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386
FXUS62 KMHX 201942
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
342 PM EDT Thu Jun 20 2024

.SYNOPSIS...
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High pressure continues to extend across the Carolinas with weak
coastal troughing in place through tomorrow. This may bring
some showers to the region into the weekend. A steady increase
in heat and humidity is expected over the next several days with
"feels like" temperatures potentially reaching the triple
digits on Sunday. The next chance for much needed appreciable
rain comes early next week with a frontal passage.
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&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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As of 320 PM Thu...Mid-level ridge remains in place over much
of the eastern CONUS this afternoon as expansive Atlantic high
pressure continues to ridge over the Carolinas like the past few
days. Main difference in the pattern today is a weak tropical
wave just north of the Bahamas, which is forecast to drift
towards and eventually across the far southeastern coast.
Eastern NC won`t feel any direct impacts from this wave, but it
will serve as a source for deeper moisture to makes it way into
the area into the weekend.

Another dry and cloudless night is on tap for tonight. Given the
persistent easterly flow, however, low-level moisture continues
to deepen and with a radiational cooling set up some patchy fog
is probable in the pre-dawn hours. Best signal for formation is
west of Highway 17, but shallow low-impact fog is possible
anywhere in well sheltered locations. Lows tonight will be
similar to yesterday, in the mid to upper 60s inland and low 70s
along the coast.
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&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
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As of 345 PM Thu...Coastal trough will gradually sharpen
offshore as aforementioned tropical wave shifts toward coastal
GA/FL in the morning. With the deeper moisture advection, the
trough will provide a focal point for shower develop and likely
a few thunderstorms given ample instability offshore thanks to
warm SSTs. Hi-res guidance continues to favor some of this
activity penetrating inland, mainly along the Crystal Coast and
the Outer Banks from Cape Hatteras south, and maintained
mentionable PoPs for these areas from the previous forecast. A
second round of convection is possible along the sea breeze in
the afternoon. Farther inland, high pressure and subsidence
aloft will stubbornly remain in place maintaining hot and dry
conditions. Here, highs will climb into the low 90s but dew
points will make a run towards the low 60s. Along the coast,
highs settle in the upper 80s but dew points will climb well
into the upper 60s to potentially 70 along the immediate coast.
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&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
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As of 315 AM Thursday...

 - Still watching the SW Atlantic

 - Increased risk of heat impacts late-weekend into next week

 - Increased risk of thunderstorms next week

Synoptic Summary: Persistent, and anomalous, ridging aloft over the
Eastern U.S. is forecast to finally break down by this weekend, with
broad troughing continuing into next week. At the SFC, low pressure
is forecast to move across the SW Atlantic and towards the FL/GA
coast on Friday, with coastal troughing developing north through the
coast of the Carolinas. Broad surface troughing is then forecast to
develop across the Eastern U.S. over the weekend, and last into next
week. A front, or two, may attempt to make a run at ENC next
week.

Saturday-Sunday: High pressure shifting further east out into the
Atlantic will allow a warming, and moistening, southerly flow to
develop over the weekend. Despite the increasing moisture, it
doesn`t look like the chance of precip will immediately respond,
mainly due to a lack of better instability. At minimum, though, it
looks like a few showers or storms may develop on the seabreeze both
days. The bigger story over the weekend will be the building heat.
With the southerly flow developing, we`ll lose the "cooler" easterly
flow of late that has helped keep temps and humidity at more
comfortable levels. Both deterministic and ensemble guidance
continue to show a good signal for heat-related impacts, especially
on Sunday, as heat indices ("feels like" temps) reach 100-105
degrees. Sunday could be our first opportunity for heat headlines if
recent trends hold.

Monday-Thursday: Humidity will continue to increase next week with a
continued southerly flow off the Gulf of Mexico and western
Atlantic. With increasing low-level thicknesses, the heat and
humidity combination is expected to lead to a continued risk of heat-
related impacts. The risk of thunderstorms will be increasing during
this time as well, though, which will have a daily impact on where
the greatest risk of dangerous heat will be. Bottom line, there
continues to be a good signal for multiple days of an elevated to
significant heat risk for much of the area.

