Rock Hill, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

912
FXUS62 KGSP 221056
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
556 AM EST Mon Dec 22 2025

.SYNOPSIS...
Dry high pressure builds into the area today, bringing temperatures
near normal to start the week. A warm front will lift northeast
through the area Tuesday, bringing small rain chances to the
mountains and an unusually warm air mass for late December to the
region. Expect dry conditions elsewhere, and well-above normal
temperatures for the Christmas holiday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 555 am EST Monday: The upper flow pattern will continue to
steadily amplify during the near term as a ridge builds strongly
across the Rockies and Great Plains. The pattern will nevertheless
remain quite progressive, and the center of very dry surface high
pressure is forecast to move from the central Appalachians early
this morning to Cape Hatteras by the end of today. Low RH/Fire
Weather will therefore be our primary near term concern. Surface
mesonet obs reveal dewpoints in the single digits with even
some sub-zero readings in spots across the high elevations this
morning...so there is plenty of very dry air available to mix to
the surface later today...and minimum RH is expected to bottom out
in the 15-20% range across much of the forecast area. Winds will
be a non-issue, but a Fire Danger Statement was issued earlier
for our GA zones...where FDS criteria are lower. Max temps today
will be very close to climo...the last day they will be anywhere
near normal until at least early next week.

The next in a series of speed maxima will approach the Great Lakes
from the Canadian Prairie late tonight into early Tuesday, resulting
in development of a warm advection pattern and shallow moisture
return across our region by around daybreak Tuesday. Moisture will
be too shallow and the near-surface layer too dry to support much
in the way of noteworthy PoPs, but token 20% probabilities are
advertised by daybreak across the NC counties bordering TN. Min
temps will be 3-5 degrees above climo...with lows likely occurring
early in the night (especially across the mountains) before the warm
advection kicks in. This warming should preclude any precip-type
concerns...in the off chance that precip does develop.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 1130 PM EST Sunday:

Key Message: Warming trend ramps up through the middle of the
week, with small rain chances in the NC mountains, mainly near
the TN border.

A weak frontal boundary will slip into the area Tuesday under an
amplifying flow aloft. An increasing pres gradient along with a
decent W/NW 850 mb flow should support breezy conditions across
the area, with highest gusts in the NC northern mountains. Gusts
are not expected to approach advisory criteria. Upslope flow may
squeeze out a few light rain showers near the TN boarder. But
downsloping should keep the rest of the area dry. The front lifts
back north as a warm front on Wednesday, with just some increase
in clouds expected in the aftn thru Wednesday night. Temps will
warm to about 5 to 10 deg above normal Tuesday, and about 15
degrees above normal on Christmas Eve. These fcst highs Wednesday
are within a couple degrees of records for GSP and CLT climate
sites. (See climate section below for more details).

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 1205 AM EST Monday:

Key Message: Well-above-normal temperatures for the Christmas
holiday, continuing into the weekend.

An upper ridge will continue to build with an axis over the lower to
mid-MS Valley region Thursday. The ridge will then begin to flatten,
but the axis will shift over the Southeast Friday. The latest
medium range guidance then diverges on what the ridge will do over
the weekend, with some retrograding the high (like the 00z GFS),
or digging a deep trough over the central CONUS (like the 21/12z
ECMWF). At least through Friday, guidance is in very good agreement
on anomalously warm air spreading in across the area from the west,
with downslope flow helping enhance max temps even further for
the Piedmont. Latest fcst highs are into the upper 60s to mid 70s
east of the mountains for Christmas day and the day after, which is
within a few degrees of records (see climate section below). Some
moisture may brush the NC mountains from the west Friday, but
overall, dry weather is expected to continue thru Saturday. Models
seem to be backing off any cool-down for Saturday, as well, with
yet another day of near-record highs possible. We may see a pattern
change begin to unfold with a stronger front cross the area Sunday
and a cool-down into early next week. With such warm temps ahead
of the front, no wintry precip types are expected. And the air
mass ahead of the front doesn`t look appreciably moist/unstable
for any severe weather threat or much in the way of QPF.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR conditions are forecast to persist
through this TAF cycle. Periods of mostly thin high clouds are
expected through the afternoon and evening, with the potential for
lower clouds increasing toward daybreak Tue in response to moisture
return and increasing lift. MVFR cigs can`t be ruled out after ~09Z
Tue, but this is far from certain, and low clouds will be held in
the 040-060 range for the time being. Light NE winds this morning
will veer toward the ESE early in the afternoon, becoming
light/variable during the evening. Winds will begin to pick up out
of the SW at 5-10 kts circa 12Z Tue.

Outlook: A weak front will bring low-end chances for rain and
associated restrictions Tuesday into Wednesday, mainly across
the mtns. Mostly dry, VFR conditions should prevail thru the end
of the week, outside of possible patchy mtn valley fog and low
stratus each morning.

&&

.CLIMATE...
RECORDS FOR 12-24

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      72 1955     17 1906     59 2015     -5 1983
   KCLT      73 2015     29 2022     63 2015      6 1983
                            1906
   KGSP      71 1964     28 2022     61 2015      7 2022



RECORDS FOR 12-25

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      71 2021     14 1983     59 2015     -7 1983
   KCLT      77 1955     22 1983     63 2015      4 1983
   KGSP      78 1955     22 1983     61 2015      6 1983



RECORDS FOR 12-26

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      78 1971     17 1902     55 2015      0 1983
   KCLT      77 2021     27 1983     58 2015      6 1983
                                        1964
   KGSP      76 2021     28 1983     62 1987      5 1985
                2015        1980



RECORDS FOR 12-27

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      72 1971     19 1902     59 2015      3 1925
   KCLT      72 2021     22 1892     65 2015     15 1970
                2015                                1948
                1971                                1925
   KGSP      75 1971     29 1925     64 2015     12 1925

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Increased Fire Danger from 10 AM EST this morning through this
     evening for GAZ010-017-018-026-028-029.
NC...None.
SC...None.

&&

$$

SYNOPSIS...ARK
NEAR TERM...JDL
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...JDL
CLIMATE...GSP