358
FXUS62 KGSP 220154
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
954 PM EDT Fri Mar 21 2025

.SYNOPSIS...
Dangerous fire weather conditions continue through the weekend as
dry air and gusty winds develop each afternoon. Another cold front
crosses the region Monday bringing a chance for rain. Dry air
returns behind the front, with the potential for additional fire
weather issues afterwards.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 930 PM EDT Friday: Grids look mostly good for the late evening
update tonight. Only some tweaks to hourly trends and sky grids as
cirrus moves through over the next several hours.

Otherwise, surface high pressure continues to build in as a weak
ridge moving overhead. All precip chances are shunted with strong
subsidence aloft, increasing fire weather danger across the entire
CWA. For Saturday, similar setup as today, but with a weak cold
front approaching the area. This increases wind gusts along with the
already dry air in place. Modeled soundings show a very deep mixing
layer up to the 700mb level, so guidance may have a difficult time
bottoming out the RH values. Given the anticipated higher winds and
very low RH, combined with very dry fuels, a Red Flag Warning will
be in effect for most of the CWA from 11am through 8pm Saturday.
Temperatures today are cooler but quickly rebound tomorrow.
Overnight temps across the mountains hover near freezing.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of midday Fri: Transient high pressure will cross eastern GA
and the Carolinas Saturday night. Cold front will stall across
the area early Sunday and quickly reactivate as a warm front as
sfc/upper trough approach from the west. SW return flow will lead
to a rebound in PBL moisture compared to Saturday, and stronger
subsidence inversion should limit diurnal mixing as well.  However,
temps will be similar to Friday`s if not a little warmer across
the Piedmont, and a few degrees warmer over the mountains. So
despite the higher dewpoints, RH will only improve a few percent on
account of the warmer temps and still will be below 30 percent in
many areas. Breezy conditions are expected during the afternoon,
albeit with gust potential limited by the inversion, but wildfire
danger still will be of some consideration particularly in light
of dry fuels.

The cold front associated with the passing trough will cross the
southern Appalachians early Monday and should exit the CWA to the
east by late afternoon. The front will bring PWAT values briefly
near one inch, and guidance develops decent upward vertical
motion with the WAA immediately ahead of the front, even though
dynamic support is not very impressive. A wetting rain of 0.10"
storm total looks likely in the mountains near the TN border,
decreasing toward the east where downslope will be a factor, but
still 50-60%. Temps will fall back a few degrees in the mountains
due to earlier arrival of the front, but the remainder of the area
will remain warm similar to Sunday. Drying dewpoints again can
be expected in the wake of the front, resulting in the mountains
seeing RH values fall below 30 percent during peak heating. Wind
gusts Mon aftn probably will be at least as much as Sunday`s;
the only offset to fire wx threat will be if the wetting rain
does materialize. RH probably will not reach critical values in
our southeast zones with drier air not arriving until evening.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 215 PM Fri: Weak high pressure moves across the Southeast
Monday night with light winds and mostly clear skies allowing for
temperatures to cool back to about normal. We then more or less see
the early-week evolution repeat Tuesday through early Wed, albeit in
an even less strongly forced fashion. The return flow appears less
of a factor and dewpoints look unlikely to rebound appreciably after
their drop Monday evening; with similar temperatures RH will remain
critically low. No better than low chance PoPs are expected late
Tuesday to early Wednesday preceding the front, given even broader
trough aloft and the lesser moisture advection preceding it. In
the wake of the front, windier conditions are expected Wednesday,
still with low RH; winds will be lighter on Thursday as stronger sfc
high arrives from the west, under slightly cooler temps. Afternoon
temperatures will remain above normal owing to generally abundant
sunshine and alternating periods of downslope NW flow or light SW
return flow. Any mitigating effect of the rainfall circa Monday
very well may be long gone by Wed-Thu and thus the takeaway, as
previously advertised, is that fire weather will remain at the
forefront of our concerns through at least Thursday of next week.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: VFR through the period with primarily a wind
forecast. NW winds will continue to diminish and back to the SW this
evening, generally remaining between 5-10kt overnight for most sites
except KAVL where weaker surface winds will allow for some LLWS
briefly around sunrise before mixing increases. A dry cold front
will cross the area tomorrow with winds again veering W and NW
through the day and gusts picking up after 14/15z. Timing for NW
winds at KCLT at 23z, with gusts dropping off shortly thereafter.


Outlook: Dry high pressure and VFR continue through the weekend.
Rain and associated restrictions may return on Sunday night
into Monday with a cold front.

&&

.FIRE WEATHER...
Very dry air remains over the region today as high pressure settles
over the Deep South. RH values below 20 percent are expected across
most of the CWA. Although winds won`t be nearly as strong, the dry
fuels and very low RH warrant another Fire Danger Statement across
most of the area through this evening. The only exception are
counties along the TN/NC border as earlier snow showers reduced fire
danger. RH values should also be in the mid to upper 20 percent
range for all but portions of the valleys. Saturday looks similar in
the way of RH values, but with a cold front crossing the area and
increasing winds, fire danger will remain a high concern.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Red Flag Warning from 11 AM to 8 PM EDT Saturday for GAZ010-
     017-018-026-028-029.
NC...Red Flag Warning from 11 AM to 8 PM EDT Saturday for
     NCZ035>037-053-056-057-059-062>065-068>072-082-501>510.
SC...Red Flag Warning from 11 AM to 8 PM EDT Saturday for
     SCZ008>014-019-101>109.

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/TDP
SHORT TERM...Wimberley
LONG TERM...Wimberley
AVIATION...TDP
FIRE WEATHER...