221
FXUS62 KMHX 161747
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
147 PM EDT Mon Sep 16 2024

.SYNOPSIS...
An area of low pressure to our south will slowly strengthen
today as it drifts northwards towards the southern NC coast.
There is potential that this low becomes a Tropical Storm
today before it makes landfall. Troughing will remain over the
Eastern Seaboard through next week as well keeping unsettled
conditions across ENC.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 10:25 AM Mon...There are no major changes to the forecast
with the mid-morning update.

Primary forecast focus this morning continues to be Potential
Tropical Cyclone #8, currently about 160 miles SSW of Cape
Lookout. The system itself has moved little this morning, stuck
in weak steering currents south of a sprawling mid-level ridge
over New England that has moved little over the past several
days. The system will gradually gain speed to the northwest
today as it gets picked up by the upper ridge, and the center is
forecast to cross inland over northeastern SC this afternoon.

Regardless of whether the system is tropical or not, the
expected impacts for eastern NC have changed little from the
previous forecast. Impacts from PTC 8 are already beginning as
its associated rain showers approach the Crystal Coast, expected
to steadily encroach northward as the low drifts towards the
coast. Winds continue to slowly climb and will peak by early
this afternoon. The hazards with this system are multifaceted
and include:

- Flash Flooding: Very heavy rainfall will fall from this storm
  as PWATs soar to 2-2.25" today. The forecast axis of heaviest
  rainfall, per the 00z guidance suite, has shifted slightly
  westward and is now focused over Cape Fear and far
  northeastern SC. Consequently, storm total rainfall has
  trended down modestly for ENC with an area-wide 2-3 inches,
  while south and west of Highway 70 3-6 inches with isolated
  higher amounts are forecast. This aspect of the forecast
  remains fluid as uncertainty over track and intensity
  lingers, and for that reason a broad Flood Watch is being
  maintained for the entire FA. Highest likelihood for flooding
  issues remains focused south of Highway 70.

- Coastal Flooding: The coastal flooding threat remains largely
  unchanged from yesterday, with the potential for up to 3 feet
  of water AGL in low lying areas. See the TIDES/COASTAL FLOOD
  section for more details.

- Tornadoes: The current forecast track of PTC 8 over
  northeastern SC brings the tornado-favorable right front
  quadrant across eastern NC. The highest low level helicity
  will be displaced to our west, along the I-95 corridor, but
  0-3 km SRH of 100-250 m2/s2 combined with afternoon CAPEs
  between 500-1000 J/kg support at least an isolated risk of a
  brief tornado especially this afternoon and early evening.

- Strong Winds: Winds will strengthen to 30-40 mph along the
  coast today, especially south of Ocracoke Island. Sporadic
  wind gusts up to 50 mph are possible in passing rain bands.
  These may cause sporadic power outages and/or tree damage.

Clouds and rainfall will keep temperatures flat and below
average for mid-September, with highs in the low to mid 70s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
As of 400 AM Mon...The surface low will continue to accelerate
northwestward overnight into Tuesday morning around the
periphery of the upper ridge. Guidance shows the system will
begin to entrain some drier air over inland areas with deeper
moisture focused over the Outer Banks, and this is where the
band of heavier precipitation will be focused for the overnight
hours. Total rainfall overnight will range between 1-3 inches
posing a marginal flooding risk. Winds will drop off quickly
through the evening as the pressure gradient weakens behind the
low.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 400 AM Mon... Eastern North Carolina will remain
unsettled through the entire period as an impactful low moves
out of the area Tuesday. Beyond that, troughing over the Eastern
Seaboard will continue to bring daily chances for showers and
thunderstorms across the region into next weekend.

Tuesday...The low lifts further inland tomorrow, eventually
lifting north of the region by Tue afternoon allowing for much
more benign weather to finally begin to overspread ENC although
shower activity is likely to linger across OBX through the day.
Expecting below avg temps across ENC with highs only getting
into the 70s to low 80s while lows get down into the 60s to low
70s.

Wednesday into the weekend... Previously mentioned upper trough
will remain over the Eastern Seaboard through the end of the
week while at the surface previously mentioned low is forecast
to be to the north and likely dissipated. As we get into the
weekend, there remains uncertainty with the forecast as the
upper trough over the Eastern Seaboard is forecast to cutoff
into an upper low as upper ridging builds across the Northeast.
As is typical with upper lows, spread in timing and depth of
the feature remains large and forecast confidence remains below
average.

Either way, daily chances for showers and thunderstorms will
remain possible across ENC into the weekend as favorable
troughing remains overhead. Continued onshore flow will keep
clouds around the region while temps remain at or below avg.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
SHORT TERM /through 18z Tues/...
As of 1 PM Monday...Periods of sub-optimal flight conditions
can be expected through the TAF period as Potential Tropical
Cyclone #8 moves onshore. Heavy rain bands moving across the
area will produce decreased ceilings, visibility, and strong
wind gusts up to 30 kt. Prevailing MVFR ceilings, with periods
of IFR during heavier rainfall, are expected through midnight.
Late tonight/early tomorrow morning, IFR ceilings become more
probable. As the low moves inland and weakens, winds will
decrease but remain breezy with gusts around 15-20 kt.
Prevailing IFR conditions should linger through mid-morning
before improving in the early afternoon as rain chances decrease
and ceilings lift.

