008
FXUS61 KBOX 222349
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
649 PM EST Fri Nov 22 2024

.SYNOPSIS...
The next slug of rain will overspread the region from east to west
as the night wears along with any wet snow confined to the highest
terrain...but no impacts are expected. The rain will persist into
Saturday morning and even into the afternoon across parts of eastern
Massachusetts and Rhode Island. As low pressure off the coast
intensifies...it will become windy Saturday afternoon into Saturday
night. Dry and blustery weather is on tap for Sunday to close
out the weekend. The rest of the week looks active, with one
storm system around Tuesday spreading rain showers. Blustery,
cooler and dry for Wednesday, then monitoring for additional
storminess around Thanksgiving or Black Friday.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
350 PM Update...

* Rain develops this eve in eastern MA/RI & spreads west overnight
* Any wet snow & very minor accums confined to highest terrain

The vertically stacked low pressure system to our west will
gradually sink southeast and be located south of Long Island toward
daybreak. As this happens...secondary low pressure east of the
Benchmark will rapidly intensify and lift northward tonight. This
will allow another swath of widespread rain to overspread eastern MA
& RI tonight. While the focus for the rain will initially be across
eastern MA/RI...the rain should back into the interior during the
late night and overnight hours with good mid level frontogenesis.

The boundary layer will be warm enough to result in Ptype falling as
generally rain. Thermal profiles might become marginally cold enough
across the high terrain of the Berks/Worcester Hills to support
some wet snow during heavier precipitation rates. Any snow accums
will probably be just a dusting to 1 inch mainly on grassy surfaces.
Suppose there is a low risk of 2 inches if boundary layer ends up
colder than forecast. But like last night and earlier this
morning...not really expecting any impacts and any very minor accums
confined to the highest terrain. Overnight low temps should bottom
out in the middle 30s to the lower 40s.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Key Messages...

* Rain Sat morning persists into the afternoon in eastern MA/RI
* Becoming Windy Sat afternoon/evening with NW gusts of 35-45+ mph
* Highs Sat will be in the 40s and the wind will make it feel colder

Details...

Saturday and Saturday night...

A secondary surface low pressure system east of our region will
rapidly intensify and lift northward on Sat. A cold rain will be
impacting much of the region Sat morning...but the back edge of this
precipitation will be pushing eastward as the low pulls away.
Again...any wet snow should be pretty much confined to the high
terrain and should not be impactful. Otherwise...the rain should
come to an end by afternoon across the interior but will linger into
at least part of the afternoon across parts of eastern MA and RI.

The other issue will be the strong winds that will develop on
Sat...especially during the afternoon and into the evening. As this
ocean storm intensifies and lifts northward the pressure gradient
will increase. A northwest low level jet of 45 to 55 knots will
develop at 850 mb. Bufkit soundings indicate northwest wind gusts of
35-45+ mph will mix down Sat afternoon and evening. The strongest
winds will likely be in the interior and it is not out of the
question that a few brief gusts of 50 mph occur. Later shifts may
need to consider a Wind Advisory...but given it is in the latter
half of the 3rd and into the 4th period figured we would let the
next shift take a look. High temps on Sat will be held in the 40s
and with the windy conditions will make it feel colder...especially
with the rain!

Any lingering rain should pretty much be over by late
afternoon/early evening along the coast...but the windy conditions
will persist with 35-45+ mph wind gusts continuing during the
evening. Winds may drop off a tad overnight...but it still will
remain windy. Low temps Sat night should only drop in the middle 30s
to the lower 40s given the atmosphere will not decouple.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Key Points:

    *Dry northwest flow continues into Sunday with blustery winds.

    *Dry and less windy Monday.

    *Chance for rain and showers on Tuesday, then dry and windy
     again on Wednesday.

    *Low confidence forecast heading into the long Thanksgiving
     weekend with a chance at wintery precip.


Continued dry and bluster NW winds to start Sunday with gusts of 25-
35mph in the morning.  The pressure gradient relaxes Sunday
afternoon to evening, with winds falling to 10-15mph after sunset.
Quick passing ridge and high-pressure build-in from the south for
Monday will keep dry conditions around with much less wind compared
to the weekend.  High temps on Sunday and Monday stay near
seasonable levels in the upper 40s to low 50s.

