Area Forecast Discussion
Issued by NWS Greer, SC

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280
FXUS62 KGSP 291754
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
154 PM EDT Wed Jul 29 2026

.WHAT HAS CHANGED...
No significant changes to the previous forecast. The Aviation
discussion was updated.

&&

.KEY MESSAGES...
1. Near-normal temperatures with relatively low humidity through
Friday, and a near-zero chance of rain.
2. Another frontal system is expected to arrive from the west
this weekend, possibly stalling across our area early next week,
bringing back high rain chances but also below-normal temperatures.

&&

.DISCUSSION...
Key message 1: Near-normal temperatures with relatively low humidity
through Friday, and a near-zero chance of rain.

The cold front appears to have moved south of the forecast area, but
the dry and cooler air has been slow to move in from the N/NW thus
far. As a result, the southern parts of the forecast area around
the Lakelands may still end up with a hot day with highs in the
mid-90s and lingering humidity, while the parts north of I-40 should
start to feel the air mass change this afternoon. Deep convection
is not expected, but a stray shower will not be completely ruled
out close to the TN border where the NW flow upslope could help
to overcome any inhibition.

We should feel the air mass change overnight and into Thursday as
the sfc high drops in from the Midwest, supported by the upper
ridge axis stretching from the southwestern Plains to the Great
Lakes. Temps will be on the order of a category on the cool side
of normal, but more importantly, the dewpoints will drop back
to the upper 50s and lower 60s which should drop the afternoon
RH into the 35-40 percent range. Aaahhh. Should be a right nice
day. Alas...the air mass will modify into Friday...and temps will
creep back to normal or maybe a few degrees warmer. There will be
almost no chance of precip through Friday night, unless a stray
ridgetop shower develops during peak heating.


Key message 2: Another frontal system is expected to arrive from
the west this weekend, possibly stalling across our area early
next week, bringing back high rain chances but also below-normal
temperatures.

By late Friday, a short wave topping the upper ridge to our west
will be moving across the northern Plains. That wave should dive
southeast to the Midwest Friday night as an upper ridge axis moves
over our area. By Saturday morning, with the ridge axis to our
east and sfc high pressure off the Carolina coast, the return of
moisture and humidity from the south will begin in earnest. This
might not be in the form of a returning warm front, but the effect
will be the same. Meanwhile, the short wave will approach from
the west. The model guidance shows the development of mid/upper
forcing associated with that wave, which arrives over the region
by peak heating on Saturday if the timing doesn`t slip. So, after a
few quiet days, it looks like a quick ramp-up to above climo precip
probs. Nothing out of the ordinary thunderstorm-wise for mid-summer,
just more of it. There is a growing consensus among the models for
this wave cutting off a low over the TN valley region by Monday
then lingering into the middle part of the week, in which case
we would have another period of numerous showers and storms and
perhaps an increasing risk of heavy rain as precipitable water
climbs well above normal. The increase in cloudiness and precip
coverage would act to keep daytime highs at or below normal.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere: With the sfc front well to our south, all
terminals are expected to remain VFR through the period as high
pressure builds in from the N to NW. Some high-based cu will affect
mainly the NC terminals through peak heating. Those clouds should
melt away with sunset. Wind should stay N to NW, with occasional
gusts at some locations, though maybe not as much as previously
thought. The dry air mass will arrive overnight, which means the
chances for mtn valley fog are very low. On Thursday, wind will
return light from the N or NNE, and a few fair weather cu may
form again.

Outlook: Dry and VFR through Friday, with shower and thunderstorm
chances and associated restrictions returning this weekend into
early next week. Low stratus and/or fog will be possible each
morning starting Friday, mainly in the mtn valleys.

&&

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

&&

$$

PM