292
FXUS62 KMHX 150229
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1029 PM EDT Wed Aug 14 2024

.SYNOPSIS...
High pressure building in from the north will remain over the
eastern seaboard through late week before a front begins to
approach from the west this weekend bringing increasing
precipitation chances across the area. Swells from distant
Tropical Storm Ernesto will begin impacting the coast starting
Friday and persisting into the weekend, bringing a threat for
elevated rip current risk and coastal impacts.

&&

.NEAR TERM /OVERNIGHT/...
As of 915 PM Wednesday...

 - Monitoring fog potential overnight

Clouds have been a bit slower to move out than previously
forecast, and this has slowed the diurnal drop in temps.
However, where skies have cleared, good radiational cooling
conditions have allowed temps to drop quickly, so the forecast
lows tonight still look solid. The fog potential still remains
uncertain. Probabilistic guidance continues to show a low chance
(10%) of fog development, but with good radiational cooling
conditions developing, T/Td spreads are quickly lowering. At
face value, I suspect this will lead to areas of shallow fog, at
minimum. For now, we`ll continue to keep a mention of patchy
fog in the forecast, and continue to monitor trends in case
something more impactful becomes more evident.

PREVIOUS FORECAST...Shortwave pushes off the coast overnight
with any lingering precipitation quickly falling off after
sunset. Skies will quickly clear, and with calm winds tonight
looks like a good radiational cooling event. Followed the prior
shift`s lead and kept lows at the bottom of the guidance
envelope (low to mid 60s, around 70 along the coast). Guidance
soundings depict a very shallow but saturated boundary layer,
and fog remains a risk early Thurs morn. The overall
probabilities of lower visibilities are low (under 20%), but the
conditional risk of dense fog is elevated. Maintained fog
mention from the previous forecast, but this will be need to be
closely monitored in future updates.

&&

.SHORT TERM /THURSDAY/...
As of 320 PM Wednesday...Yet another nice day as high pressure
continues to linger overhead. Even drier air will seep into the
area as forecast PWATs plunge below an inch and dew points fall
into the upper 50s as mixing is maximized in the afternoon. A
minority of guidance is showing a few spotty showers developing
across NOBX as a weak shortwave pivots around the departing
upper trough, but given such dry forecast conditions did not put
in any PoPs for the period. Highs perhaps a degree higher than
today, but still near to slightly below average - mid to upper
80s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
As of 330 AM Wednesday...A drying trend will commence mid-week
as a cold front offshore slowly sags southward and high pressure
builds into the area from the northwest.

The upper trough shifts off the East Coast Thursday and Friday
with upper ridging building in from the west. NHC guidance
continues to take Tropical Cyclone Ernesto well off the NC
coast, close to Bermuda, Friday night through the weekend. At
the same time, another trough will dig south from the Great
Lakes into the eastern CONUS, with a weak frontal feature moving
into Eastern NC by late weekend, bringing with it increasing
chances for showers & thunderstorms across the region. Trended
PoPs closer to climo, diurnally-driven convective activity by
midday through the evening with waning activity overnight. 00Z
14th guidance is in better agreement with a surface boundary
shifting more offshore by Monday, so may need to trim back PoPs
a bit, esp. for inland locations. Seasonable temps continue with
highs generally in the mid 80s through Tuesday.

While we are not expecting direct impacts from Ernesto at this
time, large swells are expected to impact the beaches bringing
an increased rip current risk and large surf beginning Friday
and continuing through the weekend. See Coastal Flooding section
below for more details.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
SHORT TERM /Through 00z Friday/...
As of 630 PM Wednesday...

 - Monitoring BR/FG/MIFG potential overnight

A couple of weak surface boundaries will continue to support a
few pop-up SHRA through around 00z/8pm, then there should be a
quick decrease with the loss of daytime heating. The main
challenge overnight will be BR/FG/MIFG potential. Reaching the
crossover temps (low to mid 60s) is plausible, and I expect
this, alone, will at least support a risk of MIFG. However, the
risk of a deep/more substantial FG risk appears more
questionable due to a drier low- level airmass working south
into the area. Probabilistic guidance hints at the potential for
LIFR VIS in BR/FG, but only gives about a 10% chance. The
previous TAFs had a sub-VFR BR mention in. Given all of the
above, I don`t see any reason to deviate from this for now (ie.
towards something more impactful). Something to monitor in
observations and forecasts through the night, though...

LONG TERM /Thursday night through Monday/...
As of 330 AM Wednesday...Dry weather expected Thursday and
Friday, then unsettled weather returns for the weekend. Light
winds and good radiational cooling conditions will continue to
bring the chance for late night/early morning fog and stratus
most mornings, especially given the saturated ground. Weak cool
front will move into the area by this weekend, yielding
increasing chances for unsettled weather with showers/storms
possible, mainly during peak heating which may produce sub-VFR
conditions at times on Saturday and Sunday.

&&

.MARINE...
SHORT TERM /through Thursday/...
As of 325 PM Wed...Benign boating conditions continue across
our waters with high pressure remaining still firmly in control.
Regional observations show north to northeasterly winds of 5-10
kt with seas around 2-3 feet, and little change in these
conditions are expected until Thursday night when swell from
distant TC Ernesto begins to creep into area waters. Widespread
5-15 kt N-NE winds are forecast across all waters and 2-3 ft
seas are forecast across all coastal waters through the period.

LONG TERM /Thursday night through Monday/...
As of 335 AM Wednesday...Good boating conditions through much
early Friday morning with high pressure building into the area
bringing NE winds around 5-15 kt. Winds begin to veer to E and
SE late Friday into Saturday as the high moves offshore, and
Tropical Cyclone Ernesto passes close to Bermuda. Seas will
generally be around 2 to 3 ft through early Friday. By sunrise
Friday, we will begin to see long period (14-15 second) swells
from Ernesto move into the waters which will build through
Saturday. Wave guidance suggests long period swells could impact
the waters through Sunday into early Monday. Long period swells
could make inlet conditions particularly dangerous at times of
opposing winds/currents/tides and perpendicular swell energy
(SE/E/NE direction), especially for southeast and east facing
inlets along the NC coast.

&&

.HYDROLOGY...
As of 325 PM Wed...A few more rivers have fallen below flood
stage, but overall synopsis has not changed. River flooding
will continue across many river basins in Eastern NC, including
the Trent, Neuse, and Tar Rivers as well as several tributaries.
River flooding will persist through the weekend and into next
week as the abundant rainfall that occurred across the NC
Piedmont, upstream of the forecast area, makes its way towards
the sounds and coast. It should be noted that some of the worst
river flooding is still yet to come, with some rivers not
cresting until late week or this weekend.

&&

.TIDES/COASTAL FLOODING...
As of 330 PM Wed...Little change in the forecast over the next
few days as TC Ernesto is forecast to strengthen into a
hurricane later today then pass well to the east late week into
this weekend. Strong long period swells from distant Ernesto
will combine with high astronomical tides, which will likely
lead to several coastal hazards. Dangerous rip currents and
rough surf are expected for the beaches. There is also potential
for beach erosion and ocean overwash (esp. where dune structures
are vulnerable). The greatest window of concern will be Friday
morning into early next week. More specifics will be provided
over the next few days.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.

&&

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