Quonochontaug, Rhode Island 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

469
FXUS61 KBOX 182320
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
620 PM EST Thu Dec 18 2025

.WHAT HAS CHANGED...
Wind Advisories were upgraded to High Wind Warnings for coastal
Rhode Island and eastern Massachusetts, with Gale Warnings upgraded
to Storm Warnings on all eastern waters.

&&

.KEY MESSAGES...

- Calm conditions this afternoon and evening, becoming unsettled
  by early Friday morning through the afternoon. Period of
  moderate to at times heavy rainfall and strong to damaging
  southerly wind gusts.

- Coastal flooding risk along south coast Friday has ended.

- Improving conditions by Friday evening and through the
  overnight, but windy conditions from the west remain.

- Shortwave brings a period of gusty winds and much colder air
  Sunday night into Monday.

- Weak disturbance may bring a period of light snow Tuesday
  afternoon.

&&

.DISCUSSION...
KEY MESSAGE 1...Calm conditions this afternoon and evening, becoming
unsettled by early Friday morning through the afternoon. Period of
moderate to at times heavy rainfall and strong to damaging southerly
wind gusts.

A 1030mb high-pressure east of Cape Cod provides tranquil conditions
for the remainder of Thursday and the first half of the night. Will
have declining conditions by early Friday morning as a robust rain
and wind system pushes across the northeastern CONUS. The system is
very dynamic with a deep mid-level trough, high moisture content and
an anomalous 850mb jet. Good news, it is a progressive system, let`s
discuss the threats.

Rainfall: Rain overspreads the region from west to east during the
morning, thus leading to a slow commute for some, especially by
midmorning. High moisture content advects northward due to the
strong low-level jet, PWATs surpassing an inch with localized higher
values near the south coast of 1.2". Strong forcing from a robust
mid-level trough and shortwave, will have periods of moderate and
heavy rain, and cannot rule out rumbles of thunder with limited
instability. Areas that could experience a thunderstorm are the
southern coast of RI and south coast of MA, as the best instability
is mainly over the southern waters. High-res guidance also hints at
the chance of a fineline to develop, which could locally enhance
rainfall rates and wind damage. Otherwise, rainfall rates aren`t too
impressive, plus the progressive nature, not expecting significant
flooding. However, areas that normally experience nuisance flooding
could see ponding. Expected amounts of rain are between 0.5 and 1.0
inches, with locally higher values in the higher terrain of
northwestern CT and western MA, where terrain may help to enhance
rainfall totals. Rain moves out by midafternoon and drying out late
afternoon into the evening hours. A rouge orographic snow shower or
two is possible overnight into Saturday morning for northwestern
areas of MA, otherwise dry.

Wind: We continue to monitor the threat for strong to damaging winds
ahead of an approaching cold front. As we`ve previously mentioned an
anomalous 850mb jet with a core of 90 to 100 knots of wind are a few
thousand feet above our heads by early afternoon. Highlighting this
abnormality is the ensemble situational awareness table, showing
the winds at 850mb are 4-5 standard deviations above normal. Now, not
all this wind will mix down to the surface, a thermal inversion at
the surface will keep the strongest winds aloft. Looking slightly
lower at the 925mb winds, winds are muddled ever so slightly 50 to
80 knots over much of the region, with 70 to 90 knots over the east
coast of MA and extreme coastal RI. If 60 percent of that wind field
were to mix to the surface, would have gusts at 60 mph which was the
basis for converting the Wind Advisory to a High Wind Warning for
those areas. Elsewhere the forecast remains on track with potential
gusts of 40 to 55 mph. One thing to keep in mind for tomorrow are
the temperatures, because the warmer we get, the better chance the
thermal inversion eroding. For an example, forecast sounding at KPVD
at 18z shows a neutral to weak inversion, with a surface temperature
of 57F mixing would only extend to 950mb where winds are 50 knots,
but if the temperature were to be 60F the boundary layer would
extend to 925mb where winds are 70 knots. As you can imagine, there
is a 2 to 4 degree make or break when it comes to the wind forecast,
especially the higher end wind gusts.

KEY MESSAGE 2...Coastal flooding risk has ended.

Storm surge forecasts via Stevens Institute and P-ETSS continue to
show a 2 to 3.5 ft storm surge at our south coastal sites
accompanying the period of strong southerly winds Fri. Despite this
rather large storm surge no coastal flooding is expected as this
storm surge looks to peak 3-4 hrs after the mid-morning high tide,
with high confidence.

KEY MESSAGE 3...Improving conditions by Friday evening and through
the overnight, but windy conditions from the west remain.

Cold front moves through, strong cold advection results with a well
mixed boundary layer, support strong west wind gusts. The strongest
gusts between 40 and 50 mph likely be confined to the Berkshires,
Worcester Hills and the Islands... and a low risk for a few 50+ mph
gusts. Elsewhere, potential for a period of 35 to 45 mph gusts. The
strong cold advection results in temperatures falling into and
through the 20s overnight.

KEY MESSAGE 4... Shortwave brings a period of gusty winds and much
colder air Sunday night into Monday

A mid-level shortwave trough moves through late Saturday into Sunday
bringing scattered rain and snow showers mainly across far northern
Massachusetts. The larger concern will be for another period of
elevated winds especially Sunday night into Monday. Continuing to
see two periods of strong low level winds Sunday and Monday. First
will be early Sunday morning as a southwest low level strengthens to
40-50 mph as warm air advection increases. Limiting factor will
timing as the core of the jet passes through between 06-12z. There
will still be locally better mixing (lapse rates between 4-6 C/km)
at coastal locations and across the elevated terrain. These areas
could winds gust as high as 40-45 mph thru 12z Sun. Another round of
more widespread gusty winds arrives later Sunday behind a strong
cold front. Strong mid and low level cold air advection will help to
mix a 40-55 mph low level jet to the surface. Expecting widespread
gusts of 40-45 mph from 00z-15z Monday.

