Greer, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

206
FXUS62 KGSP 131329
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
929 AM EDT Fri Jun 13 2025

.SYNOPSIS...
Seasonably warm and humid weather, with numerous showers and storms
each afternoon and evening, can be expected through the weekend. A
warming trend will occur next week, and daily showers and storms
will continue through at least Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

1) Showers and thunderstorms this afternoon and evening, with heavy
rain and isolated flash flooding the main threat

2) Warm and humid east of the mountains

As of 922 AM EDT Friday: A few small showers are still lingering
over parts of the Upstate and NC Piedmont, but are quickly
dwindling. Overcast skies remain with a few breaks possible into the
late morning/early afternoon. A few changes to the PoPs for this
unsettled day.

A slow moving upper low will drift from the Ozark Plateau to the
Mid-MS River valley over the next 24 hours, while the Atlantic
subtropical ridge helps to keep a SW flow of moisture from the Gulf
that continues to lift northeastward across our region. Essentially,
this spells another day where/when a shower or thunderstorm
could develop at just about any time. However, that being said,
the CAMs generally keep coverage scattered at best well into the
afternoon. Some of this is related to the diurnal minimum and all
the lingering convective debris cloudiness that will help to keep
deep convection from really getting going until said clouds break
up. This should skew the above-climo precip probs into the likely
range later in the day, quite possibly with most of the shower/storm
activity being more in the evening. It would not be a surprise to
see that we should be holding onto the higher precip chances well
into the overnight just as we have seen currently. Generally poor
lapse rates and high precipitable water suggest that heavy rain and
isolated flash flooding are the main threats again with anything
that develops later today. The Marginal in the Excessive Rainfall
Outlook for today seems like a valid concern. Temps will probably
be held more in check because of extensive cloud cover. Tonight
will be another mild night as well.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 236 AM EDT Friday...

Key Messages:

1) Diurnal showers and thunderstorms will develop over the weekend,
with at least scattered activity both afternoons.

2) Near-normal temperatures are expected through the weekend.

Not much has changed regarding the weekend pattern.  We`ll start
out the period with a 594dm 500mb high over the Desert Southwest,
while a Bermuda high develops over the western Atlantic.  Sandwiched
between these two features, the Carolinas will be subject to a
stream of low-level moisture embedded in deep-layer SW flow...and
diurnally-driven instability both Saturday and Sunday afternoon.
Instability looks to be limited by some mid-level warming /
generally poor lapse rates...which will hinder stronger convective
rain rates from developing...and keep QPF response in check through
the weekend.  That said, what convection does develop will be
subject to 0-6km shear of up to 20kts...so although not all this
shear may be realized by shallow, anemic updrafts...at least
loosely-organized cells can`t be ruled out Saturday afternoon.
Near-normal temperatures are expected.

A modest increase in forcing is expected on Sunday as a broad,
deamplifying trough lifts out of the lower Mississippi Valley.
Forecast soundings still indicate enough mid-level warm air will be
in place to inhibit stronger updrafts, but the increased forcing
should improve overall coverage of convection Sunday relative
to Saturday, and alongside higher PWs, this generally increases
QPF response.  Temperatures Sunday will be similar to or just a
hair cooler than Saturday.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 251 AM EDT Friday...

Key Messages:

1) Rainy, unsettled weather continues, with diurnal showers and
thunder expected most of the week.

2) Temperatures will hit a warming trend, reaching the 90s by
Thursday.

The pattern won`t change much for the bulk of the long-range
forecast.  A subtropical ridging intensifies the first half
of the week, the Bermuda high will retrograde ever-so-slightly
westward, further increasing thicknesses and resulting in steadily
increasing temperatures through the period.  Meanwhile, moisture
will continue streaming into the area within SW low-level flow.
Indeed, for much of the period, NAEFS ensembles depict PWs in the
90th percentile or above...supportive of elevated QPF response
with diurnal thunderstorms.  Severe risk will continue to be
moderated by warm air at the mid-levels, and a lack of robust
synoptic forcing...in favor of low-end, isolated hydro issues
associated with convective rain rates and aforementioned PWs.

By Wednesday afternoon, low-level flow will turn increasingly out
of the W...not cutting off moisture flux but making it decidedly
less efficient.  Indeed, PWs are depicted leveling off and
trending back toward normal in long-range ensembles from Wednesday
onward...although the synoptic pattern will remain in place until
at least Thursday.  The latter half of the week will feature a
trough developing over the Dakotas, possibly cutting off from
the mean flow, and traversing the lower Midwest before arriving
in the Carolinas on Thursday.  Its attendant surface cold front
will at least approach from the west by Thursday evening...but
ensemble guidance is split on whether the front, and the drier
air it promises to usher in, will actually make it to GSP`s area
by Friday morning and the end of the seven-day forecast.  So,
the bigger story will simply be increasing temperatures...with
highs expected to hit the 90s by the end of the week.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Remaining light precip continues to weaken
over the western Piedmont at daybreak. In its wake, we have a
mixed bag of ceiling restrictions ranging from LIFR to VFR across
the region, which will have to be dealt with for another hour or
two. Once established, it may take until the middle part of the
morning to start breaking up the lowest cloud deck. The mid/late
morning look relatively quiet in terms of convection, but once
the low clouds break up, heating will quickly destabilize the
atmosphere and new storms will develop, just about anywhere at
any time. Will handle this with a PROB30 for now until we can fine
tune the timing of the best chances for thunderstorms. Friday night
looks very similar to tonight. Once we get rid of the precip again,
more restrictions are likely in the pre-dawn hours.

Outlook: Mainly diurnal showers and thunderstorms are expected each
afternoon/evening thru early next week. There will be potential
for late night and early morning fog and low stratus restrictions
each day.

&&

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

&&

$$

SYNOPSIS...MPR
NEAR TERM...CP/PM
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...PM