094
FXUS61 KBOX 161938
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
338 PM EDT Mon Sep 16 2024

.SYNOPSIS...
An area of high pressure over the northeast will promote
continued dry and quiet weather through Tuesday, with above
normal temperatures. The next chance for rain comes late Wednesday into
Thursday, but the best chances remain confined to Cape Cod and the
Islands.  Otherwise mainly dry with mostly cloudy conditions and
blustery NE winds through the weekend.

&&

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

Southern New England continues to remain under upper level ridging
and surface high pressure for the near-term period. On current mid-
level water vapor satellite, potential tropical cyclone eight moving
across the Carolinas. For tonight, light southerly flow under the
ridge, will support sufficient moisture return tonight in the low
levels. With dry air aloft and ample radiational cooling, expect
another shot at fog development in areas overnight. Model soundings
show shallow moisture wedged under a temperature inversion. HREF
guidance has highlighted potential for fog/low stratus for areas
across RI-southeast MA around and south of the Route 44 corridor as
well as the CT River Valley (CT, MA). Previous runs showed fog
potential for Cape Cod/Islands; however, more recent runs have
backed off on that potential. Timing-wise, there is general
agreement in areas of fog developing after midnight, continuing
through the early morning hours. One thing to add is that there
likely will be a layer of upper level clouds tonight. In some cases,
this could limit radiational cooling and limit fog formation to the
lower lying areas and south coast. Low temperatures drop into the
upper 40s to mid 50s.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...

Tuesday:

Tuesday morning, areas of fog will gradually improve through the
early morning hours. There may be lingering patchy light fog into
mid morning in spots as it slowly burns off. Remainder of the day
will be dry with warm afternoon temperatures in the upper 70s and
low 80s. Coastal areas will trend slightly cooler in the mid 70s
with onshore sea breezes developing mid-morning on the coasts.

Tuesday Night:

Tuesday night, a plume of moisture associated with the tropical
system advects northward. Cloud covers increases from south to
north. This will result in overnight low temperatures sightly warmer
than the previous couple nights in the low 50s to low 60s.

&&

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

Wed - Fri
Shortwave energy ahead of a cutoff low over the Carolinas
moves north into SNE. A weak coastal low will spin up under the
cyclonic vorticity aloft, streaming moisture into the region and
bringing our next chance for measurable precipitation. Guidance
remains relatively spread out on the potential for precip but has
generally trended drier for much of interior SNE, while the Cape and
Island stand the best chance for rain. The latest ensemble
probability for a half inch of rain from the GEFS shows 30-40% for
the Cape and Islands, while the interior is 10% or less through
Friday. Regardless of who gets rain, onshore flow will keep sky
conditions mostly cloudy to overcast through the end of the work
week, which will moderate high temperatures back into the low to mid-
70s.  Dewpoints through the end of the week stay in the low to mid-
60s, which will also help keep overnight lows mild in the low-60s.
Winds gradually increase from the ENE through Friday, becoming gusty
late Friday at 20-30mph.

Sat - Sun
Winds will continue to increase over the weekend as the
pressure gradient tightens due to being squeezed between low
pressure retreating to the south and high-pressure building from the
north.  Northeast winds are expected to gust 20-30mph, especially
near the waters.  The main impacts expected are rough seas and
strong rip currents heading into the weekend.  There could be minor
coastal flooding during multiple tide cycles starting Friday with
persistent NE flow and increasing astro tides.  Temperatures over
the weekend continue to cool into the upper 60s to low 70s with
partly cloudy skies.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
Forecast Confidence Levels:

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

18z TAF:

Today: High confidence.

VFR conditions this afternoon. Light south winds in the
interior, with seabreezes around 10 kt at BOS and at PVD.
Seabreezes become light southerly by 22-00z.

Tonight: High confidence overall, though moderate for CT-RI-
southeast MA.

VFR along and north of the Mass Pike. IFR fog and stratus are
likely to develop over the waters by early evening and then
expand northward to the Route 44 corridor in CT-RI-Southeast MA
as the night progresses. BDL, PVD, airports are most at risk
for fog/stratus but the exact timing and northward extent is
still unclear. Potential for fog/stratus for the Cape Cod
airports has decreased, so didn`t include in the TAF. Can`t
rule out the low chance these conditions make it far enough east
to impact the Cape. Light winds, calm at times.

Tuesday: High confidence.

Fog and stratus from the overnight south of the Mass Pike
gradually diminishes in the 12-15Z timeframe. VFR thereafter.
SE winds around 4-8 kt.

KBOS TAF...High confidence in TAF. VFR. SE seabreeze 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 IFR possible. Chance
SHRA.

Thursday: Mainly VFR, with local MVFR possible. Chance SHRA.

Thursday Night: VFR. Chance SHRA.

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

Friday Night: VFR. Breezy. Slight chance SHRA.

Saturday: 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.

Through Tuesday: High confidence.

High pressure over the waters will bring quiet conditions with winds
below 20 kt, varying from E to S, and seas 3 ft or less. Areas
of marine fog expected to develop over south coastal waters
tonight into early Tuesday morning, leading to reduced
visibilities.

Outlook /Wednesday Night through Saturday/...

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

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

Friday: Winds less than 25 kt. Areas of rough seas. Chance of
rain showers.

Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Rough seas up to 8 ft. 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.

&& conti with

$$

SYNOPSIS...Mensch/KP
NEAR TERM...Mensch
SHORT TERM...Mensch
LONG TERM...KP
AVIATION...Mensch/KP
MARINE...Mensch/KP