460
FXUS62 KMHX 231950
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
350 PM EDT Mon Sep 23 2024

.SYNOPSIS...
High pressure will remain anchored to the north through midweek as a
warm front approaches eastern North Carolina from the west and
stalls. More unsettled weather is possible by week`s end.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 345 PM Mon...Very pleasant day ongoing across eastern
North Carolina as a narrow wedge of high pressure extends
between a low well off the coast of the Atlantic and a warm
front marking the edge of a weak CAD wedge. A pool of low-level
dry air has kept skies mainly clear today and allowed
temperatures to climb into the low 80s, but cloud cover will
gradually increase as the warm front and its associated moisture
shift eastward. A few spotty showers may pop ahead of the front
early Tue morning, but with the deeper moisture to the west and
lack of appreciable upper support activity will be weak.

Clear skies and light winds hold on longest across the Outer
Banks where we could see some radiational cooling with lows into
the low 60s, but farther inland with increasing low clouds
temperatures will hover in the mid to upper 60s.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
As of 345 PM Mon...Low levels continue to gradually moisten
tomorrow as 850 mb flow turns southwesterly and surface winds
veer further to the east and south as the warm front pushes
farther east. How far the boundary makes it towards the coast
remains uncertain, but CAMs do point to the front being a focal
point for isolated shower and thunderstorm development as CAPEs
climb to 500+ J/kg, especially west of Highway 17. Persistent
ridging aloft will keep coverage limited, but with 30-35 kt of
0-6km shear a stronger storm is not out of the question.

Despite increasing low-level thicknesses, plenty of cloud cover
will keep temperatures close to today`s observed highs in the
upper 70s to low 80s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 200 AM Monday...

 - Above normal temperatures mid-week

 - Watching the tropics late-week

Synoptic Summary: Upper level ridging is forecast to remain in place
across the Southeast U.S. through mid-week, then shift offshore as
an upper level low drops south into the Mid-south. The evolution of
those two upper level features will play a significant role in the
potential tropical system that is forecast to move into the eastern
Gulf of Mexico later this week. Over the weekend, ridging may
attempt to move back over the coastal Southeast U.S.

Tuesday-Wednesday: Low-level thicknesses are forecast to increase
beneath ridging aloft, supporting above normal temperatures,
especially by Wednesday. A few locations may flirt with record warm
lows during this time. For reference, normal highs for late
September are in the low 80s. Ridging plus drying aloft should
lead to a lower risk of convection on Wednesday.

Thursday-Saturday: The focus during this period will be the track of
the potential tropical system in the Gulf of Mexico. The recent
suite of 12z/00z guidance has become much more aligned with an
inland track through the Southeast U.S. In general, this puts ENC on
the moist, easterly side of the system, but also removed from the
higher-end wind impacts. This all changes, of course, if the track
shifts east. Of note, with ridging situated just offshore, there may
be a sharp gradient in rainfall on the edge of the system. For now,
the key message with this system is to be aware of the potential,
and to stay tuned to forecast updates through the week.

Sunday-Monday: In the wake of the late-week system, a cold front may
try to slide SW off the Atlantic, and across ENC over the weekend.
While this would tend to bring cooler weather with it, it may also
bring another potential for showers and thunderstorms.

Monday-Tuesday:
High astronomical tides will be impacting OBX beaches Monday-
Tuesday. See TIDES/COASTAL FLOODING section for more
information.

High pressure centered over Maine and the Canadian Maritimes
has a ridge extending south over much of the east coast at the
surface, keeping us dry Monday and Tuesday. Further aloft a high
is centered to our south paired with lows to our west and east
put us in a weak omega block setup allowing the high to linger.
Seasonable temps with highs in the low 80s inland, upper 70s to
near 80 for beaches.

