900
FXUS62 KGSP 161015
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
615 AM EDT Sun Aug 16 2026

.WHAT HAS CHANGED...
No significant changes to the forecast early this morning.

The aviation forecast was updated for the impending 12Z TAF
issuance.

&&

.KEY MESSAGES...
1. A Heat Advisory is in effect once again for Upstate SC,
northeast Georgia, and the Charlotte Metro area for Sunday
afternoon. Hot and humid weather continues for most of the week,
with triple digit heat index likely over the low terrain each
afternoon.
2. Diurnal convection develops each afternoon this week, with a
couple of strong to severe storms as well as isolated nuisance
flooding possible each day.

&&

.DISCUSSION...
Key message 1: A Heat Advisory is in effect once again for Upstate
SC, northeast Georgia, and the Charlotte Metro area for Sunday
afternoon.  Hot and humid weather continues for most of the week,
with triple digit heat index likely over the low terrain each
afternoon.

Stout subtropical ridging remains in place this morning, with the
core of a a 599dm h50 anticyclone centered over eastern Texas per
the latest RAP UA analysis.  This pattern still looks to remain more
or less unchanged through the remainder of the weekend and much of
next week.  The result will be widespread triple-digit heat indices
outside the mountains.  A heat advisory is in effect from noon
through 8 PM Sunday, for most of the SC Upstate, northeast Georgia,
and the Charlotte Metro area, where heat index values will creep
above 105 degrees during the hottest part of the day.  More heat
advisories will likely be needed the first half of the week.

Long-range ensembles continue to feature some cooling by the end
of the week, though they`ve backed off on timing until Friday or
even next Saturday.  Still think there won`t be a true air mass
change, so much as a weak burst of cooler air.  Still, any relief
from the heat will be appreciated.


Key message 2: Diurnal convection develops each afternoon this week,
with a couple of strong to severe storms as well as isolated
nuisance flooding possible each day.

With little change to the air mass - hot and humid, to be exact -
we can expect isolated to scattered diurnal thunderstorms each
afternoon from Sunday through at least Wednesday.  Lapse rates
will generally be poor, but rich instability will nonetheless
provide a good enough environment to support a couple strong to
severe storms each day.  Coverage will generally be best over the
mountains, where ridgetops will aid in convective initiation.

By Thursday or Friday, a weakness in the subtropical ridge
will provide the impetus for a weak cold front approach the area
(possibly pushing south across the region on Friday).  Depending on
timing, this could improve coverage over showers and storms Thursday
or Friday afternoon, and suppress convection in its wake.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Still expect generally clear skies, with
increasing cu coverage through early afternoon.  Another round
of isolated to widely scattered convection will develop in
the afternoon.  Confidence is limited on how much, if any, of
this convection will survive outside the mountains, but opted to
add PROB30s at GSP, GMU, and CLT this afternoon.  Mostly clear
conditions will return Sunday night, and another round of mountain
valley fog and low stratus is likely.

Outlook: Scattered showers and thunderstorms with associated flight
restrictions will be possible each afternoon thru at least the
first half of next week.  Low stratus and fog will be possible
each morning, especially in the mountain valleys.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from noon today to 8 PM EDT this evening for
     GAZ018-026-028-029.
NC...Heat Advisory from noon today to 8 PM EDT this evening for
     NCZ070>072-082.
SC...Heat Advisory from noon today to 8 PM EDT this evening for
     SCZ008>014-019-104>109.

&&

$$

MPR