Simpsonville, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

794
FXUS62 KGSP 220516
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1216 AM EST Sat Feb 22 2025

.SYNOPSIS...
Dry high pressure will control our weather through the weekend
and into next week. A warming trend will begin this weekend that
should bring temperatures back above normal early next week.

&&

.NEAR TERM /THROUGH TODAY/...
As of 1215 AM Saturday: No major changes to the forecast as all is
quiet and calm.

Otherwise, the weather should be fair and quiet over the next 24
hours, and not quite as cool as the past 24 hours. A continental sfc
high over the mid-MS Valley region this afternoon should get pushed
overhead tonight with a flat upper ridge aloft, and then off to the
east on Saturday as a dampening short wave approaches from the west.
Expect good radiational cooling conditions overnight with clear sky
and wind going calm or light/variable, but the modifying air mass
will keep low temps no colder than this past morning, and probably a
few degrees warmer. That, combined with the light wind, should keep
our apparent temps far enough above Advisory criteria. The
approaching short wave on Saturday will be moisture-starved with
relatively weak forcing, so the main influence will be to increase
the mid/upper clouds for the afternoon hours. That means high temps
will probably only be able to climb five degrees at best above the
highs today. The lack of warmup will help to keep the RH from
bottoming out in the afternoon, and probably keep it in the upper 20
percents.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
As of 250 PM Fri:  A mid-level shortwave trough that is currently
over the Central Plains this afternoon is forecast to track
eastward, passing through the region Saturday evening. There is a
surface reflection of the disturbance as a weak cold front that
moves through the area at night. This system is moisture starved and
will provide little impact to our sensible weather aside from some
high clouds streaming through.

Surface high pressure builds in quickly behind the front late
Saturday night and remain overhead through Sunday.

Another upper shortwave trough over the Four Corners region of the
SW CONUS will move eastward, tracking along the Gulf Coast region.
This system looks to tap into some Gulf moisture, but it is expected
to pass far enough south to keep the forecast area dry Sunday night
and Monday (PoPs are less than 5%). Southerly return flow around the
departing high will yield moderating temperatures with highs in the
lower to mid 60s Monday afternoon.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 250 PM Fri:  A dry weather pattern continues into at least the
first half of the week as the region remains situated in mainly
zonal flow near the base of the large-scale trough that is
positioned near the US-Canada border. At the surface, the next in a
series of weak cold fronts will approach the area from the west on
Tuesday. Backed flow ahead of it will allow the warm sector to
become even further established. Highs in the upper 60s and lower
70s are forecast for Tuesday, which will likely be the warmest day
of the week.

The aforementioned dry cold front moves through late Tuesday,
followed by high pressure returning for Wednesday. Post-frontal CAA
is meager, so temperatures on Wednesday should only be a couple of
degrees cooler than Tuesday (but still around 10 degrees above
normal).

The high should quickly retreat off the eastern seaboard by late
Wednesday in response to yet another cold front approaching from
west. The system looks more potent than its predecessors and should
provide our next chance for precipitation with it. Cluster analysis
of the LREF shows mainly a timing disagreement among the global
ensemble members. Low chance PoPs exist in the forecast from late
Wednesday afternoon through Thursday evening owing to the
uncertainty in timing of the front and not because an extended
period of rain is expected.

Colder air returns behind the cold front, but it will lack the true
arctic cold air like yesterday`s fropa. Temperatures may
sufficiently cool to produce snow showers in NW flow in the
mountains near the NC-TN border Thursday night.

&&

.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: VFR conditions prevail at all terminals
through the forecast period. Winds become light to calm tonight for
all sites with winds picking up out of the southwest by mid morning
Saturday. No restrictions to vsby/cigs for the period as high
pressure remians overhead. High cirrus is expected to stream across
the region Saturday afternoon.

Outlook: Dry high pressure lingers into early next week with VFR
conditions.

&&

.FIRE WEATHER...
Lighter winds and lower RH values (25%-30%) today for counties in
Northeast Georgia. Though temperatures are expected to be cool,
additional drying during mixing this afternoon will contribute to
lower fuel moisture. These combined factors raise fire danger
concerns.

&&

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

&&

$$

SYNOPSIS...PM
NEAR TERM...CP/PM/TW
SHORT TERM...JK
LONG TERM...JK
AVIATION...CP
FIRE WEATHER...