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823
FXUS61 KBOX 171111
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
711 AM EDT Tue Sep 17 2024

.SYNOPSIS...
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High pressure continues to support warm/dry weather through at
least Wednesday evening, when we`ll have our next chance for
measurable precipitation. Chances should be confined to Cape Cod
and the Islands. Otherwise, mainly dry with mostly cloudy
conditions and blustery NE winds through this weekend.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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Today

Surface ridging associated with high pressure off the east coast
will continue to support warm/dry weather today. Moist easterly
flow beneath a low-level inversion will allow for areas of dense
fog this morning mainly south of I-90/Mass Pike. Expect fog to
lift by mid to late morning in response to surface heating.
Today should feature a bit more cloud cover than we`ve grown
accustomed to during the recent stretch of sunny/dry weather as
high cirrus associated with low pressure over the southeastern
US pushes over The Northeast. Despite some some high cirrus,
there should still be plenty of sunshine and more warm
temperatures in the upper 70s to low 80s. Sea- breezes will keep
the coastal areas a bit cooler in the low to mid 70s.
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&&

.SHORT TERM /WEDNESDAY/...
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Tonight

High pressure off the east coast builds further east overnight
as low-pressure advances from the south. This will support a
wind shift to the east/northeast along the south coast where
there will be increasing cloudiness overnight. Further across
the interior winds will be more in the light/variable category.
Expect some patchy areas of fog once again with the boundary
layer nearly saturated beneath a strong low-level inversion at
950 hPa. Some light drizzle possible over the south coast, Cape,
and Islands as well.

Tomorrow

Sunny/dry weather comes to an end tomorrow as low-pressure and
tropical moisture advances from the south. Winds take on an
easterly component which will support a steady onshore flow
along the east coast. Expect overcast skies and patchy drizzle
Wednesday morning. Chances for more persistent showers will
increase into the afternoon and evening as the surface low
advances further north. Guidance has been trending toward a
slower arrival of showers, but the greatest chance for showers
Wednesday afternoon/evening exists over The Cape and Islands.
Despite the cloud cover and increased rain chances the air mass
will remain anomalously warm and humid with highs in the mid to
upper 70s and dewpoints in the low to mid 60s.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
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Latest guidance suite continued to show at least broad agreement
on the overall theme of the forecast, but agreement with the
details still remained elusive. Tried to trend the forecast with
this update towards the consensus solution, without making large
changes just yet.

Overall, expecting a mid level trough to be nearby late this
week into early this weekend. This will provide our next chance
for some showers. It has been some time since we have had
measurable rainfall for most of southern New England, so we have
capacity to handle quite a bit of rainfall. Have the greatest
confidence in rainfall across the Cape and islands, with lower
confidence towards the NW. This uncertainty stems from the
combination of how strong a ridge of high pressure will be
across our region, and how close a low pressure can approach
from the south. At this time, thinking it is most likely this
low pressure travels just SE of the 40N/70W benchmark.

Another aspect which will need to be monitored closely with this
low pressure is coastal flooding. Astronomical tides are rather
high later this week. A slow-moving low pressure with persistent
winds with at least some onshore component for the south coast
of New England may result in pockets of coastal flooding issues
late this week.

High pressure should then build into our region from the N this
weekend into early next week, leading to more dry weather.

Temperatures anticipated to trend below normal by this weekend,
and continue into early next week.
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&&

.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
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Forecast Confidence Levels:

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

Today...High Confidence

Areas of IFR/LIFR fog/low stratus burns off by 14-15Z. VFR
thereafter with light south winds. Sea-breezes developing along
the coast by 16Z.

Tonight...High Confidence

More patchy fog development tonight with localized IFR vsbys.
MVFR/IFR ceilings over the south coast, Cape, and Islands.
Light and variable winds.

Tomorrow...High Confidence

VFR with shower chances increasing over The Cape/Islands by 00Z.
Light easterly winds 5 to 10 knots.

KBOS TAF...High confidence in TAF. VFR. SE seabreeze kick in
between 15-17z, around 10 kts, becoming southerly 22-00z.

KBDL TAF...High confidence in TAF. VFR with light winds. IFR
fog/stratus could develop around 08-10z Tue.

Outlook /Wednesday Night through Saturday/...

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

Thursday: Mainly VFR, with local MVFR possible. Breezy. Slight
chance SHRA.

Thursday Night: VFR. Slight chance SHRA.

Friday: Mainly VFR, with local MVFR possible. Breezy. Slight
chance SHRA.

Friday Night: VFR. Breezy. Slight chance SHRA.

Saturday: VFR. Breezy.
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&&

.MARINE...
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Forecaster Confidence Levels:

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

Marine

Today and Tonight

High pressure just east of the coastal waters continues to
support calm/tranquil boating condition through at least
Wednesday morning. Winds remain modest at speeds less than 10 kt
knots out of the south/southeast. Seas range from 0 to 1 feet in
the near- shore zones and 2 to 3 feet over the outer waters.

Wednesday

Low-pressure approaching from the south will result in rising
seas over the south coastal waters. Small Craft Advisories will
likely be needed with seas rising to 5 to 6 feet over the
coastal waters south of MVY and Block Island by Wednesday
evening.

Outlook /Wednesday Night through Saturday/...

Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers.

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

Friday: Winds less than 25 kt. Seas up to 5 ft. Slight chance
of rain showers.

Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. Slight chance of rain
showers.

Saturday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Rough seas up to 8 ft.
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&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...Belk/RM
NEAR TERM...Belk/RM
SHORT TERM...RM
LONG TERM...Belk
AVIATION...Belk/RM
MARINE...Belk/RM