118
FXUS62 KGSP 300653
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
253 AM EDT Sat May 30 2026

.WHAT HAS CHANGED...
No substantial changes.

&&

.KEY MESSAGES...
1. A potential for locally heavy rainfall and isolated flash
flooding continues today. Briefly cooler and drier on Sunday
before rain returns Monday.
2. Dry and cooler than normal weather is expected Tuesday through
at least Thursday. Slightly warmer with a small chance of diurnal
convection Friday.

&&

.DISCUSSION...
Key message 1: A potential for locally heavy rainfall and isolated
flash flooding continues today. Briefly cooler and drier on Sunday
before rain returns Monday.

The latest water vapor imagery depicts a short wave trough moving
across the Deep South, with a plume of deep moisture extending from
the central Gulf northeast through the Savannah River Valley into
the southern Appalachians. Weakening areas of showers with a few
isolated storms persist within this plume across the western part
of our forecast area. Individual cell movement has been relatively
progressive, and there hasn`t been much cell training observed, but
small convective clusters have shown some tendency to back build,
while there has also been some anchoring of convection observed
along terrain features along the TN/NC border. This has resulted
in very isolated areas of very heavy rainfall of 2+ inches. This
potential will continue across the high terrain through the morning,
and can`t rule out a stray flash flood event.

If anything, forecast profiles suggest a slight downtick in the
potential for locally heavy rain and flash flooding during the
daylight hours, as mean cloud-bearing winds accelerate slightly,
and the potential for back building of convective clusters
diminishes somewhat. Nevertheless, at least scattered showers
and some thunderstorms should persist into the afternoon in the
vicinity of weak frontal boundary, and increased instability should
keep the low-end flash flood threat going into the afternoon.

By this afternoon, stable air circulating around sprawling surface
high pressure building into the northeast quadrant of the country
in the wake of a cyclone departing the New England coast will
spill southwest down the eastern slopes of the Appalachians,
with inverted ridge building into our forecast area by this
evening. This will send the surface boundary southwest through the
CWA and bring an end to convection for much of the area by the
end of the evening. Cool/stable conditions persist into Sunday,
with temperatures around 10 degrees below normal forecast for much
of the area outside the mountains. Sunday PoPs are limited to the
western and southern periphery of the CWA, where some afternoon
instability is possible...especially across the mountains closer
to the TN border.

Moisture begins to increase yet again Sun night into
Monday...between surface high off the Southeast Coast, and ahead
of approaching cold front associated with an area of height falls
diving from the Great Lakes into the central Appalachians. PoPs
will once again ramp up Sunday night and especially Monday. Drying
with a little more staying power finally arrives (for the most
part) Monday evening. Other than the below-normal temps Sunday,
temperatures are forecast to be near-normal through Monday night.


Key message 2: Dry and cooler than normal weather is expected Tuesday
through at least Thursday. Slightly warmer with a small chance of
diurnal convection Friday.

Anomalously low height are forecast to persist near the East Coast
through much of the new work week, maintaining general low level/dry
ridging and cooler-than-normal temps through at least Thursday. A
short wave trough is forecast to dig down the western periphery of
the trough and into the forecast area Tuesday. The latest GFS is
especially strong with this feature and responds with a round of
convection Tue afternoon. This is generally at odds with the other
global models, but it nevertheless seems prudent to advertise a
small PoP. Dry weather with temps around 5 degrees below climo are
otherwise forecast through Thursday. Temperatures and moisture are
forecast to increase to near-normal by Friday, and small chances
for diurnal convection are warranted for the end of the week.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Showers and isolated TS persist across the
western third of the Terminal Forecast Area early this morning. In
the immediate near term, shower potential is expected to be
confined to the upstate SC terminals and perhaps KAVL, but even
at these sites, impact from SHRA is expected to be little. Can`t
completely rule out a stray TS at the western sites early this
morning, but this is highly unlikely and not worthy of a TAF
mention. Guidance sources are mixed (to say the least) regarding
the potential for low stratus development later this morning...with
the general consensus being that low clouds will largely remain
just west of the area. However, considering that areas near KAND
have seen a little more precip than earlier model projections...it
stands to reason that restrictions will develop a little farther
east...and a tempo for IFR cigs has been introduced at KAND between
08-10Z. Confidence is lower at the other TAF sites, but there`s
enough of a potential to advertise at least tempo conditions for
SCT IFR layers at KGSP/KGMU later this morning.

Scattered showers and some thunderstorms are expected to expand
along a boundary bisecting the area from WNW->ESE late this
morning into the afternoon...with Prob30s for TSRA warranted at
all locations except KHKY...which is expected to remain on the
cool/stable side of the boundary. Still...a Prob30s for -SHRA is
warranted there. Coverage of convection is forecast to wane quickly
this evening, as more stable air begins pushing in from on NE winds
increasing to 5-10 kts. In the interim, winds are mainly expected
to be SW at 5-10 kts.

Outlook: Drier conditions return Sunday before another cold front
brings convective chances back Monday. A drier pattern should return
for the rest of the workweek.

&&

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

&&

$$

JDL