687
FXUS62 KMHX 220657
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
257 AM EDT Sat Jun 22 2024

.SYNOPSIS...
High pressure shifts offshore today, with troughing developing
in the lee of the Appalachians. A front approaches on Monday,
with another front affecting the region on Thursday.

&&

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

 - Increasing heat and humidity today

Early this morning, satellite imagery very nicely depicts a
weak area of low pressure moving ashore just north of
Jacksonville, FL. North of that low, a broad area of deep,
quality moisture has expanded inland from the Atlantic into
coastal areas of the Southeast U.S. Based on satellite imagery,
the northern extent of that moisture shield reaches into
southern sections of ENC. Daytime heating of this moist airmass
appears supportive of "airmass" showers, but a lack of
appreciable forcing should tend to keep the coverage isolated,
and should help keep the risk of deeper convection low. Guidance
suggests the area of deeper moisture won`t shift much today,
which suggests the greatest chance of showers will be along the
coast from Hatteras south through the Crystal Coast, and for our
southwestern coastal plain counties (Duplin and Onslow
Counties).

The bigger story today will be the start of an extended period
of hot and humid weather. While it is summer in ENC, this period
of heat and humidity comes on the heels of several days of less
humid, and not as hot, conditions. There`s still some residual
dry air just above the surface, so any mixing today may tend to
keep dewpoints in the upper 60s for most of the coastal plain.
While it will be hot, dewpoints in the 60s would tend to keep
heat indices around 100 degrees. If less mixing occurs,
dewpoints would hold in the 70s, and heat indices could top out
as high as 105 degrees. Because of the marginal nature of the
heat indices, the plan for now is to hold off on any heat
headlines.

&&

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

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

A modest increase in southerly winds aloft should help to pull
the plume of better quality moisture north through all of ENC
tonight. While forcing will be lacking, any area of moisture
convergence could support a few showers. In general, though, I
expect the main focus for showers to shift back offshore and
near the coast. Where skies clear out, light winds and a moist
boundary layer appear supportive of patchy fog (similar to the
past couple of nights). Widespread, impactful fog is not
expected, though.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 4 AM Friday...

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 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.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /through 06z Sunday/...
As of 130 AM Saturday...

 - IFR/MVFR VIS likely overnight (60-80% chance)

 - Daytime SHRA risk Saturday (10-30% chance)

In the very near-term (ie. through 12z Saturday), the main
forecast challenge will be the MIFG/BR/FG potential. Recent
satellite imagery shows some low clouds or fog attempting to
develop, but thus far, nothing appears widespread. Meanwhile,
surface obs have reported IFR, or lower, conditions at times.
Based on webcams and satellite, it appears the reduced VIS is
due to shallow fog (MIFG). Through the night, however, it`s
possible that some depth to the fog could be realized, and we`ll
be closely monitoring this in case a more impactful period of
FG develops. For now, I`ve leaned towards more of a MIFG type of
scenario. During the day Saturday, heating of a moist airmass
will probably allow isolated to widely scattered SHRA to develop
(similar to yesterday). The coverage is expected to be too
minimal for a mention in the TAFs. However, reduced VIS will be
a risk with any SHRA that develops. The TSRA risk isn`t zero
today, but Saturday`s setup isn`t all that favorable for TSRA.
By Saturday evening, the SHRA risk looks to shift back offshore.
Similar to the next few hours, Saturday night looks to support
another round of shallow fog.

LONG TERM /Sunday through Wednesday/...
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 kt gusts possible late Sunday.

&&

.MARINE...
SHORT TERM /through tonight/...
As of 200 AM Saturday...

 - Scattered showers and thunderstorms possible through tonight
   (20- 40% chance)

Satellite imagery this morning reveals 2 notable features. One
is a weak area of low pressure currently moving ashore just
north of Jacksonville, FL. The other feature is an upper level
low spinning about 80-100 miles off the ENC coastline. The FL/GA
low may lift slowly north along the coast today, but shouldn`t
have a big impact locally. The upper level low, meanwhile, has
had an area of showers and thunderstorms associated with it, and
this will impact portions of the coastal waters this morning,
and potentially longer. Otherwise, southerly winds will be on
the lighter side through tonight (5-15kt), and seas will hold
around 2-4 ft.

LONG TERM /Sunday through Wednesday/...
As of 4 AM Friday...SW winds increase on Sunday to 15-20 kt
with gusts to 25 kt. Seas will 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.

&&

.FIRE WEATHER...
As of 200 AM Saturday...

 - Elevated fire concerns possible Sunday

Recent RAWS observations suggest fine fuel moistures have
improved some, likely due to some shower activity the past 24
hours, and increasing ambient moisture off the Atlantic. This
combined with relatively light winds today should keep fire
concerns low. For any ongoing fires, the main concern today will
be a wind shift with the development, and passage, of the
seabreeze. Southerly winds increase on Sunday, becoming
sustained at 10-20 mph. RH will continue to increase, and is
forecast to only bottom out in the 40s and 50s. While not a
typical fire danger type of day, the breezy conditions and drier
fine fuels is noteworthy, especially for any fire that manages
to develop, or any ongoing fires. Wetting rainfall is still
possible on Monday and again Thursday.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement through this evening for NCZ195-196-
     199-203>205.
MARINE...None.

&&

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