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285
FXUS62 KMHX 220743
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
343 AM EDT Sun Sep 22 2024

.SYNOPSIS...
A cold front will move south through eastern North Carolina over
the next 24 hours, with high pressure moving in behind it by
Monday. Next potential frontal system doesn`t near ENC until at
least the middle of the upcoming week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
As of 300 AM Sunday...

 - Isolated showers and thunderstorms today

The early morning surface analysis shows a weak area of low
pressure over central NC, with a warm front arcing SE into
coastal NC. A narrow area of WAA associated with this low and
warm front has been supporting a persistent area of showers and
scattered thunderstorms. This activity continues to steadily
weaken, though, thanks to weaker instability closer to the
coast. I expect this trend to continue, but there`s enough
support for a continued chance of showers for a few more hours
across southwestern sections of ENC (west of HWY 17).

To the north of ENC, another surface low and frontal boundary
has taken shape over central VA. This low, and an associated
cold front, is forecast to shift south into NC as a shortwave
moves through the Mid-Atlantic States. The front is forecast to
reach the NRN OBX by late-afternoon, with increasing low clouds
and cooling temps. Sometimes this type of setup can support a
faster frontal passage, and we`ll be watching trends through the
day. Along and ahead of that front, daytime heating of a
modestly moist boundary layer should support MLCAPE up to around
1000j/kg by this afternoon, especially across southwestern
sections of ENC. This will be occurring as large-scale
subsidence develops on the backside of the departing Mid-
Atlantic shortwave. An area of mid-level drying is forecast
during this time as well. Despite the favorable timing of the
front with peak heating, I expect the subsidence and drier air
to limit the coverage of convection this afternoon. It may even
be a scenario where we see isolated showers, and not much of a
thunderstorm threat. It should be noted that deep layer shear
around 30kt could support a stronger thunderstorm, but because
of the limitations to deeper convection, I am not expecting a
severe weather risk today.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
-- Changed Discussion --
As of 300 AM Sunday...

 - Turning a bit cooler tonight

A cold front is forecast to slide south through ENC this
evening and tonight, bringing lower dewpoints and cooler
temperatures. Guidance differs on how much cloudcover will
accompany the front, which leads to differences in how cool it
will get tonight. For now, I kept lows in the low to mid 60s,
with the expectation that skies will be partly to mostly cloudy.
Should clouds be less prevalent than forecast, some inland
areas could see lows in the upper 50s. I expect there will be
enough mixing with the front tonight to limit the fog potential.
-- End Changed Discussion --

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 330 PM Saturday...A slight chance of showers Sunday, then
ridging starts building in from the north as a low spins up
offshore to our northeast, gradually shifting further offshore
to our east. Seasonable temps through the period and dry Monday-
Tuesday evening. Rain chances increase mid to late week as
ridging could weaken and a low treks across the Ohio Valley and
Great Lakes region.

Monday-Tuesday:
Low offshore could produce high swell 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, keeping
us dry Monday and Tuesday. Seasonable temps with highs in the
low 80s inland, upper 70s to near 80 for beaches.

Wednesday-Friday:
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 next week. 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 /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through 06z Monday/...
As of 130 AM Sunday...

 - Sub VFR CIGs possible at times over the next 24 hrs (30-50%
   chance)

Weakening SHRA and TSRA, associated with a weak surface low and
warm front, will continue to push south through central NC over
the next several hours. These SHRA may clip far western
sections of ENC, and I`ve continued to advertise this potential
at KOAJ, KISO, and KPGV. It appears the greatest TSRA risk
overnight will remain just to the west of ENC. Close to sunrise
Sunday morning, recent short-term guidance suggests there may be
a renewed area of SCT SHRA that develops across portions of
ENC. Confidence in this is low, so no mention in the TAFs for
now. During the day Sunday, a cold front will move south through
the area. Despite drying conditions aloft, there may be just
enough lift, moisture, and instability to produce isolated SHRA
and TSRA. Because of the expected low coverage, I`ll hold off on
introducing any SHRA or TSRA mention yet in the TAFs. Behind
the front, a cooling and moistening northeasterly flow may lead
to a period of sub-VFR CIGs.

LONG TERM /Sunday night through Thursday/...
As of 4 AM Saturday...Pred VFR conditions expected through the
long term.

&&

.MARINE...
-- Changed Discussion --
SHORT TERM /Through Sunday/...
As of 300 AM Sunday...

 - Elevated seas continue across the central and northern
   coastal waters

 - Cold front to bring a northeasterly wind shift late today
   into tonight

Light southerly winds of 5-10kt are expected for much of the
day across most waters today. By late this afternoon, and
especially this evening, a cold front will push south through
area waters, and will be accompanied by northeasterly winds
building to 10-20kt. For now, winds are expected to remain below
25kt with this northeasterly wind surge, but we`ll monitor
trends in obs upstream, and in model guidance, in case this risk
were to increase. For the central and northern coastal waters,
seas remain elevated in the 4-6 ft range. A longer period swell
of 5-7ft at 11 seconds is forecast to arrive this evening and
tonight thanks to low pressure off the New England Coast. In
light of this, we`ll continua the SCAs for coastal waters north
of Ocracoke Inlet. A few showers and thunderstorms may
accompany the front later today and tonight, but widespread
thunderstorm activity is not expected.

LONG TERM /Sunday night through Thursday/...
As of 415 AM Saturday...SCA In Effect through 6Z Tuesday for
coastal waters north of Ocracoke.

Sustained variable winds around 10 kt Sunday with ridging
building in, then around 15 kt Monday before dropping back down
to 5-10 kt and veering to become more easterly Tuesday and
Wednesday. SCA in effect for waters north of Ocracoke Inlet as
waves greater than or equal to 6 ft are expected from the low
offshore through early next week. Seas will be 2-6 ft Sunday,
and 2-7 ft Monday/Tuesday before dropping down to 2-6 ft
Wednesday the low offshore and somewhat gusty winds result in
higher swell. Waters off Crystal Coast and coastal Onslow will
be a bit protected from the more easterly swell courtesy of Cape
Lookout, and will be on the lower end of these wave height
ranges. OBX (particularly north of Hatteras) and the Gulf Stream
will not be protected and will see the higher values in the
ranges above.
-- End Changed Discussion --

&&

.TIDES/COASTAL FLOODING...
As of 330 PM Sat... No real changes to the forecast thinking as
coastal flooding will continue to be a threat given the higher
than normal astronomical tide cycle through this weekend and
into Monday during high tide each day. Coastal Flood Advisories
remain in effect for all oceanside coastal areas into Monday
evenings high tide. Increased swell from a low offshore may
bring minor overwash concerns Tuesday and into midweek for the
OBX north of Cape Hatteras, although recent guidance has backed
off some on the strength of this offshore low, which may lessen
the risk of coastal impacts.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
NC...Coastal Flood Advisory until 2 AM EDT Tuesday for NCZ195-196-
     199-203>205.
     Beach Hazards Statement from 8 AM EDT this morning through
     this evening for NCZ203-205.
MARINE...Small Craft Advisory until 8 AM EDT Wednesday for AMZ150-152-
     154.
-- End Changed Discussion --

&&

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