A fast-moving shortwave trough exits the Great Lakes Tuesday night,
with the majority of the energy passing to the north across northern
New England. Rain looks more showery than steady rain at this time,
but a shift south in the low-pressure track could bring more
consistent rain.  The highest QPF totals will likely be north of the
MA pike, closer to the better forcing, but likely remain under a
half inch.  Ensemble guidance from the GEFS, EPS, and CMCE are in
good agreement with high probs for a tenth inch of rain but low to
zero probs for a half inch of rain.  A cold front moves through late
Tuesday, drying things out and bringing gusty NW winds again for
Wednesday.  Winds look to be around 15-20mph with gusts of 25-30mph
for much of the day.  High temps on Tuesday warm into the low to mid-
50s but drop on Wednesday into the low to mid-40s.

Forecast confidence drops significantly heading into the long
Thanksgiving weekend as guidance hints at a low-pressure system that
could bring wintery precipitation.  The timing and strength of that
system remain very mixed among the deterministic guidance sources
with little run-to-run consistency.  Ensemble guidance doesnt paint
a clearer picture with significant differences in QPF and snow
chances between the GEFS and EPS systems.  GEFS has a 10% chance or
less for 1in of snow, while the EPS has a 30-50% chance.  This
system will be watched closely over the weekend and into next week,
especially with the upcoming busy Thanksgiving travel weekend.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Forecast Confidence Levels:

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

00z TAF Update...

Tonight...Moderate Confidence.

Rain and MVFR CIGS continues to spread from south to north with
steady light to moderate rain through the night for eastern
terminals. More off and on rain showers across western
terminals. There could be pockets of IFR CIGS esspically near
coastal terminals. Winds will turn NE this evening at 5-10
knots before turning NNW late overnight. Winds will become gusty
up to 30 knots once the winds shift NNW.

Saturday...Moderate Confidence.

Widespread MVFR/IFR conditions and rain Saturday morning
especially for Eastern MA and RI. Ptype will generally be
rain, but some wet snow is possible in the high terrain of the
Berks/Worcester Hills but any accums will be very minor and not
much of an impact. Conditions will improve to VFR Sat afternoon
across the interior, but rain and scattered MVFR cigs/vsbys
could linger into Sat afternoon across parts of eastern MA & RI.
NW winds will increase to between 15 and 25 knots with gusts of
30 to 40 knots developing during the afternoon. The strongest
of those wind gusts should be across the interior.

Saturday night...Moderate Confidence.

Any lingering MVFR ceilings near the coast will depart early in
the evening. Otherwise VFR with NW wind gusts of 30 to 40 knots
in the evening decreasing to 20-30 knots overnight.

KBOS Terminal...Moderate Confidence in TAF.

Rain and MVFR/IFR CIGs overnight. Winds turn NE late this
evening before turning NW late overnight. Winds become gusty
once they turn NW up to 30 knots. Gusty NW winds tomorrow up to
40 knots with periods of light to moderate rain.

KBDL Terminal...Moderate Confidence in TAF.

VFR becoming MVFR overnight with off and on rain. Winds turn NE
late this evening before becoming NNW by Saturday morning.
Gusty NNW winds during the day Saturday up to 35 knots. Showers
may linger into Saturday afternoon.

Outlook /Sunday through Wednesday/...

Sunday: VFR. Windy with gusts up to 35 kt.

Sunday Night through Monday: VFR. Breezy.

Monday Night: Mainly VFR, with local MVFR possible. Chance RA.

Tuesday: Mainly VFR, with local IFR possible. Breezy. RA
likely.

Tuesday Night through Wednesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Tonight through Saturday night...High Confidence.

* Gale Warnings Sat afternoon and night

Low pressure east of the Benchmark will rapidly intensify as it
lifts northward tonight into Sat. In response...ESE winds at 5 to 15
knots early this evening will shift to the NE later tonight and NW
by daybreak Sat. These winds will also begin to increase and with
the strong pressure gradient developing expecting NW wind gusts of
30-40 knots Saturday afternoon and night. Gale Warnings have been
hoisted for all our waters over this time.

Outlook /Sunday through Wednesday/...

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

Sunday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas.

Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.

Monday Night: Winds less than 25 kt. Chance of rain.

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

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Areas of rough seas. Chance of rain.

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Gale Warning from 11 AM Saturday to 4 AM EST Sunday for ANZ230-
     236.
     Gale Warning from 11 AM Saturday to 7 AM EST Sunday for
     ANZ231>235-237-250-251-254>256.

&&

$$

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