Regarding the thunderstorm risk, Monday continues to be the day
favored for the highest chance, and is also the next appreciable
chance of wetting rainfall to help offset the recent stretch of dry
weather. Guidance differs on the timing of a couple of fronts that
may attempt to move into the area, which of course factors into
where the greatest coverage of thunderstorms will be. Also of note,
some guidance hint at the remnants of the SW Atlantic wave getting
pulled northeast through the area. If this were to occur, this would
support an increased risk of precip. Lastly, the shear/instability
combo still appears supportive of a marginal severe weather risk on
Monday, and that will be something to watch in the coming days.
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&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SHORT TERM /through 18Z Friday/...
As of 130 PM Thu...VFR conditions prevail across all terminals
this afternoon as offshore high continues to extend over the
Carolinas for yet another day. Scattered to broken cu field will
continue through daytime hours with the probability of any
rainfall under 10% this afternoon. Main focus turns to tonight,
primarily along the coastal plain, where clear skies, calm
winds, and increasing low-level moisture provide a favorable set
up for some patchy fog early Fri AM. Introduced MVFR cigs at PGV
and ISO for this risk.

Moving into Friday, increasing clouds and moisture from the
south as weak tropical wave/low, currently just north of the
Bahamas, migrates across the far southeastern coast tomorrow
morning. The increase in moisture will feed an uptick in
offshore showers and a few thunderstorms, which could drift
along the immediate coast tomorrow morning. Afternoon sea breeze
circulation could also spark convection in the early afternoon.
Signal right now keeps any MVFR cigs from penetrating more than
a few miles inland, but can see a low-end risk for EWN/OAJ if
moisture intrudes farther than forecast.

As of 7 AM Thursday...VFR
conditions persist. Some 35kft ceilings are still scattered
across the CWA but will lift soon and make way for diurnal cu
this afternoon. A better fog setup will be in place tonight
given an increase in moisture, clear skies, and decoupling
winds. Confidence was not high enough to include mention of fog
in the TAFs at this time, but the best chance would be across
western terminals (PGV, ISO, and OAJ).

LONG TERM /Thursday night through Monday/...
As of 315 AM Thursday...

 - Increased risk of TSRA and sub-VFR conditions Monday

A developing coastal trough may support low CIGs and SHRA/TSRA along
the immediate coast Friday. This will be followed by isolated SHRA
and TSRA developing each day along the seabreeze over the weekend. A
better chance of TSRA and sub-VFR conditions is still expected
Monday. A period of breeze southwesterly winds is expected Sunday
into Monday as well, with non-TSRA gusts of 20-25kt possible.

&&

.MARINE...
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SHORT TERM /through Friday/...
As of 345 PM Thu...Swell from a weak tropical wave just north of
the Bahamas this afternoon continues to encroach into our
offshore waters, mainly south of Cape Hatteras, where seas have
climbed to around 5-6 feet (with a few 7 foot observations
across far Onslow Bay). High pressure remains in control with
another day of easterly flow around 10-15 kt. The tropical wave
is forecast to drift inland near the FL/GA border tomorrow
morning, and this afternoon`s swell will gradually abate through
the evening. SCAs remain for the waters south of Ocracoke Inlet,
but all others were dropped this cycle with waves reaching only
4 to 5 feet.

Another benign day of boating conditions returns tomorrow, with
winds gradually veering more southerly through the day as the
surface high finally begins to move further offshore. Winds will
generally be no higher than 10 kt and seas will be able to
return back to around 4 feet, except 3 feet closer to shore.

LONG TERM /Thursday night through Monday/...
As of 315 AM Thursday...

 - Elevated wind and seas Monday

 - Increased thunderstorm risk on Monday

Elevated seas from today will begin to slow lay down on Friday as
the persistent easterly flow of late begins to subside. Weaker flow
continues into Saturday, with south winds of 5-15kt common. That
southerly flow will notably increase to 15-25kt Sunday into Monday,
with a subsequent increase in seas to 4-6 ft once again. Sunday and
Monday will present the next chance of SCA conditions. Coastal
troughing developing on Friday now appears more supportive of
scattered showers and thunderstorms, especially for the waters south
of Cape Hatteras. This risk then subsides over the weekend some,
before increasing again as we move into early next week.
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&&

.FIRE WEATHER...
As of 4 AM Thur...Minimum RHs will reach 35-40% this afternoon
(primarily away from the coast). Given the continued dry airmass,
dry fuels, and E`rly breezes, these conditions remain noteworthy
for any ongoing, or planned, fires.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
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NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ195-
     196-199-203>205.
MARINE...Small Craft Advisory until 8 PM EDT this evening for AMZ156-
     158.
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&&

$$
SYNOPSIS...MHX
NEAR TERM...MS
SHORT TERM...MS
LONG TERM...RM
AVIATION...RM/MS
MARINE...RM/MS
FIRE WEATHER...MHX