Wednesday: Mainly VFR, with local MVFR possible. Windy with
gusts up to 30 kt.
Wednesday Night: Mainly VFR, with local MVFR possible. Breezy.
Thursday: VFR. Breezy.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Key Messages:
* SE winds pick up this afternoon to SCA levels. Showers on all
waters this afternoon, with low risk for thunder over the
south. Mist/fog could reduce visby on the waters tonight.
* Sharp cold front late in the day Monday.
* Gale-force westerly gusts looking likely for Tue, perhaps
into early Wed.
Light SE winds this morning will be increasing to around 20-25
kt on most waters by this afternoon and into early tonight. SCAs
have been raised on the waters starting around 17z today and
continue into 12z Mon. Seas will again rebuild to 4-6 ft
offshore. Areas of showers this afternoon lift north early
tonight, but possible mist/fog and drizzle could reduce visbys
on waters tonight.
Light SE to S winds early on Mon until frontal passage.
Windshift to W Mon late aftn with gusts increasing into the SCA
to near-gale levels Mon night.
Outlook /Monday Night through Thursday/...
Monday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Chance of rain.
Veterans Day: Moderate risk for gale force winds with gusts up
to 40 kt. Areas of rough seas. Chance of rain.
Tuesday Night: Moderate risk for gale force winds with gusts up
to 40 kt. Rough seas up to 14 ft.
Wednesday: Strong winds with gusts up to 35 kt. Rough seas up
to 14 ft. Slight chance of rain.
Wednesday Night: Strong winds with gusts up to 35 kt. Areas of
rough seas. Slight chance of rain.
Thursday: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Areas of rough seas. Slight chance of
rain.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides are still running high coming out of the full
moon from late in the week, but should continue to fall during
the Sunday and Monday. Continuing to monitor the high tides
Sunday and Monday mornings at Nantucket for possible minor
coastal flooding, with Stevens Institute supporting about a 1 ft
storm surge. However, Stevens Institute guidance keeps means
below minor flood stage for Nantucket as well as locations like
Boston for the Sun/Mon high tides. However, their "reasonable
worst case" indicates there is potential for Nantucket to reach
minor flood stage Monday.
Will continue to reassess this potential over the next day/two
for possible coastal flood headlines, but significant flooding
is not expected.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from noon today to 7 AM EST Monday for
ANZ230>235-237-250-251-254>256.
&&
$$
SYNOPSIS...Loconto/FT
NEAR TERM...Loconto
SHORT TERM...Loconto
LONG TERM...FT
AVIATION...Loconto/FT
MARINE...Loconto/FT
TIDES/COASTAL FLOODING...Loconto/Mensch
