479
FXUS61 KBOX 221737
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
137 PM EDT Sun Sep 22 2024

.SYNOPSIS...
Rain near the coast will slowly come to an end today as low
pressure southeast of New England will moves farther out to
sea. Weak high pressure will build over the region Monday and
Tuesday, but continued onshore winds should keep cloudiness
over southern New England, especially near the coast. Rain
chances increase again around midweek as a front approaches from
the Great Lakes.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM update...

Offshore storm still having some impact on coastal SNE with lots
of cloud cover and gusty NE winds. Rain shield has shifted to
the south but northern edge still impacting the Islands with a
few showers. Trend will be for drying here but a few light
showers may rotate in from the east with a brief shower
possible across portions of eastern MA and RI this morning.
Otherwise, the column is drying especially in the interior which
will lead to partly sunny skies developing through the
afternoon, but clouds will dominate closer to coastal SE MA and
Cape/Islands. Gusty NE winds continue near the coast with gusts
to 30 mph Cape/Islands. Highs will reach mid-upper 60s with some
lower 70s in the CT valley.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Ridging at surface and aloft begins to take hold tonight and
Monday leading to drier weather overall. Model cross sections
still show plenty of lower level moisture, however, especially
near coast tonight which should result in low clouds and
possibly some drizzle as well. Clouds should dominate Monday but
expect breaks of sun, especially inland.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Highlights...

* Onshore surface flow much of the upcoming week will yield
  generally dreary conditions

* Frontal system sometime mid to late week brings another chance for
  rain

High pressure centered over the Saint Lawrence River will nudge
its way across southern New England. While keeping the forecast
mainly dry into Wednesday, being on the southern periphery with
the weaker subsidence, along with the persistent onshore flow,
should result in plenty of clouds much of this week.

Wednesday still looks to be the transition day as this high
pressure moves farther east. Latest guidance suite has trended
slower with the arrival of showers, but may still not be quite
slow enough given the synoptic pattern. Starting to think much
of Wednesday will be dry as well, especially across the eastern
half of southern New England. Only have moderate confidence in
the current forecast timing.

Still looking more unsettled toward the end of next week as a
low pressure passes by our region. Plenty of uncertainty in the
details, but there is still plenty of time to refine the
forecast timing.

The persistent easterly onshore flow will maintain at least an
elevated risk for rip currents and rough surf into Tuesday.

&&

.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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

18Z TAF Update: Moderate confidence.

Mainly VFR in the CT valley, with a mix of VFR-MVFR cigs
elsewhere. MVFR cigs will be more prevalent near the south
coast and Cape/Islands tonight which may expand across eastern
New Eng Monday morning before improving in the afternoon. MVFR
cigs expected to redevelop across the region Mon night. Patchy
fog may develop in portions of the CT valley late tonight and
late Mon night.

NE gusts to 25 kt Cape/Islands into this evening before slowly
diminishing late tonight and Mon, but gusts to 20 kt will
persist into Mon evening.

BOS TAF...Moderate confidence due to timing of ceiling
changes. VFR cigs through tonight trending to MVFR toward
12z. SCT MVFR cloud bases may briefly go BKN through 21z.

BDL TAF... High Confidence.

Outlook /Tuesday through Thursday/...

Tuesday: Mainly VFR, with areas MVFR possible. Breezy.

Tuesday Night: Mainly VFR, with areas MVFR possible.

Wednesday: Mainly VFR, with local IFR possible. Slight chance
SHRA.

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

Thursday: Mainly VFR, with areas IFR possible. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Overall high confidence through Monday. Maintaining SCA
headlines for all waters except Boston Harbor and Narragansett
Bay.

Low pressure offshore remains close enough today to maintain
strong NE winds gusting to 25-30kt, with strongest gusts around
Cape Cod and Islands where some marginal Gales are possible at
times today. NE winds gradually subside tonight and Monday as
low heads farther SE away from region but rough seas should
persist, especially on open waters.

Rain gradually diminishes today but may linger most of day on
waters south and east of Cape Cod.

Outlook /Monday Night through Thursday/...

Monday: Low risk for Small Craft Advisory winds with gusts up
to 20 kt. Rough seas up to 11 ft.

Monday Night: Winds less than 25 kt. Rough seas up to 9 ft.

Tuesday through Tuesday Night: Winds less than 25 kt. Rough
seas up to 8 ft.

Wednesday: Winds less than 25 kt. Areas of rough seas.

Wednesday Night: Winds less than 25 kt. Areas of rough seas.
Chance of rain showers.

Thursday: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain showers.

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Advisory remains in effect for afternoon high
tide today. While astronomical tides remain elevated, the tides
are slowly coming down from the peak Fri and Sat. Still
expecting a surge of 1-1.5 ft which will result in shallow
flooding less than one foot deep of more vulnerable locations.

High Surf Advisory remains posted due to high seas and rough
surf which will continue today.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Surf Advisory until 8 PM EDT this evening for MAZ007-019-
     020-022>024.
     Coastal Flood Advisory until 6 PM EDT this evening for MAZ007-
     015-016-019-022>024.
RI...High Surf Advisory until 8 PM EDT this evening for RIZ006>008.
MARINE...Small Craft Advisory until 6 PM EDT Monday for ANZ231>235-237-
     250-251-254>256.

&&

$$

SYNOPSIS...Belk/JWD
NEAR TERM...KJC
SHORT TERM...JWD
LONG TERM...Belk
AVIATION...KJC/JWD
MARINE...Belk/JWD
TIDES/COASTAL FLOODING...JWD