817
FXUS62 KRAH 260626
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
226 AM EDT Sun May 26 2024

.SYNOPSIS...
High pressure ridging will build into the area Sunday. A cold front
will approach Sunday night and move through the region Monday night.
Dry high pressure will settle into the region toward the middle of
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 902 PM Saturday...

Isolated to scattered showers and storms continue to pop up across
portions of the central Piedmont, Sandhills and southern Coastal
Plain. At one point this evening, there were numerous outflow
boundaries across the Triangle, Sandhills, and Coastal Plain. Little
if any storms developed over the northwest Piedmont/Triad and
northern Coastal Plain. Satellite imagery reveals a weak mid-level
circulation over the southern Piedmont to Charlotte area. This
shortwave trough should continue to progress south and east
overnight. As this happens, convection should start to collapse
south and east into late tonight, dissipating overnight. The latest
HRRR suggests this may be the case, though the southern Piedmont has
not really been worked over in the sense of there still being some
SBCAPE present. As such, lingering/new outflows may spawn new
isolated/scattered storm cells across our southern areas for the
next 2-4 hours. Activity should largely be sub-severe, though a few
stronger cells could produce heavy rain and strong wind gusts.
Convection should wane after midnight as the shortwave moves east
and subsidence ensues. Lows should hover in the low to mid/upper
60s. Patchy fog could develop almost anywhere in central NC, though
may be more prone in areas of Raleigh and the eastern Sandhills,
where rainfall amounts were higher.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
As of 250 PM Saturday...

Sunday will start off dry across the area, some might see patchy fog
early morning but will clear shortly after sunrise. By the afternoon
an increase of showers and thunderstorms is expected. As the
enhanced shortwave trough progresses east from the IL/IN area during
the day, by the afternoon it is expected to be on the door step of
the Appalachian Mountains by late evening. Isolated to scattered
storms are expected to begin to evolve across the region late
afternoon. With loss of heating the severe threat is expected to
diminish through the overnight hours Sunday.  HiRes CAMs are showing
a bit more consistency with timing of the first round of storms
moving across the region late Sunday night through early Monday
morning. While this round of storms are expected to move across the
region swiftly, PW values are expected to be above normal (1.5-
2.0inches), thus some heavy rain could cause some minor flooding in
poor drainage areas. Drivers should be be extra cautious driving in
these storms at night. CAPE values will be lower than what is
expected with Mondays storms, but some storms could be strong. Kept
PoPs higher across the Northern Piedmont region, but chance PoPs are
generally across the region. Sunday will be warm, 5-7 degrees above
normal. Highs will be in the mid/upper 80s some areas reaching 90,
lows will range from upper 60s to low 70s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 145 AM Sunday...

Dry weather is expected during this period with generally low
humidity and seasonable to slightly below normal temps. The longwave
trough axis will still be to our W Tue, and while there may be minor
waves shifting through SC and SE NC, much of the deeper moisture
will have pushed E of our area or even offshore. Will keep a slight
chance of an afternoon shower or storm in our far SE, as large scale
models show the front slowing or lingering over our SE sections
where surface temps and dewpoints are apt to be elevated. A dry NW
flow will keep the column dry and stable Tue night through Wed,
although the notably cooler air will still be held up W of the
mountains until a secondary reinforcing dry cold front drops SE
through our area late Wed through Wed night. Behind this front,
dewpoints will drop even more, bottoming out in the 40s to low 50s
Thu/Fri as surface high pressure sourced from central Canada builds
in from the NW and N. By Sat, both temps and dewpoints will start to
rebound as the mid-upper longwave trough shifts out over the NW
Atlantic and amplified mid level ridging builds in from the west.
Low level thicknesses will rebound as the surface high starts to
shift off the Mid Atlantic coast, and thus temps will edge closer to
normal Sat. And with the onset of southeasterly low level flow and
an uptick in PWs, a few late-day showers may pop up across the S and
W, and will include just slight chances there. Temps will still be
near to slightly above normal Tue and near normal Wed, before
dropping to a few degrees below normal Thu/Fri with low humidity and
lots of sunshine. Near normal readings should return Sat. -GIH

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
As of 220 AM Sunday...

Cirrus clouds are rapidly exiting to the east with SKC overspreading
central NC. Patchy fog may still be possible near all TAF sites, but
with lowest confidence at GSO, INT, and RDU where crossover temps in
the low/mid 50s may be too low to see prevailing fog. FAY has
reported variable fog for a few hours and the 06z TAFs continued
this slow trend down to low-end IFR towards daybreak despite briefly
bouncing back to VFR around 0530z. Lingering shallow fog will
quickly dissipate through 12z with afternoon cumulus filling in
areawide with airmass showers/storms possible 17z-22z. Hi-Res
guidance tracks an MCS through the Mid MS Valley early this morning
and into the Carolinas through the evening hours. Latest forecast
attempts to capture the best time to see restrictions associated
with this system with prevailing VCTS based on latest CAM guidance
and with TEMPOs where confidence is highest (40-50% chances at GSO
and INT).

Looking beyond 06z Mon: A vigorous line of showers and thunderstorms
over the Ohio and Tennessee Valley early Mon morning will weaken as
it traverses the mountains and likely bring scattered to numerous
showers/storms through central NC during the day on Mon. Additional
showers/storms will be possible as the first of several cold fronts
moves through central NC Mon night. Dry and VFR conditions will
prevail through Thurs.

&&

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

&&

$$
SYNOPSIS...Kren
NEAR TERM...Kren
SHORT TERM...CA
LONG TERM...Hartfield
AVIATION...Swiggett