Rock Hill, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

309
FXUS62 KGSP 220543
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1243 AM EST Sun Dec 22 2024

.SYNOPSIS...
Cold air will continue to filter into the area over the next couple
of days high pressure remains in control of the area. However,
temperatures are expected to trend back toward normal for Christmas
with more moisture returning to the area as well.

&&

.NEAR TERM /THROUGH TODAY/...
As of 955 PM EST Saturday: Forecast continues to be on track. Temps
are perhaps falling slightly slower than forecast, as winds haven`t
decoupled yet. But with clear skies (except for lingering stratocu
near the TN border) and expected weakening winds, will leave min
temps as is with the evening update.

Otherwise...Deep layer N/NW flow should persist through the bulk
of the period.  We`re already past the height of CAA, and that`s
reflected in the downward trend with respect to gusts across the
Piedmont and Upstate.  Broad troughing is still in place across
the eastern Seaboard, but heights will increase subtly now that
the central trough axis is east of us.  Most guidance now depicts
a weak shortwave pivoting across the southern Blue Ridge and into
the Upstate this evening, but it shouldn`t amount to much more
than perhaps some thin clouds over the Upstate the first part
of tonight.  These will disperse once the shortwave slides east
of the area after midnight...and most locations will see lows
in the lower 20s tonight.  That will make for a very cold night,
especially with winds never quite dying down (in fact, it looks
like based on model soundings, the boundary layer will never quite
decouple through sunrise).  So, we`ll be starting out cold on Sunday
morning, and highs tomorrow are expected to be a category colder
than today`s, despite clear skies and continuing high pressure.
RHs are expected to fall into the 30-35% range tomorrow afternoon,
but by the time this occurs, winds should have dropped off enough
to avert any serious fire weather concerns.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
As of 145 PM EST Saturday: Deep upper trough axis will be pushing
off the Eastern Seaboard as we move into the short term, and
confluent flow aloft upstream of the trough will allow the cold
surface high to slide over the Appalachians and wedge down the
eastern slopes Sunday night, continuing the well-below-normal
temperatures on Monday. No moisture attendant with the CAD so just a
cold dry day. The pattern flattens briefly during the day as a
shortwave digs in to the upper Midwest, inducing weak downstream
ridging over the Appalachians. GFS wants to develop a coastal wave
Monday night and ECMWF is a little weaker with this feature, but
both are indicating an increase in cloud cover towards the end of
the short term. Should have a much warmer day on Tuesday with flow
flattening aloft as the surface high shifts offshore bringing flow
back from the south.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 215 PM EST Saturday: The Midwest shortwave will work its way
east as we move into the extended, with a southern stream shortwave
digging into the Southern Plains, and a weak front extending between
the two. Very little deep moisture associated with this system and
GEFS solutions seem to agree, nevertheless enough general support
for some low-end pops late Christmas day into Thursday. Another
shortwave ejecting out of the Southern Plains toward the end of the
period might be slightly more interesting especially with another
surface damming high in place over the area, though temperatures
will not be particularly cold and mid-level ridging will keep the
best of the moisture deflected to our NW. Pops increase toward the
end of the period into the mid- to high-chance range. Temperatures
through the period remain above freezing for all but the highest
peaks so no real p-type issues to speak of.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Expect VFR conditions to prevail thru
the 06z taf period as broad sfc high pressure builds in from
the north. We could see some low-end VFR stratocu develop over
the SC Upstate overnight and into the early morning, but it`s
doubtful they would produce any restrictions. Otherwise, expect
mostly clear skies and light NE winds thru the period. Winds
will likely veer to a more ELY direction during the aftn/early
evening today. At KAVL, winds should remain NWLY thru roughly
mid-morning and then go light and vrb. They will eventually
favor a SLY direction by this evening with speeds of 5 kt or
less.

Outlook: Expect broad high pressure and mostly dry conditions to
persist thru early next week. Precipitation chances and associated
restrictions increase by mid-week.

&&

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

&&

$$

SYNOPSIS...TDP
NEAR TERM...ARK/JPT
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...JPT