Spartanburg, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

638
FXUS62 KGSP 282333
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
733 PM EDT Sun Jun 28 2026

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

&&

.KEY MESSAGES...
1. Shower and thunderstorm chances return tonight, mainly west of
I-26. Fog and low stratus may develop overnight, especially in
the mountain valleys and in any areas that received appreciable
rainfall today.
2. Heat risk will steadily increase through next week, with heat
indices potentially exceeding 100 degrees across much of the
Piedmont and foothills, especially by mid to late week.

&&

.DISCUSSION...
Key message 1: Shower and thunderstorm chances return tonight, mainly
west of I-26. Fog and low stratus may develop overnight, especially
in the mountain valleys and in any areas that received appreciable
rainfall today.

Dry conditions have returned across the forecast area this evening.
A few showers and perhaps thunderstorms will be possible, mainly
west of I-26 overnight. There will be no severe threat with any
thunderstorms that manage to develop. Skies will clear overnight,
but with low level moisture lingering, fog formation is possible,
although the extent of this may be limited due to developing
downslope flow. Fog will therefore be most likely across the
Piedmont...especially in locations that see appreciable rainfall
this afternoon...and in the usual fog-prone valleys beneath the
mountains along the TN/NC border. Min temps will be 2-4 degrees
above climo.


Key message 2: Heat risk will steadily increase through next week,
with heat indices potentially exceeding 100 degrees across much
of the Piedmont and foothills, especially by mid to late week.

An anticyclone and associated upper ridge will steadily intensify
over the Miss and TN Valleys early this week while gradually
shifting toward the central Appalachians during mid-week. This
will result in building heat through the week, with temperatures
expected to begin the week around 5 degrees above normal, ending
the week around 10 degrees above climo...when ambient temperatures
are forecast to reach the century mark across at least a portion
of the Piedmont. Heat Index values of 100+ are forecast to impact
the southern fringe of the CWA Monday and Tuesday...creeping N
and W to encompass much of the Piedmont and foothills from Thu
through next weekend. It should be said that confidence in the Heat
Index forecast beyond Tue or so is very low due to the high
sensitivity of dewpoint to the H.I. calculation...and the dewpoint
forecast is very uncertain, as they often tend to mix out more than
anticipated under the influence of strong anticyclones. While Heat
Index for the next couple of days is forecast to be at least several
degrees below climo Mon/Tue, values of around 105 are expected to
creep into Elbert Co, GA tomorrow afternoon. In collaboration with
NWS FFC, Elbert Co will be included in a Heat Advisory. Heat
Advisories are likely to continue through the week...gradually
expanding in coverage.

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.

Otherwise, with anticyclonic flow increasing aloft, the atmosphere
will become more subsident and suppressed in nature. This will
tend to limit overall coverage of deep convection, with generally
isolated-to-widely scattered activity expected each day across the
mountains, and isolated-at-most coverage across the remainder of
the area.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Mostly dry and mostly VFR through the 00Z TAF
period outside of the potential for mountain valley fog and low
stratus as well as the potential for scattered SHRA/TSRA, mainly
west of I-26. KAVL will have the best chance to see MVFR fog and IFR
cigs develop overnight as this terminal saw the most rain today.
Went ahead and maintained a TEMPO at KCLT for potential fog/stratus
overnight but confidence is low as rain occurred around the terminal
but not directly over it. Removed any mention of fog/stratus across
the remainder of the terminals as very little rain, if any, occurred.
Any fog/stratus that develops should lift around daybreak Monday.
Although KAND and KAVL will have the best chance to see SHRA/TSRA
develop in the vicinity tonight into Monday, confidence is too low
on whether activity will track directly over the terminals. Thus,
maintained dry conditions across all terminals through the 00Z TAF
period. Winds at KAVL will be mostly N/NNW but could go light and
VRB to calm overnight. Winds east of the mountains will gradually
turn more NW/N overnight but could also go light and VRB to calm
overnight. Winds  east of the mountains will gradually turn NE
throughout Monday.

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...Heat Advisory from noon to 8 PM EDT Monday for GAZ029.
NC...None.
SC...None.

&&

$$

AR/JDL