Spartanburg, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

034
FXUS62 KGSP 291956
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
256 PM EST Wed Jan 29 2025

.SYNOPSIS...
High pressure builds in Thursday, as low pressure develops over
the southern Plains. An associated cold front will cross the
area Friday, bringing widespread showers across the area. Drier
and warmer weather expected this weekend into the early part of
next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 2:25 PM EST Wednesday: Other than some streaks of thin cirrus,
we remain mostly clear across the fcst area. Wind gusts have picked
up across our area over the past few hrs with numerous sites currently
reporting gusts in the 20 to 30 mph range, with the strongest gusts
still over the northern NC mtns. I still expect winds to begin to
weaken by the early evening with lower-end gusts likely to linger
over the NC mtns well into tonight. Temps should cool a fair amount
tonight/overnight, yet lows are expected to remain about a category
above normal for late January.

Otherwise, broad upper trofing will slowly move off the New England
Coast this evening and early Thursday, while a large, closed h5 low
lingers over the far SW CONUS. In response, heights steadily rise thru
the near-term period as upper ridging builds from the south. At the
sfc, weak high pressure will persist just to our SW this evening and
shift eastward on Thursday with the high moving off the Atlantic Coast
Thursday evening. At the same time, a robust low will begin to develop
over the southern Plains and lift a warm front over our area Thursday
afternoon/evening. The period should be dry for most of our CWA with
precip chances increasing over the mtns and far NE Georgia tomorrow
aftn/evening in response to the warm front lifting over the area and
low-lvl winds becoming SELY. Any QPF that does fall should be minimal.
In addition, the thunder/lightning potential appears to be essentially
zero thru early Friday with no sfc-based CAPE expected over our area.
With increasing high clouds spreading over the region on Thursday tem-
peratures should moderate some, but highs will still top-out 1 to 2
categories above climatology. With weaker winds expected tomorrow,
dewpts should not mix-out as much and minimum RHs should not get as
low. Thus, we shouldn`t have any fire wx concerns.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 230 PM EST Wednesday: Southern stream upper low will
open up and get absorbed into the prevailing northern stream
westerlies Thursday night into Friday. As the resultant trough
cross the region it will be positively tilted with most of the
better forcing tracking by to our north. The low-level jet will
be 50-60 kt, with WAA likely producing a low cloud deck and spotty
showers, mainly in the mountains Thursday night thru early Friday
morning. Then a cold front will bring a line of showers across
the forecast area. Guidance still showing no sbCAPE, but the NAM
does show a sliver of 100-200 J/kg of MUCAPE. Very high shear will
accompany the showers, with 0-6 km bulk shear over 80 kt. Given
such little instability, the severe threat still looks low despite
the shear. The forecast area will be in a warm sector of the low
pressure system, crossing to our north. So temps will be above
normal. Unless breaks in the clouds can produce some differential
heating, not expecting any boundaries to focus/enhance shear for
tornadoes. The showers may produce some heavy downpours, but the
line looks too progressive and narrow for much of a heavy/excessive
rain threat. Models are in pretty good agreement on the timing of
the line from west to east mainly from late morning to late aftn
Friday. By early evening, the front and associated precip should
be pushing east of the forecast area. There may be a few NW flow
showers Friday night, but temps will likely be too warm for anything
but rain/drizzle. Lows will be mainly in the upper 30s to lower 40s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 200 PM EST Wednesday: Quasi-zonal flow across the CONUS is
expected to start the medium range, and is expected to persist
well into next week. This pattern will keep the track of storm
systems across mainly the northern tier of the U.S., resulting in
dry weather for our area. The air mass slipping in behind Friday`s
fropa will be mild, with reinforcing cooler air slipping in from the
north Sunday, as high pressure tracks across the Northeast. Warm
southwesterly to westerly low-level flow will allow temps to warm
well above normal, with highs approaching 70 degrees in portions
of the Piedmont on Monday. Guidance starts to diverge a bit by
next Tuesday, with the GFS bringing a cold front in from the NW,
with potential showers in the mountains. But the ECMWF and Canadian
keep the area warm and dry thru midweek.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere: Expect VFR conditions to prevail at all
terminals thru the 18z taf period. Other than some thin cirrus,
skies should remain mostly clear into the evening. High clouds
will gradually increase from the west on Thursday, yet bases
should remain above 10k ft or so thru the end of the period.
Gusty winds will be the main concern this aftn/evening, with
sites outside the mtns remaining SW to W this aftn and even-
tually going north of W this evening with speeds weakening.
Winds will go light and vrb to calm overnight and eventually
pick up from the SE by the end of the period tomorrow. At KAVL,
winds will remain N to NW thru tonight and into the overnight
with speeds/gusts weakening this evening. They are expected to
go light and vrb early Thursday morning and then pick up from
the SE by the end of the taf period.

Outlook: Restrictions may return Thursday night ahead of an
approaching frontal system, which is likely to bring periodic
restrictions on Friday. VFR conditions are expected to return
on Saturday, however additional restrictions can`t be completely
ruled out over the weekend.

&&

.FIRE WEATHER...
Windier and still warmer conditions are expected today, and
fuels will have had another day to dry to go along with 20%-25%
RH values. IFD criteria will likely be met in portions of NC, from
the mountains near the Blue Ridge Escarpment eastward through most
of our Piedmont zones. After coordination with NC land management
agencies, an IFD has been issued for much of the day today.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Wind Advisory until 6 PM EST this evening for NCZ033-049-050-
     501-503-505.
     Increased Fire Danger until 6 PM EST this evening for
     NCZ035>037-052-053-056-057-059-063>065-068>072-082-
     501>510.
SC...None.

&&

$$

SYNOPSIS...ARK
NEAR TERM...JPT
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...JPT
FIRE WEATHER...ARK