737
FXUS61 KBOX 220521
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
121 AM 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 /THROUGH TODAY/...
Slow improvement is the theme for today`s forecast as offshore
low takes its time heading farther out to sea. Radar trends
continue to show erosion of its rain shield over eastern MA as
drier air aloft is working into region from north, and as
surface ridging continues to take hold today, we should see rain
continue to diminish, but probably not until around sunrise in
most of eastern MA and later this morning near Cape Cod and
Islands. It`s possible we even see some breaks of sunshine this
afternoon.

Farther west, there`s still enough low level moisture present to
maintain at least some cloudiness today, but certainly better
chances of seeing sun break out as you head toward the CT River
Valley and east slopes of the Berkshires.

Still a windy day across SE MA, especially on Cape Cod and
Islands where 25-35 mph gusts are expected most of the day.

&&

.SHORT TERM /TONIGHT 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 week will yield generally dreary
  conditions

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

Low pressure that brought much needed rainfall to eastern southern
New England over the weekend will continue to shift to our
southeast, out into the more open Atlantic, early next week. While
the low wont have a dominant effect on our weather for next work
week, it will meander around the Bermuda area for a good portion of
the week. For Tuesday and Wednesday, mid level ridging will build
across the mid-Atlantic, leaving us in the northern fringes of the
ridge, but onshore surface flow will counteract any expected warming
effects from the ridge. Given onshore flow, expecting considerable
cloudiness much of the week.

Mid level cutoff low begins to develop mid week and its associated
trough will cut south into southern Quebec and northern New England
on Wednesday and Thursday. Front associated with this cutoff will
bring our next best chance for rain. Trough remains draped over
southern New England through at least Saturday, which will support
unsettled, showery conditions to round out the work week and start
the weekend.

Temperatures look to respect the page turn from astronomical Summer
to astronomical Fall, which occurs on Sunday the 21st. Highs will be
below normal to start the week ranging from the upper 50s in the
high terrain of western and central MA to the mid 60s to low 70s
elsewhere the first half of the week. Gradual warming trend is
possible late week, with widespread highs in the 70s expected Friday
and Saturday.

As mentioned by the previous forecaster, persistent onshore flow
will lead to a continued risk for rip currents and high surf through
at least Tuesday. With the Harvest Moon waning, coastal flooding
concerns will decrease each day, though it is possible some
splashover occurs during the Monday daylight high tide.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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

06Z Update: Moderate confidence (40%) due to timing of ceilings.

Rain and IFR ceilings near Cape Cod and Islands will linger
through sunrise before rain tapers off and ceilings improve to
MVFR where they should remain all day with NE winds gusting to
25-30kt. Rain will diminish before sunrise in much of RI and
eastern MA where MVFR ceilings should lift to VFR for a few
hours before returning 12-14z, then improving to VFR again
during afternoon. Farther west, VFR ceilings prevail except near
KORH where IFR ceilings improve to MVFR this morning and to VFR
this afternoon.

VFR tonight, but coastal areas should see MVFR ceilings with
possible drizzle at times. Improvement to VFR Monday, but
probably not until early afternoon near coast with continued NE
winds, although lighter.

BOS TAF...Moderate confidence due to timing of ceiling changes.
MVFR ceilings may not return as quickly as forecast this morning
and again tonight.

BDL TAF... High Confidence.

Outlook /Monday Night through Thursday/...

Monday Night: Mainly VFR, with local MVFR possible. Breezy.

Tuesday: Mainly VFR, with areas MVFR possible.

Tuesday Night: Mainly VFR, with local IFR possible.

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

Wednesday Night through 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 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. Seas up to 5 ft. Chance
of rain showers.

Thursday: Winds less than 25 kt. Areas of rough seas. 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 from noon today to 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 8 AM EDT Monday for ANZ231-232-250-
     251-254>256.
     Small Craft Advisory until 2 AM EDT Monday for ANZ233>235-237.

&&

$$

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