857
FXUS62 KGSP 182359
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
759 PM EDT Fri Jul 18 2025

.SYNOPSIS...
Daily mainly afternoon and evening shower and thunderstorm chances
continue through early next week. A few storms could produce
damaging wind gusts and localized flash flooding each day. A weak
cold front slowly crosses the area from the north Monday night into
Tuesday. This front will temporarily bring temperatures closer to
normal into mid week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 755 PM Friday...

Key Messages:

1) Heat Advisory Issued for Saturday from Noon to 8 PM for
Mecklenburg, Cabarrus, and Union (NC) Counties

2) Diurnal Shower and Thunderstorm Chances Return Saturday

3) Mountain Valley Fog and/or Low Stratus Possible Again Overnight
into Daybreak Saturday

A 597 dam anticyclone will drift westward over FL tonight, keeping
the jet stream to our north. A quasi-stationary front draped across
the Ohio Valley to the Mid-Atlantic Coast is expect to nudge
slightly further north of the forecast area through Saturday.

Scattered convection continues across western North Carolina and
northeast Georgia this evening. Activity has been gradually
weakening as it pushes eastward. With only about an hour of daytime
heating left before sunset, the window for severe storms is starting
to close...especially with the best DCAPE now located south and east
of current activity. The locally heavy rainfall threat will continue
as long as convection sticks around but should gradually taper off
after sunset. Mountain valley fog and low stratus may develop again
overnight. Lows tonight will end up 6-8 degrees above normal.

Saturday looks to be almost a carbon copy of today, with only
subtle changes in the air mass and overall flow. Given the mixing
occurring today, have blended in the NBM 10th percentile dewpoints
to lower them a few degrees during peak heating. This keeps heat
indices below 105 degrees for most locations. However, Heat Advisory
criteria (which starts at 105 degrees) looks to be met again
tomorrow afternoon for Mecklenburg, Cabarrus, and Union (NC)
counties. Thus, a Heat Advisory was issued for these locations from
noon to 8pm Saturday. Greenwood, Abbeville, and Elbert may come
close to heat index criteria so the Heat Advisory could be expanded
in later updates if forecast trends hold. Otherwise, similar trend
of timing and coverage of diurnal convection is expected on
Saturday. Also, similar environment for a few strong pulse storms
and isolated flash flood threat (again mainly NC mountains and I-40
corridor east).

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 1205 PM EDT Friday: Mid level ridging will slide slowly
westward through the short range period, but will act to keep hot
and humid conditions in place regardless. Highs both Sunday and
Monday will be 3-4 degrees above normal with high dewpoints leading
to heat indices near advisory criteria in our southern and eastern
areas.

Showers and thunderstorms will develop each afternoon and evening.
Pops will be pretty high in the mountains with lower pops in the
Piedmont. Overall, pretty typical conditions for late July.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 1210 PM EDT Friday: Mid level ridging briefly pushing west
will allow a weak cold front to impact the area Tuesday with
slightly less hot temperatures, i.e. near normal. The ridge will
rebuild through the rest of the week, so highs will climb back to
several degrees above normal after Tuesday.

Pops will be the highest with the front on Tuesday and then slowly
get lower through the week.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: VFR outside of afternoon and evening
SHRA/TSRA and overnight to early morning mountain valley fog/low
stratus. Scattered SHRA and TSRA continue across western NC while
isolated activity is noted across the SC Upstate as of 00z. Have a
PROB30 at KAVL and KHKY through 02Z as these terminals will have the
best chance to see TSRA. SHRA/TSRA should gradually wind down after
sunset with dry conditions expected to return late this evening into
early Saturday afternoon. Some patchy fog and/or low stratus may
develop at KAVL and KHKY overnight. Another round of SHRA/TSRA will
return Saturday afternoon and evening so have PROB30s at all
terminals. Winds will gradually decrease this evening, becoming
light tonight into early Saturday morning. Wind speeds will increase
again throughout Saturday with low-end gusts expected to develop
again mainly east of the mountains. Wind direction east of the
mountains will be mainly SW/WSW. Winds will mainly WNW at KAVL
through early Saturday before toggling more WSW Saturday afternoon.

Outlook: Daily thunderstorm chances will continue through early next
week each afternoon and evening. Low stratus and/or fog are possible
each morning, especially across the mountain valleys.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Heat Advisory from noon to 8 PM EDT Saturday for NCZ071-072-
     082.
SC...None.

&&

$$

SYNOPSIS...AR/DEO
NEAR TERM...AR/ARK
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...AR