GSP Forecast Discussion
214
FXUS62 KGSP 100557
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
157 AM EDT Thu Sep 10 2026
.WHAT HAS CHANGED...
No major changes.
&&
.KEY MESSAGES...
1. Dry and more humid today. Daily shower and thunderstorm chances
return Friday into early next week, peaking on Saturday. Although
the heat and humidity will peak on Friday, the humidity and above
normal temperatures will linger through early next week.
&&
.DISCUSSION...
Key message 1: Dry and more humid today. Daily shower and thunderstorm
chances return Friday into early next week, peaking on Saturday.
Although the heat and humidity will peak on Friday, the humidity and
above normal temperatures will linger through early next week.
The flattening upper anticylcone that has been over the Southern
United States the last few days gets pinched off into two separate
areas of high pressure today. One drifts westward and set ups over
the Desert Southwest while the other drifts eastward and sets up
just off the Southeast coast. The western periphery of the upper
high will remain extended over the Southeast through Friday,
allowing the heat and humidity to tick up each day. Although the
heat and humidity will peak on Friday, both humidity and above
normal temperatures will stick around through early next week as yet
another upper anticylcone builds back over the southern United
States. Although we are still not expecting to reach Heat Advisory
criteria (which starts at 105 degrees) any day through the forecast
period, locations in the Upper Savannah River should see heat index
values climb into the triple digits each afternoon through Monday.
Some locations in the Charlotte Metro should also see heat index
values climb into the triple digits, mainly on Friday. Confidence on
reaching triple digit heat index values on Saturday is low at this
time as more widespread shower and thunderstorm chances should limit
heat indices.
It still appears that a cold front will approach from the north
through Friday but confidence on whether the front actually makes it
into GSP forecast area remains low as it should reactivate as a warm
front and lift back north Friday night into early Saturday. Thus,
mostly dry conditions are expected again today with shower and
thunderstorm chances returning tomorrow, peaking on Saturday. 00Z
CAMs are not terribly excited about coverage tomorrow, showing
isolated to scattered (at best) activity, which lines up well with
the NBM which only has chance PoPs for Friday afternoon. Much better
coverage is expected on Saturday per the 00Z global model guidance
which matches up well with the NBM which has 70-90% PoPs by Saturday
afternoon. Should see activity become more suppressed, especially
east of the mountains, Sunday into early next week as the
aforementioned anticylcone builds back over the region. Could not
entirely rule out a low-end hydro threat, mainly on Saturday, with
above 90th percentile PWATs in place per the GFS and EURO. However,
confidence is low at this time as NBM rainfall totals continue to
look fairly muted through the weekend, ranging mostly from 0.30"-
0.60" east of the mountains and 0.50" to 1.5" in the mountains. It
still appears that this will be mostly beneficial rainfall. However,
we will closely monitor trends regarding rainfall amounts in the
coming days. Once the CAMs are able to go out through the entire
weekend we should have a better picture of whether the hydro threat
will be of much concern. The severe weather threat will remain very
low due to global models only showing 15-20 kts or less of deep
layer shear in place through early next week.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Dry and VFR again through the 06Z TAF period
outside of the potential for another round of fog and low stratus
across the mountain valleys and at KHKY. Thus, maintained the TEMPO
at KAVL for LIFR vsbys and cigs (09Z-13Z) and introduced a TEMPO for
IFR vsbys at KHKY (11Z-13Z). Confidence is higher that restrictions
will reach KAVL compared to KHKY. Fog and stratus will lift shortly
after daybreak. Winds will be mainly S/SW through much of the TAF
period. KAND and KAVL should see calm winds through daybreak. Calm
winds should return overnight at KAVL. Cirrus will continue
streaming over the terminals through the period, with cumulus
developing during the afternoon/early evening hours.
Outlook: A cold front just to our north will bring back daily shower
and thunderstorm chances (and possibly restrictions) Friday into the
weekend. The probability of morning fog/low stratus will also
increase, especially in the mountain valleys.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
AR
NWS GSP Office Area Forecast Discussion
