BOX issues Area Forecast Discussion (AFD) at Nov 8, 1:49 PM EST455
FXUS61 KBOX 081849
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
149 PM EST Sun Nov 8 2026
.WHAT HAS CHANGED...
Added a chance of showers on Monday with an approaching upper level
disturbance. Otherwise, no significant changes to the forecast.
&&
.KEY MESSAGES...
- Unsettled weather continues this weekend as slow low pressure
slowly moves away into the Gulf of Maine.
- Cloudy through midweek with more seasonable temperatures.
- Unsettled weather may return late this week.
&&
.DISCUSSION...
- Drier and cooler this afternoon and overnight as deepening low
pressure continues to move away.
- Cloudy and unsettled start to the workweek as multiple weak
disturbances move through.
&&
.DISCUSSION...
KEY MESSAGE 1... Drier and cooler this afternoon and overnight as
deepening low pressure continues to move away.
Visible satellite shows pockets of stratocumulus clouds indicative
of ongoing strong low and mid level cold air advection this
afternoon. Another indicator is the stiff west breeze that will
continue this afternoon as mixing heights rise to >3 kft and tap
into a 35-40 kt LLJ. Model soundings show a well-mixed PBL overnight
and so expect lows to remain a bit warmer than they otherwise could
be. Lows tonight likely remain above freezing, ranging from the mid
30s inland to the low to mid 40s across coastal areas. Greatest
chance of better decoupling and cooler temperatures will be found
across interior valleys where lows may dip into the lower 30s early
Monday morning.
KEY MESSAGE 2...Cloudy and unsettled start to the workweek as
multiple weak disturbances move through.
We remain under WNW flow with another upper level trough clearing
the region through Monday night, and with it cooler temperatures
prevail aloft. 850 mb temperatures look to fall below 0C late Monday
night then steadily improve through the day on Tuesday to around 2-
4C. These cooler conditions aloft will remain supportive of a mix of
clouds and sunshine. Guidance has trended towards more in the way of
isolated to scattered showers Monday afternoon as low level lapse
rates steepen to 8-9 C/km. Best forcing for ascent will be found
across NW Massachusetts so expecting scattered coverage of showers
there and isolated coverage elsewhere. Highs Monday and Tuesday look
to be generally in the 40s and 50s with lows in the 30s. These more
seasonable temperatures are expected to continue through at least
midweek as the WNW to W flow aloft continues. Breezy conditions at
the surface are expected at least for Tuesday as another low looks
to pass to our northeast.
KEY MESSAGE 3...Monitoring potential storminess late this week into
part of the weekend, with lower elevation rain and higher elevation
rain mixing with wet snow possible.
Model-ensembles and AI-based guidance continue to point to potential
late-week / early-weekend storminess. However these models continue
to vary on the placement, strength and eventual exit of the modeled
surface low; as well as the thermal structure and more specifically,
the extent to which sub-freezing air aloft can penetrate into
Southern New England. A lead shortwave disturbance coming out of the
north-central Rockies Tue moves into the central Plains around early
Wed; then the 500 mb CONUS pattern amplifies substantially as strong
Pacific trough energy induces amplifying upper ridging across the
Rockies by midweek. Strong northerly 500 mb flow then helps allow
for additional pieces of shortwave energy coming out of the northern
Canadian Prairies/northern Canada to dig southward and/or
potentially phase with the Rockies trough around Thursday/Thursday
night. It's a complicated interaction and how those pieces come
together are critical in terms of resolving the above described
uncertainties. The net result is a deep upper trough/closed low at
500 mb located somewhere in the OH/TN Valleys; and an organizing
surface low moving northward from the mid-Atlantic states Thursday
night, and over or in vicinity of Southern New England around
Friday, with lingering influence possibly into the upcoming weekend.
Latest guidance indicates that sub-freezing air aloft could struggle
to make it into Southern New England at least initially, only then
slowly bleeding into interior higher terrain areas in Southern New
England late Friday night and/or into Saturday, possibly
facilitating a rain to a gloppy wet snow changeover in the higher
terrain. Lower elevations and the coastal plain seem more favored to
stay as primarily rain due to both above-freezing air aloft and the
influx of "milder" onshore flow of maritime air (SSTs still in the
mid 50s). The GFS-based guidance has shown a westward/inland trend
over the past few cycles which is a warmer and wetter outcome. The
international guidance is closer to the 40N/70W benchmark or even
further east, which would bring colder air in sooner but would in
turn also be more removed from the best moisture/modeled QPF.
Highest ensemble probabilities for an inch or more of snow at a 10:1
SLR across the interior higher terrain are still in the moderate
range at around 40-60% and are less than 20% for snow totals of 3 or
more inches.
Still is time to reassess the guidance, and continued variation in
the guidance is likely over the coming days, at least until the lead
shortwave becomes better resolved as it comes out of the Rockies
around Tuesday.
KEY MESSAGE 4...Cloudy, cool, and blustery weather for late weekend
into early next week.
Depending on exactly when the late week/early weekend cyclone pulls
away, we'll be left in a cool cyclonic flow aloft. Expect
considerable cloudiness and cool temperatures, to go along with
blustery northerly winds into early next week.&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Rest of Today...High confidence.
Mostly VFR with pockets of MVFR lingering across the higher
terrain. Expect any lingering MVFR to improve to VFR by 20-22z.
W winds 10-15 kt with gusts as high as 30 kt through the
remainder of the afternoon.
Tonight...High confidence.
VFR. SW winds generally 5-10 kt with winds slightly higher
towards the Cape and Islands. Cloud cover increases after
midnight with ceilings starting to decline over western MA.
Monday...High confidence.
VFR for most. Local MVFR possible across the higher terrain of
central and western MA. Mainly dry, but perhaps a few showers
towards western MA.
KBOS Terminal...High confidence in TAF.
KBDL Terminal...High confidence in TAF.
Outlook /Monday Night through Friday/...
Tuesday through Veterans Day: VFR. Breezy.
Wednesday Night: VFR.
Thursday: VFR. Breezy. Chance RA.
Thursday Night: VFR. Windy with areas of gusts up to 30 kt. RA
likely.
Friday: Mainly VFR, with local IFR possible. Windy with gusts
up to 35 kt. RA likely, SN likely.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Through Monday...High confidence.
Lingering rough seas, mainly across the southern outer coastal
waters. The rough seas across those waters are likely to persist
through at least Monday night, and perhaps longer. SCA
conditions likely in these areas.
Outlook /Monday Night through Friday/...
Tuesday through Tuesday Night: Low risk for Small Craft
Advisory winds with gusts up to 25 kt. Seas up to 5 ft.
Veterans Day: Winds less than 25 kt. Seas up to 5 ft.
Wednesday Night: Winds less than 25 kt.
Thursday: Winds less than 25 kt. Chance of rain.
Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Seas locally approaching 5 ft. Chance
of rain, slight chance of thunderstorms.
Friday: Strong winds with gusts up to 40 kt. Rough seas up to
12 ft. Rain.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for ANZ230-
231-234-236-251.
Small Craft Advisory until 7 PM EST this evening for ANZ232-
233-235-237-250.
Small Craft Advisory until 7 PM EST Tuesday for ANZ254>256.
&&
$$
DISCUSSION...Loconto/FT
AVIATION...Belk/FT
MARINE...Belk/FT
Source:
BOX issues Area Forecast Discussion (AFD) at Nov 8, 1:49 PM EST----------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
