346
FXUS62 KGSP 231731
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1231 PM EST Sun Feb 23 2025

.SYNOPSIS...
Dry high pressure remains over the region early this week. A warming
trend will continue, with temperatures above normal Monday through
Thursday. Rain is possible by midweek.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1226 PM EST Sunday: Sunny sky across most of the fcst area,
but some high thin clouds were on track to move across the srn
half of the area this afternoon based on the satellite trend. Don`t
think it will impact the high temps at this point. Note that many
dewpts were running lower than fcst still, so another downward
adjustment was made, bringing the RH farther down into the 20s
for much of the area outside the mtns for the afternoon.

Otherwise, general flow over the region remains rather zonal Sunday.
Out west, a disturbance in the pattern occurs and brings an area
of baroclinicity to the south of the CWA by Sunday night. This
means little to nothing in the sense that high pressure, though
weakened, still remains overhead. Dry conditions prevail and winds
remain very light and even calm at times. As for fire concerns,
the pattern of persistent high pressure brings light and mostly
southerly winds, helping to increase dewpoints a bit. RH values
should be closer to the 25%-30% range today for most of the NE GA
and Upstate SC areas.  With no rain on the horizon, fuel moisture
will continue to decrease, raising concerns for fires. As for
temperatures, expect the warming trend to continue with highs
reaching the upper 50s and lows around freezing.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 100 AM Sun: Shortwave trough tracks just south of the CWA on
Monday. While this feature will be associated with a warm front,
neither isentropic lift nor good moisture advection looks to make it
very far into our CWA, if at all. Furthermore, now that Monday is
within the range of some CAMs, their lack of response backs up the
mostly sub-slight-chance PoPs suggested by most other guidance. Some
moistening above 700mb Monday night may however bring a shot of cloud
cover. Cyclonic flow continues aloft and the next shortwave in
sequence looks to pass the Appalachians on Tuesday along with a very
weak cold front. These features also are moisture-starved, and the
front appears not to result in airmass change. Some moistening is
seen on 850mb progs with continuing NW flow near the TN border, but
said moisture is fleeting and no PoP appears warranted for that
either.

Temperatures continue to moderate, and thicknesses remain on an
upward trend thru the period. Max temps should be 2-3 above normal
Monday and then likely likely more than 10 above normal Tuesday.
Similar to previous expectations, dewpoints will remain dry but
mixing will be limited by a strong inversion aloft so values are not
likely fall to the bottom end of the guidance envelope as we see on
many warm days this time of year. Current thinking is that afternoon
values probably will fall a little below the NBM.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 230 AM Sunday: Flow turns quasi-zonal Wednesday between the
departing wave and the next, stronger one.  Temps are likely to be
similar to Tuesday`s although RH may be a little higher. The trough
will dive toward the area Wed night; it stands apart from the
early-week waves in having an attendant sfc cyclone and cold front.
Still some timing variation among the major models and ensemble
members, but most likely timing for the fropa will be Thu afternoon
to early evening.  PoPs remain in the solid chance range east of the
mountains in that timeframe, with likely values near the TN border.
CAA aloft will erode the longstanding subsidence inversion over the
area and small diurnally enhanced instability is depicted on the GFS
and some EC ensemble members. This well defined trough still is
expected to extend across the full latitude of the eastern CONUS as
it passes our CWA, and a fairly good slug of DPVA should accompany
the front along with 500mb winds of 70+ mph. 0-3km shear of 30-40 kt
may translate to a nonzero severe threat, particularly given the
strong forcing aloft, but shear vector orientation doesn`t look
ideal. A slight-chance thunder mention is being included Thu
aftn/evening. CAA on the back side of this system and lingering
moisture in the upslope layer result in snow chances Thu night and
Fri morning along the TN border.

Temps will return to near normal Thu night and Fri. Once again, flow
goes quasi-zonal only briefly before the next deep trough swings
across the East Saturday. Max temps trend a few degrees above normal
that day. The track of the sfc low is a bit further north and less
moisture return occurs, so PoPs are not warranted for most zones, but
another round of NW flow precip (at least partly snow) may develop
Sat night in the usual area.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR conditions at all terminals through
the TAF period, with only high clouds and light/variable wind,
as weak high pressure continues to influence the region in spite
of a short wave passing close to the south.

Outlook: Dry high pressure lingers through at least mid next week
with VFR conditions expected.

&&

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

&&

$$

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