Rock Hill, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

354
FXUS62 KGSP 212006
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
Issued by National Weather Service Blacksburg VA
306 PM EST Thu Nov 21 2024

.SYNOPSIS...
Deep low pressure will pass across the Great Lakes into the
weekend, resulting in gusty northwest winds that will bring snow
showers to portions of the mountains through Saturday morning.
As low pressure departs on Saturday, high pressure will arrive
from the west that will bring a gradual warming trend into the
early part of next week.


.NEAR TERM /THROUGH FRIDAY/...
As of 150 PM EDT Thursday...

Keeping an eye on increasing cloud cover and deepening moisture
arriving from the northwest this afternoon as a disturbance
approaches from the Midwest region, rotating around an upper
level low passing across the Great Lakes. That stated, much of
western North Carolina into northern South Carolina is
experiencing abundant sunshine, with temperatures in the mid to
upper 50s. With our area sandwiched between deep low pressure to
the northeast and high pressure over the central US, winds this
afternoon remain generally from the west, with gusts in the 25
to 30 mph range.

Through this evening, chances for snow shower activity will
increase as moisture off of Lake Michigan arrives. Snow shower
activity will start off as light on-and-off bands this
afternoon and evening. The heavier bands will arrive after
sunset and will persist through the night, which is when the
highest accumulations will occur. With high pressure moving in
from the west on Friday, snow shower activity will begin to
diminish, though flurries flying through the air will remain
possible into Friday evening. No changes at this time with the
current Winter Weather Advisory. Snow will diminish quickly
further east of the advisory area in the downslope windflow.

The other concern through the period will be gusty winds given
the passage of deep low pressure across the Great Lakes region
through Friday. Gusts will remain up to 30 mph through this
evening, with locally higher gusts. Speeds will diminish
somewhat by sunset across the Piedmont to 10 mph or less, but
will remain gusty west of the Blue Ridge, possibly to 40 mph in
a few spots, as another wave of energy passes across the
Appalachians tonight.

The arrival of chilly Canadian air will push temperatures
tonight generally into the low to mid 20s for areas west of the
Blue Ridge, while lows further east will hold in the low to mid
30s. Expect cooler temperatures on Friday as well, again due to
the passage of upper level low pressure. Friday afternoon highs
will reach into the upper 40s to mid 50s east of the Blue
Ridge, but will hold in the low 40s to the 30s further west,
even struggling to reach above freezing in spots.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 200 PM EST Thursday...

Period starts off Friday night with lingering enhanced NW gradient
winds and some continued chances of upslope snow showers on the SW
extent of the departing strong upper low and wrap-around moisture
field mainly impacting the Blue Ridge. This should be tapering off
by Saturday morning as ridging builds in under NW flow aloft and the
mountains should gradually scatter out of the cold advection
stratocu.

Saturday high temps should start to rebound with generally 40s to
low 50s in the mountains and upper 50s to low 60s in the Piedmont
and with winds becoming more lax by afternoon. Sunday looks quite
pleasant as near zonal flow and continued ridging allows for temps
to moderate even warmer with many locations in the 60s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 230 PM EST Thursday...

The next main influencing feature will be an approaching elongated
front that loses phase from another upper low centered near the
Canadian border. This will allow for increased precip chances later
Monday into Tuesday as it pushes south and becomes more moisture
starved. With a rather warm airmass though stable the precip type is
expected to be just rain this time. QPF values look to be rather
light with most locations under a quarter of an inch. There looks to
be a shortlived break in precip late Tuesday, then moisture
advection kicks in again along the southern stream of the upper flow
with zonal to gradual amplification from the west Wednesday into
Thursday. Have slight to low chance pops for showers Wednesday then
increased chances Thursday. Thermal columns look to remain too warm
so expecting the liquid variety in this setup.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Expect VFR conditions for most terminals
through the 21/18Z TAF forecast period, with the exception
potentially for KAVL during Friday morning. A wave of energy
arriving from the Great Lakes will bring snow showers across the
Appalachian chain, with the highest chances occurring tonight.
Present indications are that precip will remain confined close
to the TN border, though for KAVL, confidence is moderate to
high that snow showers will impact visibilities in on-and-off
fashion as rounds of snow pass across the area. Winds will
remain breezy otherwise, generally from the west-northwest
through the TAF period, with gust in the 25 to 30 kt range.
Speeds will diminish overnight east of the Blue Ridge to around
10 kts, however gusts will remain stronger across the mountains
as another wave of energy passes across the region overnight.
Gusts in the 20kt to 25kt range can again be expected through
the day on Friday east of the Blue Ridge, and in the 25kt to
35kt range west of the Blue Ridge.

Outlook: Low pressure will depart on Saturday with high pressure
returning from the west. This will bring a gradual improvement
of flying conditions as the new week begins.

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Winter Weather Advisory until 7 AM EST Saturday for NCZ033-
     048>052.
SC...None.

&&

$$

SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...AB
LONG TERM...AB
AVIATION...NF