903
FXUS61 KBOX 180703
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
303 AM EDT Wed Sep 18 2024

.SYNOPSIS...
High pressure continues to support warm and mainly dry weather
through this afternoon. We`ll have our next chance for measurable
precipitation later tonight. Greatest chances should be confined to
Cape Cod and the Islands. Otherwise, mainly dry with mostly cloudy
conditions and blustery NE winds this weekend into early next week.
&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
3AM Update

Today

Dense fog advisory in effect through 14Z. Areas of dense fog in
the CT River Valley and across southeastern MA and RI will
slowly mix out by late morning and perhaps as late as early
afternoon over The Cape Islands. This will be followed by
another mild say with highs in the upper 70s to low 80s and
increasing mid-high clouds south of I-90. Expect more sun than
clouds for areas north of I-90 away from the coast. Winds become
more easterly during the afternoon which should support
cloudiness along the east coastline. Some patchy areas of
drizzle possibly this morning as well. An area of low- pressure
moving north along the mid- Atlantic coast will result in
increased rain chances this evening over the south coast Cape
and Islands, but showers likely don`t move over the region until
the overnight hours.


&&

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

Tonight and Tomorrow

Aforementioned area of low pressure slowly moves north and east
overnight into tomorrow morning, but eventually begins to meander in
response to blocking high pressure over The Canadian Maritimes.
Expect showers to develop over the south coast, Cape, Islands, and
southeastern MA overnight into tomorrow morning. Winds become
northeasterly tomorrow afternoon supporting overcast skies across
the region. High temps will be much cooler on THursday in the upper
60s to low 70s, but elevated dewpoints in the mid 60s will support a
muggy feel to the atmosphere tomorrow. Some uncertainty in how much
rainfall will accumulate, but latest HREF run supports 0.5 to 1 inch
of rain across southeastern MA and The Cape with as much as 1.5
inches over The Islands.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Not much change in the latest guidance suite compared to the past
couple of days. Broad agreement continued, but there also remained
significant uncertainty in the details. Trended 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. At the surface, southern New England should
be between two features; a large high pressure to the north, and a
low pressure approaching from the south. Ensembles showed most of
the uncertainty was more east-west in nature rather than north-
south. Thus, still have the greatest confidence in this low pressure
center passing near or just SE of the 40N/70W benchmark Thursday
night into Friday. This timing is highly uncertain, and could change
with later forecasts, even at this relatively closer time range.

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 WEDNESDAY THROUGH SUNDAY/...
Forecast Confidence Levels:

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

Through 12Z...High Confidence

LIFR ceilings and vsbys across southeastern MA and RI this
morning with areas of dense fog. Fog may reach as far north as
BOS on the east coast and may also creep up the CT River Valley
as the evening progresses. VFR at BAF/BDL deteriorating to IFR
after 08Z. VFR at BAF/ORH.

Today...High Confidence in trends, moderate on timing

LIFR ceilings/vsbys improve to VFR between 15-17Z as fog slowly
mixes out after sunrise. Winds becoming easterly by the
afternoon with shower chances increasing over the south coast by
00Z.

Tonight...High Confidence in trends

Winds become more northeasterly overnight with showers
overspreading southeastern MA, RI, and The Cape/Islands. This
will be accompanied by IFR/MVFR ceilings that will persist into
Thursday.

Tomorrow...High Confidence

Showers over southeastern MA, RI, and The Cape/Islands will
result in MVFR/IFR conditions with ceilings near 1000 feet.
Northeast winds 5 to 10 knots.

KBOS TAF...Moderate Confidence

VFR conditions may deteriorate to MVFR/LIFR as fog and low
stratus creeps up the east coast. Added a TEMPO group for 1SM
vsbys between 10 and 13Z. VFR thereafter with winds becoming
onshore by the afternoon. MVFR ceilings return overnight with
shower chances increasing Thursday morning.

KBDL TAF...High confidence in TAF.

Outlook /Thursday Night through Sunday/...

Thursday Night: Mainly VFR, with local IFR possible. Windy with
local gusts up to 30 kt. Chance SHRA.

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

Friday Night: Mainly VFR, with areas IFR possible. Breezy.
Slight chance SHRA.

Saturday: Mainly VFR, with local IFR possible. Windy with local
gusts up to 30 kt. Slight chance SHRA.

Saturday Night through Sunday: Mainly VFR, with local MVFR
possible. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Marine

Today through Tomorrow

Low-pressure approaches the coastal waters this evening and
overnight. This result in winds increasing out of the northeast into
tomorrow morning when 25+ knot wind gusts will be possible over the
coastal waters. Seas will build as well with wave heights rising to 4
to 6 feet over the outer marine zones. A small craft advisory remains
in effect for the the south coastal waters through Thursday.

Outlook /Thursday Night through Sunday/...

Thursday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Rough seas up to 8 ft. Chance of rain
showers.

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Rough seas up to 8 ft. Chance of rain showers.

Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Rough seas up to 9 ft. Slight chance of rain
showers.

Saturday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Rough seas up to 10 ft. Slight chance of
rain showers.

Saturday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Rough seas up to 10 ft. Slight chance
of rain showers.

Sunday: Moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Rough seas up to 10 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Dense Fog Advisory until 10 AM EDT this morning for MAZ013-
     016>024.
RI...Dense Fog Advisory until 10 AM EDT this morning for RIZ001>008.
MARINE...Small Craft Advisory from 8 AM to 8 PM EDT Thursday for
     ANZ232>235-237.
     Small Craft Advisory from 5 PM this afternoon to 8 PM EDT
     Thursday for ANZ254>256.

&&

$$

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