Rock Hill, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

373
FXUS62 KGSP 061053 CCA
AFDGSP

Area Forecast Discussion...CORRECTED
National Weather Service Greenville-Spartanburg SC
653 AM EDT Sun Oct 6 2024

.SYNOPSIS...
Warm and dry conditions will persist until a cold front tracks
across the region Monday. Following the front, below-normal
high temperatures will occur Tuesday through Friday, along with
virtually zero chance of rain. Tropical Cyclone Milton will move
across Florida in the middle of the week, remaining well to our
south and having minimal impact in our area.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 624 AM EDT Sunday: No major changes this morning.  Winds have
stayed elevated enough to prevent more widespread fog coverage
across the mountains.  Still, some valleys have clearly visible fog
in place, which should last until sun-up, then quickly scatter out.

Today`ll be clear and dry, as a suppressed upper pattern inhibits
any chance of rainfall.  High pressure will continue to drift
eastward to our north, and winds will stay predominantly north
through much of the day, flipping around to the SW late this
afternoon and evening.  Highs will climb into the upper 70s in NC,
and the lower 80s in the SC Upstate and northeast GA.  Tonight,
a weak cold front will arrive from the west, but still appears
too dry to prompt mentionable PoPs; the only impact will be a wind
shift to the NW overnight, and some breezier conditions leading
up to daybreak Monday.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 130 AM Sun: Cold front associated with Canadian low pressure
will push southeast across the area on Monday. There still appears
little opportunity for moisture return in our CWA prior to the
fropa, given the dry East Coast high having been in place for
a day prior to its arrival, and low-level flow veering to NW
by daybreak Mon.  Dewpoints will trend lower by afternoon over
most of our area, despite temps trending warmer in much of the
Piedmont as a result of downslope flow. The mountains will see
slightly cooler max temps compared to Sunday. Vertical profiles
will remain dry and subsident aloft over most if not all of the
CWA, so this decrease in dewpoints should further hinder convective
development. Some moistening does manage to occur in the Midlands,
if not our far southeastern zones, and that appears the driver
for late day or evening PoPs just south and east of our CWA.
Chance of PoP still will be kept below slight-chance, or around
10%, in our southern zones; near-zero PoPs are warranted for the
northern half of the area.

The front should settle south of the area Monday night. Remaining
PoPs will diminish to essentially zero and remain so through
midweek. Crisp fall air will spread through the CWA, with
overnight mins falling into the 40s across the mountains and 50s
elsewhere. Dry sfc high will expand into the lower MS Valley and
Southeast over the subsequent 24 hours, possibly centering in
the Ohio Valley by late Tuesday.  Piedmont highs will be as much
as 10 degrees cooler Tuesday; mins Tue night likely will reach
the 40s in the Piedmont I-40 corridor and at least trend a little
cooler elsewhere outside the mountains. Some cirrus cover may ride
up from the south at that time, as Milton ejects high altitude
moisture into GA/SC, and jet streak amplifies at the base of the
upper trough. Without that cirrus, radiative cooling would appear
likely to result in some 40s further south.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 200 AM Sun: The continental sfc high should continue to
gradually move toward the East Coast through Friday following the
upper low and surrounding trough; dry northerly flow will continue
into the CWA so cool temperatures will persist through the rest of the
period.

The deterministic runs and the vast majority of ensemble members still
show Milton moving across the Florida Peninsula Wed night, with no
precip impact over our CWA, and possibly all of SC for that matter.
Between it and the sfc high, a respectable northeasterly gradient wind
of about 30 kt develops at 925 mb, but CAA currently appears
insufficient to maintain a mixed layer which would allow that to
result in sfc gusts overnight. Some gusting upwards of 20 kt is likely
during the day Thursday in the Piedmont.  The stronger wind and some
CAA should make Thursday the coolest day of the period. As winds calm
and remaining cirrus clear, Thursday night likely will be the coolest
night of the period as well.  That said, even looking at the lower
percentiles of guidance, it is currently doubtful we will be cool
enough for frost.  Heights rise Fri-Sat as upper trough moves out into
the Atlantic and sfc high shifts south in turn; max temps return to
about normal Saturday.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Mostly VFR conditions continue in the 12z TAF
period, as high pressure spreads across the region.  Some ongoing
fog across the mountains has only intermittently affected KAVL thus
far, and should scatter out quickly after daybreak.  It`s looking
increasingly likely we won`t see restrictions develop at KHKY as
previously expected.  Winds will be light and out of the NE most
of the day, becoming more S this afternoon and evening.  Sky cover
will remain too low to warrant ceilings through Sunday night.

Outlook: Dry, VFR conditions are expected thru early next week.
Fog/low stratus will be possible overnight and each morning,
mainly in the mtn valleys.

&&

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

&&

$$

SYNOPSIS...Wimberley
NEAR TERM...MPR
SHORT TERM...Wimberley
LONG TERM...Wimberley
AVIATION...MPR