Simpsonville, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

789
FXUS62 KGSP 310253
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1053 PM EDT Sun Mar 30 2025

.SYNOPSIS...
Shower and thunderstorm chances through tonight into Monday as a
cold front approaches from the west. A few of these storms could be
severe. Dry high pressure returns Tuesday, resulting in well above
normal temperatures across the region late in the week.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
As of 10:15 PM EDT Sunday: We`ve still got a band of light to moderate
showers moving northward along and just north of the NC/SC border late
this evening. With little sfc-based instability still present, it is
doubtful that we`ll see anymore lightning tonight/overnight. Precip
coverage should continue to gradually dwindle over our area over the
next few hrs as the plume of deeper moisture moves further east. Any
lingering shower production will likely retreat to the SLY upslope
areas near the Escarpment while the convection associated with the
approaching cold front remains to our west. Hopefully areas around
the active fires will see some additional showers going into the
overnight.

Otherwise, for Monday, the larger-scale forcing looks adequate and
moisture deep enough to warrant PoPs ramping up into the likely to
categorical range by the afternoon. The latest near-term guidance
remains fairly stingy wrt pre-frontal precip coverage during the
morning hrs, especially outside of the mtns. Nonetheless, the central
and SW NC mtns and locations along the NC/TN border could get some
decent QPF thru the morning. Whether they see any lightning/thunder
that early looks unlikely. As for the severe potential with the main
line of convection that moves through during the afternoon and early
evening, our non-mtn zones remain under an Enhanced Risk area per SPC,
and our mtns are under a Slight Risk area. The main severe threat is
still damaging straight-line winds, with large hail being less likely.
In addition, brief tornadoes will be possible as well, especially over
our east and southeast zones. The latest CAMs still depict better storm
organization to our south and east as has been the case for several runs
now, but the HRRR does produce some fairly impressive-looking cells over
the I-77 corridor and our eastern-most zones. The main line of showers
and storms should move east of our CWA by roughly 00z, with a secondary
line of showers moving over the NC mtns during the evening hrs. This se-
condary line of showers should fizzle out as it moves east of the higher
terrain tomorrow night. High temps on Monday will top-out about 5 to 10
degrees above normal.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Key Messages:

1) Dry weather returns Tuesday with rain chances possible by midweek.

2) Above normal temperatures Thursday.

As of 155 PM Sunday: The cold front continues to move through the
area and should be crossing the CWA Monday night. After the FROPA,
high pressure returns and shunts rain chances on Tuesday. The
general synoptic flow turns more quasi-zonal into mid week before a
trough builds in across the Rockies and an amplifying ridge moves in
from the south. Previous forecasts had an area of low pressure
forming over the central CONUS and lifting northward, trailing a
cold front across the area. However, recent guidance from the
GFS/EURO both show a stout ridge expanding and persisting over the
area from about midweek onward. This is trending rainfall potential
even drier as the area of better lift/convergence is now off the NW
of the CWA. This does lower QPF response and PoPs down into the
slight chance range as confidence is decreasing for rain potential.
These height rises could shunt precip chances and bring temperatures
well above normal through the short term and into the next. One
positive note is southerly winds return Wednesday night and advect
more moisture, keeping RH values well above any critical levels.
Tuesday looks to be the driest day with RH values in the 25%-35%
range, but improving onward.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Key Messages

1) The forecast has trended drier, as a strong ridge builds across
the Southeast

2) Temperatures warm to well above normal through the period.

As of 200 PM Sunday: As was the case in the short term, guidance
from the GFS/EURO continue to trend toward an amplifying ridge over
the southeast through most of the forecast period. Southerly flow
remains dominate during the time, so moisture remains in the area.
The ridge axis pushes west a bit, shunting once again most of the
better precipitation chances off to the north. By Day 7, models hint
at the ridge starting to weaken, bringing back rain chances, but
this is highly uncertain since it`s a week away. Overall, guidance
continues to trend drier for the area, keeping needed rainfall away
once again. Given the moisture in the region, won`t rule out a few
scattered showers, so will keep slight chance PoPs for most of the
extended. Additionally, confidence is increasing that the area could
have temperatures in the upper 80s toward the end of the forecast
period depending on the strength of the building ridge. Overall,
expect well-above normal temperatures and little rainfall.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: A fairly broad area of sct moderate to heavy
showers is currently moving NE across most of our non-mtn zones.
We`ve seen a handful of lightning strikes from this activity in
the vicinity of our Upstate terminals over the past few hrs, but
with instability diminishing going forward, we`ll likely only see
showers for the rest of tonight/overnight. Otherwise, most of this
precip activity should also move east of our fcst area over the next
few hrs as the plume of deeper moisture moves east. Most of the near-
term guidance continues to spread low clouds/IFR cigs across most of
our area by midnight or so and keeps them in place into the early
afternoon. There`s also a decent chance that at least the Upstate
sites will see LIFR cigs overnight and into the morning. The mtns
appear more likely to remain in the MVFR range, but there`s still
a decent chance that KAVL will see IFR cigs thru the morning hrs.
Otherwise, the main line of showers and thunderstorms is progged
to move thru our fcst area during the afternoon and should be east
of KCLT by roughly 23z. As such, I have a 3 to 4 hour window of
prevailing SHRA with a TEMPO for TSRA for most terminals with some
lingering VCSH to end the taf period. Winds will remain SLY into
the morning and gradually become more SSW and then SW (with low-end
gusts) as the day wears on and the main front moves thru.

Outlook: Drying is expected on Tuesday. Some sct showers and their
associated restrictions will be possible on Wednesday and Thursday.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...JPT
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...JPT