175
FXUS61 KBOX 170632
AFDBOX

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

.SYNOPSIS...

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.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

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.


&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...

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.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...

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.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
Forecast Confidence Levels:

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

Through 12Z...High Confidence in Trends

Light southwest or light/variable winds persist this evening.
Fog already developing across portions of the south coast and
southeastern MA. Expect additional areas of fog to develop in CT
River Valley near BDL. Fog/low stratus will likely support some
areas of IFR/LIFR conditions through sunrise.

Today...High Confidence

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.

&&

.MARINE...
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 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. SCY headlines 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.

&&

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

&&

$$

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