-- Discussion containing changed information from previous version are highlighted. --
171
FXUS62 KRAH 161837
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
237 PM EDT Sun Jun 16 2024

.SYNOPSIS...
Deep high pressure will build over the Mid Atlantic and Carolinas
through mid week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 155 PM Sunday...

Afternoon satellite imagery reveals that continued moist
upslope/upglide has persisted across the west and northwest
Piedmont. Dewpoints in this region are in the upper 60s, while they
have mixed out into the upper 50s to low 60s over the Coastal Plain.
With the high to our north and east, southeast flow has kept clouds
socked in over the Triad region, with temperatures hovering in the
upper 70s to near 80. Spotty showers continue to develop in this
flow, likely driven by some weak instability above the surface
inversion. As the afternoon continues to wear on, we should see some
breaks in the clouds to allow highs to rise some 3-4 degrees from
current readings. Elsewhere, highs are on track with most areas in
the mid/upper 80s, to low 90s in the Sandhills.

Mesoanalysis shows that the majority of the surface-based and mixed-
layer instability is confined across the NC mountains and near KCLT.
Satellite imagery also reveals little vertical growth of cumulus in
central NC at the moment. As such, there remains that low-end chance
of a shower or storm in the west into the early evening, but most
areas are likely to be dry.

The moist upglide will continue overnight tonight across the west,
with a better signal of low stratus in the northwest Piedmont. Three
out of the 5 high-res models also show weak shower activity
developing toward sunrise Mon over the Triad once again, tied to
instability above the surface-based inversion. We have introduced
low-end rain chances as a result. Overnight lows are expected to be
in the middle 60s across the east to upper 60s to low 70s over the
west.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 215 PM Sunday...

Monday be a near carbon copy of today.

The strong 593 dm upper level anticyclone centered over NC is
forecast to strengthen ever so slightly(594-595 dm). Surface ridge
axis and associated feed of drier, less humid air will remain along
eastern/coastal portions of the Carolinas. Weak lift, moisture
return and destablization on the western periphery of the low-level
ridge axis will continue to support mainly diurnal isolated to
widely scattered showers or thunderstorm over the higher terrain.
Like today, a few of these showers and weaker cells could develop or
move into the far western Piedmont, where gradual lifting of morning
stratus layer will occur. Elsewhere, dry conditions will persist.

Given no appreciable change in airmass, expect comparable temps to
today; highs ranging from mid 80s north/northwest piedmont to lower
90s south.

While the model signal is not as strong as tonight/Monday morning,
low-level E-SELY feed into the area will continue to promote the
development/advection of areas of stratus across central NC,
especially across western and southern NC.  Lows in the mid/upper
60s, with some lower 60s possible over the northern portions of the
coastal plain and piedmont.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
As of 230 PM Sunday...

The extended forecast period begins with an unseasonably strong mid-
level anticyclone centered over the Mid-Atlantic and deep layer
moisture around 1 inch (50-60% of normal) which will keep conditions
dry and temperatures slightly above normal. Tues night through Wed
the mid-level anticyclone will lift north and strengthen into a
seasonably historic H5 ridge nearly 600dam ridge over the Northeast
and Mid-Atlantic. The position of the H850 anti-cyclone will keep
mostly easterly winds off the Atlantic and prevent 20 degrees C
isotherm and the dangerous heat wave pinned west of the Appalachian
mountains into the Northeast with slightly above normal highs for
central NC.

This will begin to change as the anticyclone weakens and shifts ESE
over the western Atlantic and Bermuda region into the weekend. This
will promote southwesterly H850 flow and advection of upper teens to
low 20s degree C temps into the Southeast and southern/central Mid-
Atlantic, favoring increasing temperatures heading into the weekend.
Confidence in finer details remain low in regard to how cloud cover
and/or precipitation chances from an inland surge of moisture off
the Atlantic late week into the weekend will affect afternoon high
temperatures. However, the pattern would support unseasonably
warm/humid conditions during the afternoon and less ability to
recover overnight and lead to a moderate chance for heat related
illnesses primarily for heat-sensitive groups and especially anyone
without effective cooling or hydration readily available this
weekend.

NHC continues to highlight a low chance for an area of low pressure
to form by midweek near the central Bahamas. Guidance remains split
with most surface features confined to GEFS while the EPS/GEPS
showing an inverted trough shifting inland over the Southeast late
Thurs into Fri. Regardless of development, increasing deep-layer
moisture will bring a chance for diurnal showers/storms to the area
with best chances across the southern Piedmont, Sandhills, and
southern Coastal Plain into the weekend.
-- End Changed Discussion --

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 110 PM Sunday...

VFR conditions are expected to start the TAF period. Moist
upslope/upglide has persisted across the Triad terminals today.
Instability trapped below the inversion has led to spotty showers.
These showers are possible to start the TAF period. Afternoon
convection looks to stay confined west of GSO/INT later this
afternoon/evening. The moist southerly flow around the high to our
northeast will favor a better chance of MVFR to perhaps IFR stratus
over GSO/INT Mon morning. Confidence is highest at INT and lesser at
GSO. These sub-VFR CIGs should lift to VFR by the end of the TAF
period. Some showers may also develop at GSO/INT Mon morning to
early afternoon with continued weak instability above the subsidence
inversion.

Outlook: An isolated shower/storm is possible at GSO/INT Mon
aftn/eve. Otherwise, VFR conditions are expected the remainder of
the period.

&&


.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Kren
SHORT TERM...CBL
LONG TERM...Swiggett
AVIATION...Kren