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933
FXUS62 KMHX 210608
AFDMHX

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

.SYNOPSIS...
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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.
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&&

.NEAR TERM /TODAY/...
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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.
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&&

.SHORT TERM /TONIGHT/...
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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.
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&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
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As of 315 AM Thursday...

 - 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. Broad
surface troughing is 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 /06Z FRIDAY THROUGH TUESDAY/...
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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 315 AM Thursday...

 - Increased risk of TSRA and sub-VFR conditions Monday

Isolated SHRA and TSRA may develop 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.
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&&

.MARINE...
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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 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...
NC...Beach Hazards Statement from 8 AM EDT this morning through
     this evening for NCZ195-196-199-203>205.
MARINE...Small Craft Advisory until 5 AM EDT early this morning for
     AMZ156-158.

&&

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