Additional concern for Monday will be a significantly colder airmass
Monday. Temps at 850mb plunge to around -15C which should translate
to low temperatures ranging from the mid teens in the interior to
the mid 20s for the Cape and Islands. These cold temps paired with
strong NW winds push wind chill temperatures down into the lower
single digits in elevated interior areas and lower to middle teens
elsewhere.

KEY MESSAGE 5... Weak disturbance may bring a period of light snow
Tuesday afternoon.

By Tuesday an upper level disturbance over northeast Quebec helps
form a weak surface low near the international border. Guidance
shows a broad area of warm advection on the southern side of the low
as it moves southeast. Forcing from the warm advection could be
enough for widespread snow showers/light snow Tuesday into Tuesday
afternoon. Latest NBM shows a light event with probabilites of
greater than 1 inch of accumulation Tuesday generally below 30
percent and confined to the higher elevations of Massachusetts.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

00Z TAF Update: Unsettled conditions expected to arrive
overnight into Friday morning, worst of conditions peaking early
afternoon, with improvements later in the day. Confidence
continues to increase for southerly gusts of 40 and 50 knots
across much of the region along with periods of moderate and
heavy rainfall.

Today...High Confidence.

VFR. South winds between 5 and 10 knots.

Tonight through Friday...High Confidence in trends.

MVFR/IFR ceilings develop 02-06z with widespread IFR late tonight
into Friday as widespread rain, locally heavy develops from west to
east. Gradually improving conditions after 18z/21z after FROPA and
wind shift to west.

Increasing south winds tonight with max winds during Fri 12-18z with
gusts 35 to 45 knots well inland and 40 to 50 knots in the coastal
plain, peaking over the Cape/Islands around 18z where an isolated
gusts of 55 knots cannot be ruled out. Wind shift to west between
18z and 21z, with gusts between 25 and 35 knots.

Areas of LLWS develop tonight as low level winds increase, peaking
Fri in the coastal plain with a robust LLJ 70 an 80 knots around
2,000 feet.

Friday Night...High Confidence in trends.

Improving to VFR and dry, though a low risk (less than 30 percent)
for upslope snow showers in northwestern Massachusetts overnight.
Westerly winds, gusting 25 to 35 knots.

KBOS Terminal...High confidence in trends. Moderate confidence in
timing.

VFR through the rest of today, then MVFR/IFR between 03z-06z and
windshear possible overnight and into mid-Friday morning with rain
moving in by early morning. Improving conditions after 21z Friday.

KBDL Terminal...High confidence in trends. Moderate confidence in
timing.

VFR through the rest of today, then MVFR/IFR between 02z-05z and
windshear possible overnight and into mid-Friday morning with rain
moving in by early morning. Improving conditions after 19z
Friday.

Outlook /Saturday through Tuesday/...

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

Saturday Night: VFR. Windy with areas of gusts up to 30 kt.

Sunday through Monday: VFR. Windy with local gusts up to 30 kt.

Monday Night: VFR. Breezy.

Tuesday: Mainly VFR, with local MVFR possible. Breezy. Chance
SN, chance RA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight through Friday...High Confidence.

Southerly winds will begin to increase tonight, but especially
toward early morning Friday with onset of gale to storm force gusts.
Gusts to 50 kt now looks to be the case for much of the eastern
outer waters Fri morning to mid-/late-afternoon, which has prompted
upgrading existing gale warnings over to storm warnings. Seas will
build to around 13-16 ft on the outer waters, leading to potentially
dangerous marine conditions. Besides the winds and seas, rounds of
rain showers, some locally enhanced late in the day as a cold front
moves through.

Passage of cold front late in the day will bring WNW winds to gale
force into early Sat, which then decrease as we move through Sat.
Seas will gradually decrease later Fri night to around 9-12 ft, with
a more substantial decrease expected into Sat.

Outlook /Saturday through Tuesday/...

Saturday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Areas of rough seas.

Saturday Night: Low risk for gale force winds with gusts up to
35 kt. Areas of rough seas.

Sunday: Strong winds with gusts up to 35 kt. Rough seas up to
11 ft.

Sunday Night: Strong winds with gusts up to 35 kt. Rough seas
up to 12 ft.

Monday: Strong winds with gusts up to 35 kt. Areas of rough
seas.

Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas.

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Local rough seas. Chance of rain, chance of snow.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory from 4 AM Friday to 1 AM EST Saturday for
     CTZ002>004.
MA...Wind Advisory from 4 AM Friday to 1 AM EST Saturday for
     MAZ002>006-008>014-017-018-026.
     High Wind Warning from 6 AM to 3 PM EST Friday for MAZ007-015-
     016-019>024.
RI...Wind Advisory from 4 AM Friday to 1 AM EST Saturday for
     RIZ001>003.
     High Wind Warning from 6 AM to 3 PM EST Friday for RIZ004>008.
MARINE...Storm Warning from 6 AM to 3 PM EST Friday for ANZ230>234-250-
     251-254-255.
     Gale Warning from 3 AM Friday to 7 AM EST Saturday for ANZ235-
     237-256.
     Gale Warning from 5 AM Friday to 1 AM EST Saturday for ANZ236.

&&

$$

DISCUSSION...Dooley/FT
AVIATION...Dooley/McMinn
MARINE...Loconto