Greenwood, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

245
FXUS62 KGSP 300013
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
813 PM EDT Mon Jun 29 2026

.WHAT HAS CHANGED...
Updated the aviation discussion for the 00Z TAFs.

&&

.KEY MESSAGES...
1. Scattered showers and thunderstorms continue this evening,
mainly along/near I-26 in western North Carolina. Damaging wind
gusts and localized flash flooding both remain possible until
these storms diminish.
2. Heat risk will steadily increase through the week, with heat
indices likely exceeding 100 degrees across much of the Piedmont
and foothills, especially by mid to late week. Daily thunderstorms
will also be possible across the mountains.

&&

.DISCUSSION...
Key message 1: Scattered showers and thunderstorms continue this
evening, mainly along/near I-26 in western North Carolina. Damaging
wind gusts and localized flash flooding both remain possible until
these storms diminish.

A stout upper ridge continues to build in across the Deep South into
the Tennessee Valley. On the eastern flank of the ridge, deep-layer
northerly flow is in place over the Southern Appalachians. Low-level
convergence has fostered a plume of deep moisture and locally high 0-
3 km ThetaE air generally along and west of the I-26 corridor. With
2,500-3,500 J/kg of SBCAPE and 800-900 J/kg of DCAPE still in place
this evening (per the SPC mesoanalysis page), strong to severe
storms will remain possible through the early evening ours. The main
hazard with any severe storms that develop is damaging wind gusts. A
localized flash flood threat will also linger along the Blue Ridge
Escarpment through the early evening hours as activity continues to
develop, mainly over McDowell and Henderson counties. Drier and more
stable conditions will return later this evening into tonight.


Key message 2: Heat risk will steadily increase through the week, with
heat indices likely exceeding 100 degrees across much of the
Piedmont and foothills, especially by mid to late week. Daily
thunderstorms will also be possible across the mountains.

The synoptic pattern will continue to amplify through the week as a
deep trough digs down the west coast while a highly anomalous upper
ridge builds from the Tennessee Valley into the Southern
Appalachians. 500mb heights and 850mb temperatures will both be in
the 99th percentile for the end of June and early July and will
support a building heat wave as we head into the 4th of July holiday
weekend. Temperatures will climb into the mid to upper 90s by
Wednesday with upper 90s to low 100s common east of the mountains
Thursday through the weekend. Mountain valleys will likely see highs
in the low to mid 90s with mid to upper 80s even across the highest
elevations.

The biggest question is whether heat indices reach advisory criteria
of 105 degrees. Historically, for temperatures in the western
Carolinas and northeast Georgia to reach the low 100s we need
relatively dry soil along with dry air. Given ongoing drought
conditions and only scattered swaths of rainfall the last several
days these conditions would appear to be met. Diving deeper into
forecast soundings, and guidance indicates a very deep and well
mixed boundary layer with mixing as deep as 700 mb on the hottest
days this weekend. This in turn results in dewpoints mixing out into
the low 60s and perhaps even the upper 50s. This has major
implications on the heat index forecast with values struggling to
reach criteria despite air temperatures in the low 100s.
Furthermore, you can never rule out a ridge riding upstream
convective complex in these setups. Even if no rain makes it into
the area convective debris clouds could wreak havoc on daytime
temperatures. That being said, while confidence in reaching advisory
criteria is moderate at best, it will still be hot and heat related
stress leading up to and through the holiday weekend needs to be
taken seriously. Those with outdoor plans, including holiday and
recreation, should prepare for several days of elevated heat risk.
Stay hydrated, take frequent breaks in air-conditioned or shaded
areas, and never leave children or pets unattended in vehicles.

In addition to heat, daily afternoon thunderstorms will be possible
across the mountains where topographical influences should help to
initiate at least isolated to widely scattered storms each day. Most
of this activity should remain confined to the mountains, at least
through much of this week. As with any summer storms, a few could
become strong to severe. There are some indications that the pattern
could become more convectively active late weekend and beyond as the
upper ridge breaks down and northwest flow with embedded shortwaves
returns.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Dry and VFR expected east of the mountains
through the 00Z TAF period. KAVL will have the potential to see fog
and/or stratus develop again tonight so went with a TEMPO from 08Z-
12Z for MVFR fog, SCT IFR stratus, and an MVFR cig. Fog and stratus
should lift around daybreak Tuesday. Also went with a PROB30 for
TSRA and associated restrictions at KAVL as any TSRA chances will be
confined to the mountains Tuesday afternoon. Winds east of the
mountains will generally be ENE/NE through the period but could go
calm to light and VRB at times. Winds at KAVL will be mostly calm to
light and VRB through Tuesday morning before picking up out of the
SE Tuesday afternoon.

Outlook: Diurnal showers and thunderstorms are expected mainly
across the mountains through the workweek. Mountain valley fog/low
stratus will be possible each morning.

&&

.CLIMATE...
RECORDS FOR 07-02

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      93 1970     65 1943     70 2018     44 1988
                1954
                1931
   KCLT     101 1931     64 1943     76 1991     56 2008
                                        1970
                                        1931
   KGSP     101 1954     66 1943     77 1931     53 1899



RECORDS FOR 07-03

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      93 1970     65 1988     70 2018     50 2008
                1897                    1931        1937
                                                    1932
   KCLT      99 1931     70 1988     76 1925     56 2010
   KGSP      99 2016     70 1988     77 1925     56 1984
                1970
                1953



RECORDS FOR 07-04

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      97 1948     68 1976     70 2016     51 1986
   KCLT      99 1993     70 1968     76 1993     55 1933
                1955
   KGSP     100 1993     70 1988     75 2018     58 2021
                                                    1996
                                                    1933

&&

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

&&

$$

AR/TW