031
FXUS62 KGSP 301840
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
240 PM EDT Tue Apr 30 2024

.SYNOPSIS...
Dry and warm high pressure builds across the region Wednesday
through Thursday, before another active frontal system moves in
Friday and lingers through the weekend. The next front approaches
toward the middle of next week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 235 PM EDT Tuesday: Seeing a large number of showers
developing ahead of a well-defined short wave seen on water vapor
imagery just west of the mtns. Not many thunderstorms out there
yet, but it stands to reason that with perhaps 500-1000 J/kg of
sfc-based CAPE to work with, we will see a few, most likely in
northeast GA where we might have the potential to get more breaks
in the cloud cover, and then in a better buoyancy plume over
the southeast fringe up to metro CLT . Poor lapse rates and weak
shear suggest the risk for anything severe to be relatively low,
and rainfall amounts should also be modest.

For tonight, the short wave should make steady eastward progress
and should be east of the fcst area by late evening, taking the
shower chances with it. If we can get enough coverage of rainfall
across the region through sunset, it could set the stage for some
widespread fog as mid/upper levels clear off behind the upper
wave. Hard to say if this will be anything more than locally dense,
but it will be something we will have to monitor later tonight. Not
a big push of cooler air behind this system, so low temps will be
around a category warmer than normal. In the wake of that system,
an upper ridge builds to our west on Wednesday with sfc high
pressure building over the mtns to dry us out, though the min RH
does not look like a problem. High temps will rebound 5-10 degrees,
and about five above normal, under sunny sky.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 1215 PM Tuesday...We are still expecting the atmosphere to
remain suppressed on Thursday as upper ridge axis is still progged to
build atop the SE CONUS and boost piedmont maximum temperatures into
the middle 80s.  Lower lvl return flow, well downstream of elongated
weak ohio valley front, will moderately nudge sfc dwpts upward on
Friday.  In combination with an approaching weak southern plains
s/wv, a smattering of showers and a few tstms are probable,
especially in the mountains on Friday.  Giving the weak
thermodynamic profiles progged, at this juncture, the bulk of storms
which develop on Friday are expected to be of the garden variety.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 115 PM Tuesday...Given the quasi-zonal and wavy pattern
setting up atop the region for the weekend, it is difficult to get
into specifics with respect to shower cvrg for any specific period,
but overall, unsettled is a good way to describe the sensible weather
for Saturday and Sunday.  Given the moist profiles expected,
numerous showers and embedded diurnally enhanced tstms are probable
at some point on both Saturday and Sunday. Thanks to clouds and
shower chances, maximum temperatures will be back closer to the
early May climo. Downstream of rather vigorous looking plains
cyclone, ridging will once again strengthen atop the SE CONUS early
next week.  What is means is a return to piedmont mid 80s by day 7
along the daily shower or tstm chances lowering to below climo.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Seems a bit hard to pin this one down
because the coverage and intensity of showers looks unimpressive
on the radar and in the latest model guidance, but we still have a
high probability of getting convection at all terminals. Starting
out VFR everywhere with a S or SW wind. Based on the radar trends,
will use a TEMPO this afternoon to hold any restrictions and have
opted for showers everywhere but KAND. Meanwhile...KCLT will be
the one to watch, with some TSRA well to the SSW but heading in
that direction. The passage of a short wave aloft should take
the shower activity eastward thru the early evening to the point
where it will end shortly after sunset in the east. Thereafter,
just some residual mid level clouds. The big wildcard in the
forecast comes in the pre-dawn hours, with guidance now indicating
widespread fog restrictions, though not at KCLT or KGSP. This is
plausible with the afternoon showers then some clearing overnight,
but will approach this cautiously outside the mtns. So for now we
keep VFR at KCLT/KGSP, but hit KAVL fairly hard with some IFR at
daybreak. Whatever happens, it should mix out quickly after sunrise.
After that, VFR and mostly clear with a light N to NE wind.

Outlook: VFR through Thursday and into Friday. More numerous
showers and storms with related restrictions are expected on
Saturday ahead of a cold front.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...PM
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...PM