-- Discussion containing changed information from previous version are highlighted. --
760
FXUS62 KMHX 201729
AFDMHX

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

.SYNOPSIS...
High pressure continues to extend across the Carolinas with weak
coastal troughing in place through Friday. 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.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 1010 AM Thu...High pressure remains firmly planted over
the mid-Atlantic and Carolinas this morning as a weak tropical
wave/low, currently northeast of the Bahamas, drifts towards the
far southeastern coastline. Low-level moisture continues to
increase but ridging and subsidence aloft will prevent anything
more than spotty sprinkles or weak showers to develop along sea
and sound breezes. Probability is too low for mentionable PoPs
this update. Warm conditions persist as highs climb to near 90
for the inner coastal plain, low to mid 80s along the water.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
As of 4 AM Thursday...We`ve been incredibly dry, but moisture has
slowly been increasing due to persistent easterly flow, and tonight
will present a better chance for patchy fog development. With
clearing skies and decoupling winds, the coastal plain has the best
shot at seeing some patchy fog. The overnight period will otherwise
be quiet with lows ranging from the low 60s across the coastal plain
to low 70s along the beaches and OBX.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
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.

Friday: Deterministic and ensemble guidance have trended back
towards something of interest attempting to develop in the SW
Atlantic, albeit weak, and the NHC has increased the probability of
development up to 30%. Guidance is pretty well clustered with the
low moving ashore along the GA/FL coast, and this makes sense given
the sprawling ridge to the north. Closer to home, what`s notable is
that a sharpening coastal trough is forecast to develop within a
moistening and destabilizing airmass along the coast. Short-term
guidance is in good agreement showing scattered showers and
thunderstorms developing along the trough, potentially impacting the
immediate coastal areas from Hatteras south through the Crystal
Coast. In light of this, I increased the chance of precip some
during this time, especially during the day Friday. As the above-
mentioned low moves inland, the coastal trough weakens, and the
chance of showers should follow suite.

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.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.MARINE...
SHORT TERM /through Thursday/...
As of 4 AM Thursday...Persistent easterly flow and swell from a
distant tropical wave have generated 6 ft seas across the outer
coastal waters south of Oregon Inlet. These conditions are expected
to linger a bit longer, so the existing SCA was extended until 8 PM
Thursday for the waters between Oregon Inlet and Ocracoke Inlet and
until 4 AM Friday for the waters south of Ocracoke Inlet. 10-15 kt
easterly winds with gusts close to 20 kt will continue through the
period. Chances for shower and thunderstorm activity for the central
and southern waters will be on the rise starting tomorrow evening
due to a local coastal trough.

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.

&&

.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...
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 AMZ152-
     154.
     Small Craft Advisory until 4 AM EDT Friday for AMZ156-158.

&&

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