Wednesday-Saturday:
Uncertainty increases a lot towards the middle and end of next
week, as multiple synoptic features will be at play and slight
deviations result in large changes with the forecast. While
ridging continues to spread over ENC from the north Wednesday, a
low pressure system forecasted to be over the Great Lakes will
have a cold front trailing from it extending down to the Gulf
coast. This cold front could stall to our west due to the
ridging over us, or the ridge weakens and gives way to the low,
or the front sweeps north of us around the high. In addition to
the parent low over the Great Lakes and ridge overhead, we will
be keeping an eye on a tropical system that could initiate in
the Gulf Coast within 7 days. It is too soon to determine what
impacts, if any, we receive in ENC should this cyclone form. Due
to all this uncertainty, I opted to keep PoPs at Chc/Schc for
now through the remainder of the long term as a higher moisture
advection regime is more supportive of rain at the end of the
period.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SHORT TERM /through 18Z Tuesday/...
As of 130 PM Mon...VFR conditions across all eastern NC
terminals this afternoon as weak high pressure ridges in from
the north. Plenty of MVFR and IFR to our west ahead of a warm
front, but a low- level dry air intrusion from the northeast is
keeping conditions SKC thus far. Expect clouds to gradually
increase through the night as the front shifts eastward, and
there is a moderate risk (50-60%) chance of MVFR cigs for the
coastal plain after 06z Tue, lingering into Tues AM as pre-
frontal moisture continues to increase. A few iso showers and an
odd storm or two have a low chance (20-30%) of impacting
PGV/ISO/OAJ by the end of the TAF period. Increase in clouds
precludes a fog threat overnight.

LONG TERM /Tue through Fri/...
As of 200 AM Monday...

 - TSRA possible Tuesday (20-30% chance)

 - Watching the tropics late-week

Isolated to scattered SHRA and TSRA will be possible on Tuesday,
followed by a decreased risk on Wednesday. The chance of SHRA and
TSRA may then increase late week on the outer edges of a potential
tropical system moving inland through the Southeast U.S. Stay tuned
for updates on what impact this system may have to aviation late in
the week.

&&

.MARINE...
SHORT TERM /Through Tuesday/...
As of 345 PM Mon...Rough conditions persist over the waters
north of Cape Hatteras this afternoon as persistent
northeasterly swell continues to radiate off lingering low
pressure several hundred miles east of the Carolinas. Seas here
are 5-7 feet, while south of Hatteras seas are closer to 2-4
feet. Northeasterly winds have eased slightly, now at around 10
kt.

Little change is expected in the short term, although winds will
veer more east to southeasterly tomorrow as a weak warm front
approaches from the west. The low offshore will begin to depart
farther offshore on Tuesday, allowing swell to subside modestly but
still remaining at 6+ for waters beyond 10 nm.

Existing SCA in the near term remain in good shape, and no changes
were made to the headlines this afternoon.

LONG TERM /Tue through Fri/...
As of 200 AM Monday...

 - Elevated seas on Tuesday

 - Renewed risk of elevated winds and seas late-week

 - Watching the tropics late-week

High pressure offshore, plus a weak gradient, is forecast to keep
winds light (5-10kt) through mid-week. Despite the light winds,
northeasterly long-period swell will continue to impact the central
and northern coastal waters with 5-7 ft seas through at least
Tuesday night. After a brief reprieve, another period of elevated
winds and seas appears increasingly likely as a potential tropical
system moves inland through the Southeast U.S. Stay tuned for
updates on this system and what impact it will have on the ENC
waters.

&&

.TIDES/COASTAL FLOODING...
As of 350 PM Mon...The coastal flood threat continues for all
of coastal North Carolina for another day as tide levels remain
elevated. Water levels at high tide tomorrow will be slightly
lower Tuesday than today, but could still result in up to a foot
of inundation above ground level. Along and north of Ocracoke,
persistent northeasterly swell from a distant low offshore will
continue to bring minor overwash concerns with maximum
inundation around 1-2 feet. No changes were made to existing
Coastal Flood headlines this afternoon.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory until 5 PM EDT Tuesday for NCZ195-196-
     199-203>205.
     Beach Hazards Statement until 8 PM EDT this evening for NCZ203-
     205.
MARINE...Small Craft Advisory until 8 PM EDT Wednesday for AMZ150-152-
     154.

&&

$$
SYNOPSIS...MHX
NEAR TERM...MS
SHORT TERM...MS
LONG TERM...RM/RCF
AVIATION...RM/MS/RCF
MARINE...RM/MS/RCF
TIDES/COASTAL FLOODING...MHX