094
FXUS62 KGSP 070506
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
106 AM EDT Tue May 7 2024

.SYNOPSIS...
A summerlike weather pattern lingers through mid-week with mainly
diurnal showers and thunderstorms expected. Temperatures will trend
well above normal through Thursday. Showers and thunderstorms will
become more numerous ahead of a strong cold front on Thursday.
Activity may linger through early Friday as the cold front pushes
east of the western Carolinas. Drier conditions and below normal
temperatures return for the weekend as high pressure builds in from
the west.

&&

.NEAR TERM /THROUGH TODAY/...
As of 100 AM EDT Tuesday: A second line of convection is now pushing
across the NC/TN border as of the writing of this AFD. Another line
of convection continues tracking eastward across the NC Piedmont and
eastern SC Upstate this morning. Storms have weakened compared to
the previous update, but a few strong storms will remain possible
with this activity. The main hazards with stronger storms are small
hail and gusty winds. Locally heavy rainfall may develop and lead to
minor flooding issues overnight, especially for areas that
repeatedly see storms track overhead. Once again increased PoPs
based on the latest KGSP radar loops so have high high-end chance to
low-end likely PoPs the next few hours.

Otherwise...as flow turns NW aloft, CAM guidance continues to depict
additional waves of scatter showers and thunderstorms through the
overnight hours...which should eventually fizzle as instability
wanes. Instability will be minimal but nonzero, and shear will
remain elevated...such that a few stray strong storms couldn`t be
ruled out. Low temps early tomorrow will be roughly 10 degrees above
climatology again.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
As of 215 PM EDT Monday: A flat upper ridge will be in place across
the area Wednesday with weak short waves rippling through the flow
and across the area. A stronger short wave crosses the area early
Thursday as an upper low moves into the Great Lakes. At the surface,
a weak east/west oriented front stalls over the area Wednesday, with
a cold front moving in from the west on Thursday. The air mass
becomes very unstable Wednesday with moderate shear and mid level
dry air leading to increased DCAPE and sfc delta Theta-E values.
Coverage will be higher across the mountains, but severe storms will
be possible at any location across the area given these parameters.
Moisture increases on Thursday with less mid level dry air, DCAPE,
and sfc delta Theta-E values. Instability also falls, but could
remain in the moderate range while shear increases, approaching
strong territory. Convective coverage still favors the mountains,
but at least likely PoP will be featured across the area. Severe
storms will again be possible, but overall chance is more uncertain.
Highs Wednesday will push 90 degrees outside of the mountains, and
mid to upper 80s in the valleys then fall a few degrees Thursday.
Lows will be well above normal as well.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 240 PM EDT Monday: The Great Lakes low opens into a trough
which moves into the area Friday. A series of short waves keeps the
general troughiness over the eastern CONUS through the end of the
period. With the trough moving in on Friday, cyclogenesis takes
place near the Carolina coast along the cold front that moves
through on Thursday. Guidance keeps going back and forth on the
location of the front and cyclogenesis, along with any lingering
moisture and resulting precip. Have continued the trend of chance
PoP for now given the uncertainty. A series of weak clipper-like low
pressure centers of frontal systems move near or over the area
through the rest of the period. This leads to isolated to possibly
low end scattered showers for the mountains each day with dry
conditions elsewhere. Temps fall to a few degrees below normal by
Saturday, then rise back to near normal through the end of the
period.

&&

.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Convection is underway across the SC
Upstate and parts of the NC mountains.  Most model guidance
doesn`t bring this activity to KCLT directly, although some
lingering showers could certainly make it in the next 1-2 hours.
Some guidance depicts a round of showers and embedded thunderstorms
arriving from the west around and after midnight, but should this
develop it would mainly affect KAVL and the Upstate terminals.
IFR VIS and CIG restrictions are expected again tonight, with
the worst VIS expected for the mountain sites and the worst CIGs
expected virtually everywhere.  This should scatter out quickly
after daybreak Tuesday, followed by prevailing VFR through the
end of the period.  Some additional convection is possible in the
afternoon, but mostly looks to stay confined to the NC zones...and
may not even escape the mountains.

Outlook: Moist profiles will combine with a weak/stalled front
thru the mid-week, resulting in a period of active, mainly diurnal
convec- tive weather each day. There is potential for restrictions
associated with widespread fog and/or low clouds each morning. A
cold front moves in later in the week with continued chances of
diurnal convection.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$

SYNOPSIS...AR
NEAR TERM...AR/JPT/MPR
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...MPR