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213
FXUS62 KMHX 210809
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
409 AM EDT Fri Jun 21 2024

.SYNOPSIS...
Coastal troughing develops today, then weakens as high pressure
briefly noses in tonight. High pressure shifts offshore over the
weekend, with inland troughing developing, and continuing into
the upcoming week. A front, or two, may make a run at Eastern NC
next week.

&&

.NEAR TERM /TODAY/...
As of 200 AM Friday...

 - Coastal shower and thunderstorm risk today

Early this morning, a tropical wave and an associated area of
low pressure was located about 340 miles SSW of Cape Lookout.
This wave is moving westward and is forecast to reach the FL/GA
coast later today or tonight. The NHC continues to maintain
modest probabilities of a brief tropical depression developing
before landfall. North of that low, coastal troughing is
forecast to sharpen through the day. Meanwhile, satellite
imagery reveals a broad area of deeper moisture approaching the
ENC coast from off the Atlantic. Guidance is in good agreement
depicting this area of deeper moisture reaching the coast
through the day, but struggling to penetrate much further inland
of the coast. This will setup an area of modest moisture
convergence that, in tandem with the coastal trough and daytime
heating, should be supportive of isolated to scattered showers
and thunderstorms. I expect this coverage to be focused across
coastal Onslow County, southern Craven County, Carteret County,
and the southern OBX.

By mid to late afternoon, the coastal trough is forecast to
weaken as the above-mentioned low reaches the FL/GA coast, and
this should lead to a decreasing coverage of showers. Inland
away from the coast, highs should reach the 90s thanks to
limited cloudcover and increasing low-level thicknesses within
the developing southerly flow.

&&

.SHORT TERM /TONIGHT/...
As of 200 AM Friday...

 - Patchy fog possible tonight (20-40% chance)

As the seabreeze works inland this evening, boundary layer
dewpoints are forecast to rise into the 70s across most, if not
all, of ENC. Meanwhile, a transient area of surface ridging
nosing in should support light winds. At face value, this
suggests at least some potential for patchy fog development
(mostly likely of the shallow variety). However, short-term
ensemble guidance gives a 20-40% chance of more impactful fog
developing, and this will be something we`ll continue to monitor
in later forecasts. An alternative scenario, as seen in most
forecast soundings, is a low stratus deck of clouds developing,
which would tend to limit the fog potential. Regardless, the
combination of increasing dewpoints and rising thicknesses will
lead to a noticeably more mild night, with lows in the 70s for
most.

There`s a loose signal in the guidance for some lingering
coastal showers, but forcing doesn`t look as notable as during
the day today, so we`ll keep the chance of precip lower along
the coast for now.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
As of 4 AM Friday...

Saturday-Sunday...Surface high pressure over the Atlantic continues
to travel east, which will put ENC under southwesterly flow and
start a warming and moistening trend. Along the east coast, coastal
troughing will develop and last through the weekend. The main
lacking ingredient for a much needed widespread rainfall event
is instability, so the majority of shower and thunderstorm
activity this weekend will likely develop along the seabreeze.
Of more concern is the oppressive heat, especially on Sunday,
when "feels like" temperatures are expected to reach 100-105F.

Monday-Friday...We`ll remain mostly under southerly flow, which will
pump in ample moisture from the Gulf of Mexico and increase humidity
to uncomfortable levels. Diurnal PoPs are in the forecast each day
but better chances will be on Monday and Thursday due to a series of
frontal passages. The main points of focus for the coming week will
be triple digit "feels like" temperatures and the potential for
strong to marginally severe storms on Monday.

 - Dangerous Heat: With increasing heat and humidity, heat
   indices will reach the upper 90s to low 100s each day this
   week. This raises concern for heat related illnesses for
   those spending time outdoors. No heat headlines are in place
   as of now, but trends will be monitored.

 - Monday Storms: Instability and deep layer shear look to be
   plentiful across the area. If this holds, some strong to
   severe storms are possible.
-- End Changed Discussion --

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
SHORT TERM /through 06z Saturday/...
As of 115 AM Friday...

 - Periods of MVFR conditions possible through Friday night
   (50-70% chance)

 - TSRA possible along the immediate coastline Friday (20-30%
   chance)

An area of low pressure will track westward across the SW
Atlantic, reaching the FL/GA coastline later Friday or Friday
evening. North of the low, a zone of deeper low-mid level
moisture will attempt to work north and west towards the coast
of the Carolinas with an increased risk of sub-VFR CIGS. At this
time, it appears the greatest risk will be confined to the
immediate coastal areas, and I`ve opted to keep CIGs out of the
TAFs for now. Later Friday evening into Friday night, guidance
is showing a stronger signal for sub-VFR CIGs as moisture
continues to get pulled into the area. There`s still some
uncertainty regarding how quickly this moisture return will
occur, and I kept the TAFs VFR for now. Of note, as moisture
increases, there appears to be a decent opportunity for SHRA and
TSRA activity offshore and along the immediate coastal areas.
Like with the CIGs, it appears the greatest chance will be south
and east of our TAF sites, so no mention of SHRA or TSRA for
now. Lastly, both tonight and Friday night, there will be a
chance of sub-VFR VIS due to shallow fog. I stuck close to the
previous TAFs and kept a 5SM BR mention in to account for the
potential overnight. For Friday night, it`s less certain whether
it will be low stratus or FG, but either way there is a sub-VFR
risk worth monitoring.

LONG TERM /Tonight through Tuesday/...
As of 4 AM Friday...SHRA and TSRA development are possible each
day along the seabreeze. Monday will present the best
opportunity for sub-VFR conditions given an environment that
could support strong to marginally severe storms. Winds will
generally be SW with 20-25 kt gusts possible late Sunday.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
SHORT TERM /through tonight/...
As of 200 AM Friday...

 - Elevated seas continue south of Cape Hatteras this morning

 - Increased shower and thunderstorm risk today south of Cape
   Hatteras

A tropical wave, and an associated area of low pressure, were
located about 340 miles SSW of Cape Lookout early this morning.
It`s unclear how much swell is actually emanating from this low,
but persistent easterly flow is certainly contributing to
continued elevated seas of 4-6 ft early this morning. Given a
slower trend in waves laying down, I opted to extend the ongoing
SCA out several more hours. Additional extensions may be
needed. Eventually, the low moving ashore near the GA/FL coast,
and decreased winds should lead to sub 6 ft seas. For the most
part, winds will be easterly at 5- 15kt this morning, then
shifting to a southerly direction by tonight.

LONG TERM /Saturday through Tuesday/...
As of 4 AM Friday...Sub-SCA conditions will persist until
Sunday when SW winds increase to 15-20 kt with gusts to 25 kt.
Seas will be 2-3 ft on Saturday and build to 3-5 by later
Sunday. The new week will continue similar conditions with
gusts possibly dipping just below SCA criteria. Conditions
improve Tuesday after a cold front passes through, which will
generate variable winds at 10 kt or less and 3-4 ft seas
diminishing to 2-3 ft. Afternoon showers and thunderstorms are
possible each day but Monday presents the best chance for some
to be stronger to marginally severe.
-- End Changed Discussion --

&&

.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...
-- Changed Discussion --
NC...Beach Hazards Statement from 8 AM EDT this morning through
     this evening for NCZ195-196-199-203>205.
MARINE...Small Craft Advisory until 11 AM EDT this morning for AMZ156-
     158.
-- End Changed Discussion --

&&

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