LONG TERM /Tuesday through Friday/...
As of 405 AM Mon...Continued unsettled weather will bring a
chance for sub-VFR conditions across ENC tomorrow as a low
pressure system moves out of the area. After the low moves to
the north we will still see at least a low end threat for the
rest of the week for sub- VFR conditions as daily chances for
afternoon and evening showers and thunderstorms will remain.

&&

.MARINE...
SHORT TERM /Today and Tonight/...
As of 410 AM Mon...Dangerous boating conditions ongoing this
morning as winds remain strong on the northern periphery of an
area of elongated low pressure a couple hundred miles south of
Cape Lookout. This low may become a Tropical Storm later today,
and NHC is continuing advisories on it as PTC (Potential
Tropical Cyclone) #8. Regional observations show northeasterly
winds of 15-25 kt, with seas ranging 8-12 feet.

Little change was made in the forecast. Strongest winds will be
focused over Onslow Bay and southern Raleigh Bay this morning
and afternoon with gusts up to 35-40 kt. Farther north, forecast
winds have decreased slightly but still peak at 20-25 kts with a
few gusts up to 30 kt. Winds will likely peak this afternoon,
then subside as the low shifts onshore and fills. Seas will
continue to be quite hazardous today, peaking at 10-15 ft.
Conditions begin to slowly improve into Tues morning.

LONG TERM /Tuesday through Friday/...
As of 415 AM Mon...Dangerous marine conditions continue into
Tuesday, but gradually improve from south to north with winds
easing down to 15-20 kts with gusts up around 20-25 kts by Tue
morning and veering to a SE and eventually SW direction while
seas fall down to 5-8 ft along our coastal waters. Winds and
seas fall even further Wed with winds remaining S`rly at 10-15
kts while seas along our coastal waters finally lower down to
3-5 ft by Wed morning. This should then end SCA criteria across
all waters with more benign boating conditions forecast for
Thurs. Daily chances for showers and thunderstorms will remain
possible through the period with locally enhanced winds and seas
possible within the strongest storms that may develop.

&&

.HYDROLOGY...
As of 415 AM Mon...Widespread heavy rain is expected late
today through tomorrow as poorly organized low pressure
drifts northwestward towards the coast of South Carolina.
Abundant tropical moisture with this system will lead to
extremely heavy rainfall rates over areas that have become
saturated over the last week. Where the heaviest rainfall sets
up remains uncertain due to larger than average spread in model
guidance, but confidence in heaviest rainfall remains highest
along and south of US 70 where storm total 3-6 inches of rain
is possible. Higher isolated totals are possible in stronger
rainbands. A more widespread 2-3 inches is forecast for the
rest of ENC.

&&

.TIDES/COASTAL FLOODING...
As of 420 AM Mon...There will be potential for coastal flooding
of up to 1-3 ft AGL today as winds slowly strengthen in
association with a poorly organized low pressure system to our
south over the Gulf Stream which has the potential to become a
Tropical Storm later today. Additionally, coastal flooding may
be worsened due to the astronomically high tide cycle we are
entering.

Ahead of this system, strong ENE/E winds will buildup water
along the SE portion of the Pamlico Sound as well as the Neuse,
Bay, and Pamlico Rivers. Oceanside, high water levels in
addition to strong wave run up will likely produce ocean
overwash along NC 12 on the Outer Banks at times of high tide.

Additionally with this system we can expect a high threat of
rip currents, rough and dangerous surf/shore break, and beach
erosion.

Current Coastal Flood and High Surf headlines are in good shape,
and no changes were made for this morning`s forecast package.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Tropical Storm Warning for NCZ195-196-199.
     Flood Watch through Tuesday afternoon for NCZ029-044>047-
     079>081-203>205.
     Coastal Flood Advisory until 8 AM EDT Tuesday for NCZ080-094-
     194>196-199.
     Flood Watch through Tuesday morning for NCZ090>092-094-193>196-
     198-199.
     Beach Hazards Statement until 8 PM EDT this evening for NCZ195-
     196-199-203>205.
     High Surf Advisory until 8 AM EDT Tuesday for NCZ195-196-199-
     203>205.
     Coastal Flood Advisory until 11 PM EDT this evening for
     NCZ203>205.
MARINE...Small Craft Advisory until 8 AM EDT Tuesday for AMZ131-135>137-
     230-231.
     Small Craft Advisory until 8 AM EDT Wednesday for AMZ150-152.
     Tropical Storm Warning for AMZ154-156-158.
&&

$$
SYNOPSIS...MHX
NEAR TERM...MS/OJC
SHORT TERM...MS
LONG TERM...MS
AVIATION...OJC/MS
MARINE...MS
HYDROLOGY...MHX
TIDES/COASTAL FLOODING...MHX