676
FXUS62 KGSP 270012
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
812 PM EDT Fri Jul 26 2024

.SYNOPSIS...
Another round of scattered showers and thunderstorms are expected
today as a cold front tracks across the western Carolinas. Drier air
returns for the eastern two-thirds of the area for the weekend
before shower and thunderstorm chances increase again early next
week. Below normal temperatures will stick around this weekend into
early next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 5:55 PM Friday: Convection remains widely sct across our
area early this evening, with the only cells currently producing
lightning over the NC Piedmont. The latest CAM trends seem to be
more pessimistic wrt convective coverage through the rest of the
evening, but they still suggest that some activity could linger
thru late tonight and into the overnight.

Otherwise, the main story over the next 24 hours will be a brief
pattern shift that will feature a positively-tilted mid/upper trof
pushing the aforementioned boundary south across the forecast area.
The precip probs taper off this evening before the boundary passes
and the guidance keeps it quiet for the rest of the overnight. We
should retain plenty of moisture at low levels at any rate, which
could result in the development of low clouds and some fog in the
pre-dawn hours. Low temps will be close to normal. For Saturday,
the passage of the trof should allow some mid and upper level
drying, alleviating the recent flash flood threat that we have
had owing to lower precipitable water. The CAMs are fairly quiet
for the afternoon with a lack of mid/upper support and poorer
instability, which makes sense as a N/NW flow takes over in the
wake of the trof passage. Still, it`s hard to keep the showers and
storms from developing over the higher terrain with some heating,
so a chance will be kept over the mtns. High temps should be about
five below normal.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 230 PM EDT Friday: Dry high pressure will build into the
Carolinas Saturday evening into early Sunday leading to drier
conditions. Shower and thunderstorm chances look to increase, mainly
across the mountain zones, Sunday afternoon and evening as low-level
flow turns S`ly. With S`ly flow continuing into Monday, showers and
thunderstorms should return again across the mountain zones with
activity expected to spill east of the mountains. Any severe threat
looks to be low thanks to weak shear and instability generally less
thank 2000 J/kg. However, weak shear (~10-15 kts) allowing for slow
moving storms combined with convective chances gradually increasing
through Monday should allow the localized flooding potential to
return. High temperatures will remain a few degrees below climo
through the period, with lows remaining a few degrees above climo.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 245 PM EDT Friday: Upper troughing will be in place
over the Carolinas through the duration of the long term forecast
period allowing for widespread showers and thunderstorms each
afternoon and evening. This activity will keep the potential for
hydro concerns around through the period. Highs will remain near
climo to a few degrees below climo on Tuesday before climbing to a
few degrees climo Wednesday into Friday. Heat indices in the upper
90s to lower 100s will be possible each afternoon Thursday and
Friday. Lows will remain a few degrees above climo through the
period.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: I have VCSH for any lingering showers near
the Upstate terminals and at KCLT thru late tonight and into the
overnight. I keep a VCTS in the taf for the first few hrs for KHKY
and KAVL as they are more likely to see thunder. Otherwise, once
the shower activity diminishes, guidance suggests the redevelopment
of low clouds and patchy fog across the region. Cig restrictions
still appear more likely than visby restrictions thru the morning,
with all taf sites carrying MVFR cigs, with TEMPOs for IFR cigs
at KCLT and KHKY around sunrise. At present, the only sites that
have visby restrictions are KAVL and KHKY, and those are limited
to MVFR. Extensive cloudiness will likely slow the development of
convection on Saturday. This coupled with drier air spreading over
much of the fcst area from the north will limit precip chances.
Thus, the only taf site that currently mentions precip is KAVL.

Outlook: Some amount of drier air is expected to move into the
area from the north over the weekend. This will likely reduce
the chances for showers and thunderstorms and keep morning fog
and low stratus more restricted to the NC mtns.

&&

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

&&

$$

SYNOPSIS...AR
NEAR TERM...JPT/PM
SHORT TERM...AR
LONG TERM...AR
AVIATION...JPT