Area Forecast Discussion
Issued by NWS Greer, SC

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
030
FXUS62 KGSP 241756
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
156 PM EDT Fri Jul 24 2026

.WHAT HAS CHANGED...
Updated for 18z aviation package.

&&

.KEY MESSAGES...
1. Potential for at least localized excessive rainfall continues
through Saturday.
2. A return to typical mid-summer weather begins Sunday and
continues through Tuesday, with hot temperatures and at least
isolated diurnal convection expected. Another cold front may
reach the area in the middle of next week.

&&

.DISCUSSION...
Key message 1: Potential for at least localized excessive rainfall
continues through Saturday.

Quasi-stationary frontal boundary has set up in wedge-like fashion
just south of the CWA with very stable air in place. Weak upglide
from overrunning tropical moisture has set the stage for ongoing
showers and elevated thunderstorms across the southern half of the
CWA. Some of the more potent showers and thunderstorms will have
very efficient rainfall rates as PWAT values exceed 2" and a very
deep warm cloud layer is evident in vertical profiles. If multiple
rounds or training storms are occurring over the same area, this
could lead to a localized flash flood threat this afternoon and
evening, mainly across the southwest NC mountains and Upper Savannah
River Valley, closer to the vicinity of the frontal boundary. With
the base of the weak upper trough over the Eastern Seaboard, an
embedded shortwave is expected to move within the mean flow across
the area later this evening to go along with a few hundred J/kg
of MUCAPE, which should provide a slight enhancement of elevated
convection across the CWA. CAMs aren`t handling this well as far
as coverage, but there is a signal for the convection to linger
into portions of the overnight period. Confidence is too low to
warrant a Flood Watch for Flash Flooding as the threat will be too
localized. Highs today will struggle to even reach 80F across much
of the area with overcast to broken stratus and precipitation.

On Saturday, the upper trough will sharpen with more 500mb vort
energy in place as this axis moves across the region. The front
should sag further south, with drier air aloft filtering in. This
should promote weak low-level downsloping in the northern half
of the CWA, promoting clouds to scatter and allowing for more of
a typical diurnal trend in convection. Heavy rainfall rates will
accompany any showers and thunderstorms, which could promote a
very localized area for flash flooding, but the threat is lower
compared to yesterday and today as the activity will become more
progressive. Afternoon highs on Saturday are forecasted to run a
category or so below normal.


Key message 2: A return to typical mid-summer weather begins Sunday
and continues through Tuesday, with hot temperatures and at least
isolated diurnal convection expected. Another cold front may reach
the area in the middle of next week.

Trough axis will shift and depart the area by Sunday as drier
vertical columns are present with the frontal boundary continuing
to push further south, away from the CWA. In return, an amplifying
mid/upper-level anticyclone gradually propagates eastward from the
southern/central High Plains and Rockies, while upper-troughiness
remains over the northeastern CONUS. Warmer thicknesses and more
sunshine will become established and allow for temperatures to
trend warmer back near to slightly above normal from Sunday through
Tuesday. Expect typical diurnal convection to develop over the
mountains during this time frame, with less coverage slipping
off the terrain and moving across the foothills and Piedmont
areas. With the orientation of the anticyclone and trough over the
Northeast, expect northwesterly flow aloft to be favorable for
possible MCS track or two. Guidance is messy as far as exact
location and timing, but will need to monitor the progression of the
overall synoptic scale pattern and associated kinematics in order to
gauge the overall threat level for the CWA between Monday night and
Wednesday evening. The next cold front will move into the area from
the northwest Wednesday and Thursday, which will help lower
temperatures in response to better coverage in convection and
overall cloud cover.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: IFR stratus remains in place over the
terminals, with a few pockets of MVFR possible through the afternoon
before all sites return to IFR overnight. MVFR vsby lingers
through the afternoon through the overnight hours and into daybreak
Saturday, especially in locations that receives -DZ or SHRA. Decided
to go with prevailing VCSH with ongoing showers around and tried to
best time SHRA with PROB30s through the overnight period. Can`t rule
out TSRA, mainly near KAVL and KAND this afternoon. All sites will
experience prevailing IFR cigs through at least daybreak Saturday,
with some of the terminals possibly lowering to LIFR/VLIFR during
the pre-dawn hours. Guidance shows improvements by mid-morning
Saturday and beyond as low stratus will begin to lift and scatter
by then with better daytime heating. Another round of showers and
thunderstorms are possible Saturday afternoon/evening, but coverage
will be limited. Breezy northeast winds at all TAF sites expected
today, with the exception of KAVL where the direction will be from
the southeast. Winds should go mostly light and variable overnight.

Outlook: Drying is in order for Sunday and Monday, so convection
and restrictions look less likely. Low stratus and/or fog will be
possible each morning in mountain valleys and any locations which
receive heavy rainfall by day.

&&

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

&&

$$

CAC