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348
FXUS61 KBOX 300724
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
324 AM EDT Thu May 30 2024

.SYNOPSIS...
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Low pressure then brings a more widespread rain, moderate to
heavy at times this morning, then slowly dries out during the
afternoon from west to east. Drier weather with plentiful
sunshine for Friday. After a few days of temperatures at or
slightly cooler than normal, the weekend into Monday offers a
warming trend toward above normal temperatures and still
tolerable humidity levels. Drier weather should generally
prevail this weekend into at least Tuesday.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Highlights:

* Light to moderate rain, at times locally heavy this morning.

* Rain ends west to east late morning into early afternoon, spot
  showers may linger across eastern MA well into mid afternoon.

* Cooler with highs in the 60s and low 70s.

A robust shortwave and weak surface low pressure system will bring
widespread rain across southern New England this morning. Moderate
to at times heavy rainfall rates leads to a slow A.M. commute. These
showers are slow moving, generally 20 knots or less per storm speed
based off KBOX/KOKX. Fortunately, rainfall rates have been light to
moderate, thus no hydro concerns as of yet. 00z HREF guidance does
suggest there is a 50 percent chance for 1.0 inch of rain over an
three hour period, around 12z to 15z. As of this time we are not
concerned with Flash Flooding, though minor street flooding caused
by poor drainage/ponding is possible, especially urban areas.

Still feel rain amounts will be in the neighborhood of a third and
two thirds of an inch. There remains low probabilities for thunder
this morning, with elevated instability - embedded thunder could
lead to locally higher rainfall amounts of 1.0.

Dry slot moves in this afternoon and rain ends from west to east,
rain ending likely before noon for western MA and CT. Little later
for eastern MA and RI, though north/northeast flow may keep spotty
showers in eastern MA ongoing into the afternoon. Sun breaks out mid
afternoon across western MA northern CT, though eastern areas it may
take until late afternoon - prior to sunset before the sun breaks
outs.

The north/northeast flow will keep eastern MA into RI the coolest
spot this afternoon in the low to middle 60s. Further inland,
temperatures are upper 60s and low 70s, warmest in the CT River
Valley.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
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Highlights:

* Cooler tonight, followed by a beautiful Friday.

Mid-level trough moves off shore overnight, a rouge shower not out
of the question across the Cape and Island. That said, trend is
drying along with with clearing skies. Noticeably cooler
tonight with temperatures in the 40s to low 50s. Coolest in NW
MA where the low drops into the lower 40s. Light north wind
overnight, chance that the winds decouple and we are slightly
cooler than forecast. With light winds and the rain from today,
areas or patchy radiational fog is not out of the question.

Mid-level ridging on Friday with surface high pressure will lead to
a wonderful day with sunny conditions and warm temperatures in the
70s. Guidance does hint towards a seabreeze along the coast, likely
keeping those communities a tad cooler.
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.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
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Key Points...

* Temperatures will be increasing steadily each day through
  early next week into the 80s.

* An extended stretch of mostly dry weather is expected through
  Wednesday but there is a chance for some scattered showers late
  Sunday then isolated showers each afternoon thereafter.

Details...

Quiet weather continues for the weekend and well into next week
thanks to a broad ridge of high pressure in the mid levels and high
pressure at the surface. This means mostly dry and sunny/partly
sunny conditions for the weekend and even through the middle of next
week. The one period to watch for the potential of some unsettled
weather would be later Sunday into Monday as global guidance shows a
weak shortwave dampening the ridge; however, some of the guidance
shows this being suppressed too far south to impact SNE so
confidence is low at this time that we`ll see any wet weather.
Ensemble guidance places the odds of measurable rainfall during this
period at 40-60% for western MA/CT and less further east. Either
way, not expecting a washout. As for Monday through Wednesday, each
day will feature the chance for a few diurnally driven showers in
the afternoon, especially away from the coasts but most should stay
dry.

Temperature-wise we`ll kick off the weekend seasonable to slightly
above seasonable for the start of June, with highs in the 70s to low
80s (CT valley). As the ridge builds in the airmass will continue to
warm each day into Monday when highs will reach into the mid 80s
inland and low to mid 70s along the coasts. This will continue to be
the case through mid week before our next shortwave approaches
bringing the chance for cooler temps and wet weather toward the end
of next week.
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&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Forecast Confidence Levels:

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

06Z TAF Update: High confidence on trends, lower on exact
timing and details.

Through 12z... High confidence on trends, lower on exact
timing and details.

VFR with rain spreading in from southwest to northeast, CIGS
fall to MVFR 9z-12z south of the Mass Pike, with low end VFR
CIGS north. Widely isolated showers continue to bubble up ahead
of the main area of rain, added TEMPO group to site that could
see a brief shower with lower CIGS. Light winds will increase
around 12z and/or shortly after.

Today... High confidence on trends, lower on exact
timing and details.

Rain becoming widespread after 12z, MVFR/IFR CIGS for through
18z, rain tapers off from west to east with improving CIGS, it
will take some time for the I-95 corridor to lift from IFR to
MVFR, somewhere around 20z-22z. Gusty north/northeast winds are
10 to 20 knots.

Tonight... High confidence on trends, lower on exact
timing and details.

Lingering MVFR/IFR CIGS across Cape Cod and Nantucket, with a
low probability for a light rain shower. Otherwise, VFR CIGS
prevails along with dry weather. North/northwest winds are less
than 10 knots, while the coast winds are less than 15 knots.

Friday... High confidence.

Dry and VFR. Light northwest winds across the interior and
seabreeze along the coast.

KBOS TAF... High confidence in trends with moderate confidence
in timing.

CIGS are VFR early, becoming MVFR with widespread moderate rain
between 10z and 12z, likely a few hit and miss showers before
hand, have run a TEMPO for this chance. By 13z to 15z, IFR CIGS
and continued rain - which could become heavy at times. Winds
are north/northeast, gusting to 20 knots this morning into early
afternoon. MVFR conditions return after 18z with rain ending.
Could take some time for VFR CIGS to return, possible not until
21z to 23z. Becoming VFR with light northwest winds overnight.
VFR and dry on Friday with a likely seabreeze.

KBDL TAF... High confidence in trends with moderate confidence
in timing.

CIGS are VFR early, widespread rain arriving between 06z and 08z
and CIGS are falling shortly after to MVFR. Should maintain MVFR
CIGS this morning with moderate to at times heavy rainfall, the
rain continues through at least 12z to 14z with improvement to
VFR after 18z. North wind around 10 knots. VFR tonight into
Friday with dry conditions.

Outlook /Friday Night through Monday/...

VFR.

&&

.MARINE...
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Forecaster Confidence Levels:

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

Today through Friday...

Weak surface low pressure system brings widespread rain, at
times heavy this morning into early afternoon, a few lingering
showers are possible this evening, although the trend is to dry
things out. A period of gusty NNE wind this afternoon 20 to 24
knots and building seas to 3-5 ft along the eastern outer
waters. Have opt for a SCA for the outer eastern waters this
afternoon into early evening for marginal seas.

Dry with light northwest winds on Friday morning, wind becomes
southwest later in the day less than 15 knots.

Outlook /Friday Night through Monday/...

Winds less than 25 kt.
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&&

.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 11 AM this morning to 8 PM EDT this
     evening for ANZ250-254.
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&&

$$

SYNOPSIS...BW/Dooley
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...BW
AVIATION...BW/Dooley
MARINE...BW/Dooley