Simpsonville, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

241
FXUS62 KGSP 160608
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
208 AM EDT Sat May 16 2026

.WHAT HAS CHANGED...
No significant changes were made to the next seven days.

The aviation discussion was updated to reflect the 06Z TAF issuance.

&&

.KEY MESSAGES...
1. A summer-like pattern will gradually evolve through early
next week, with above normal temperatures and steadily increasing
humidity.
2. A cold front moving in from the northwest is expected to bring
better rain chances from Wednesday afternoon through Friday, but
probably not enough rain to make a dent in the drought. Cooler
temperatures return behind the front for the end of the week.

&&

.DISCUSSION...
Key message 1: A summer-like pattern will gradually evolve through
early next week, with above normal temperatures and steadily
increasing humidity.

A relatively flat upper pattern to start the weekend will gradually
amplify through Sunday and into Monday as a deep mid/upper trof and
low dig down across the Intermountain West and a ridge/anticyclone
builds along the East Coast in response. Hope you all enjoyed one
last cool night. This pattern will support a summer-like Bermuda
High that will allow for a warmup with temperatures climbing around
ten degrees above normal by Sunday and Monday, which translates into
highs in the upper 80s and lower 90s outside the mtns. Seasonally
hot, yes, but probably not high enough to challenge any record
highs. A corresponding increase in dewpoint will not be especially
noticeable for the next few days and the RH should stay low enough
that apparent temps will be essentially the same as air temps.

Whether or not the increase in moisture will be enough to fuel
any diurnal convection is an interesting question in light of
fcst soundings that reveal the presence of a remnant elevated
mixed layer...seen as mid-level lapse rates of 7.5-8 C/km during
the Sunday/Monday time frame...that would improve our chances
at severe weather. At the same time, the fcst soundings show a
formidable cap at least on Sunday, so it will be very difficult to
get much coverage of deep convection. The most likely place would
be southeast facing mountain slopes where differential heating
could be enough to break the cap, but it seems more likely that
we won`t on Sunday. The precip chances might be overdone over
northeast GA and southwest NC. The cap looks more breakable by
Monday, but the elevated mixed layer is gone for the most part and,
oddly, our precip probs actually drop. Widely scattered ridgetop
convection is expected again Tuesday afternoon. Shear parameters
are forecast to be rather weak, but a few pulse-type strong/severe
storms are possible each afternoon.


Key message 2: A cold front moving in from the northwest is
expected to bring better rain chances from Wednesday afternoon
through Friday, but probably not enough rain to make a dent in
the drought. Cooler temperatures return behind the front for the
end of the week.

By the middle of next week, the upper pattern will start to flatten
out again as short waves lift out of the western trof and flatten
the eastern ridge. The main wave will pass well to our north
on Wednesday while pushing a trailing cold front down from the
northwest across the OH River valley to the western side of the
mtns. Meanwhile, the persistent Bermuda High feature off the East
Coast will have had enough time to bring some moisture in from
the Gulf, leading to an increase in shower chances for the mtns at
least on Wednesday afternoon. That day will probably feel very much
like a typical summer day with the increased humidity. Uncertainty
increases after Wednesday with regard to where the front stalls and
when it lifts back northward, if at all, Thursday or Friday. The
guidance is divergent, so the model blend more or less smears out
above climo precip probs each day. At this time, there isn`t much
of an indication that we would have any significant chances for
severe weather, as the joint probability of sufficient buoyancy and
shear is very low in the model ensemble. Unfortunately, in spite
of how great the increased precip chances look, the probability of
getting more than an inch of rainfall on any given day is too low
to mention. That means most people won`t get enough rain late in
the week to dent the drought, though a few might be more fortunate.
Behind this front, temps cool down back below normal for Friday
and Saturday.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: VFR at all terminals through the forecast
period, with mostly high clouds. Light/variable wind overnight
will become SW with daytime heating by late morning, and then stay
that way through the evening, courtesy of sfc high pressure off
the Carolina Coast.

Outlook: VFR conditions expected to persist through the first
half of next week, except in mountain valleys, where as moisture
increases, the potential for morning fog/low stratus will increase
each night. Isolated diurnal convection is possible early in the
week, primarily across the mountains. An active cold front may
bring restrictions associated with convective precip from Wednesday
afternoon onward.

&&

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

&&

$$

PM