534
FXUS62 KGSP 021848
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
248 PM EDT Thu May 2 2024

.SYNOPSIS...
Dry and warm high pressure moves off the Carolina coast as a
front approaches from the west then stalls over our region for
the weekend.  This front will result in periodic thunderstorms and
showers starting Friday and remaining through the weekend. A general
summertime pattern sets up early next week, which will likely
support scattered thunderstorm development each afternoon.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 237 PM EDT Thursday: A few small fair weather stratocu have
developed across the region this afternoon. Temp/dewpt trends
look good. What a nice day, courtesy of an upper ridge on the East
Coast supporting sfc high pressure to our east. No changes.

The upper ridge to our east will move slowly offshore tonight,
allowing moisture to move back in from the south/southwest toward
morning. A lead short wave lifting out of the trof well to our
west will move over the mtns after midnight, but minimal response
is expected through sunrise as forcing remains weak with this
feature. Clouds will increase, however, which will help to keep
min temps relatively mild. Friday looks to be a trend toward a
more active stretch of weather. With the upper ridge offshore,
we end up in a deep SW flow aloft that has several embedded short
waves, the first of which will linger across the region through
peak heating. The situation appears relatively benign, with precip
probs slowly ramping up from the west with likely over the mtns
and chances east of the mtns. We may get up to 1000-1500 J/kg of
sfc-based CAPE to work with in the afternoon, which will give us
the environment to support a few thunderstorms, but for now the
severe storm risk appears to be low. High temps should be on the
order of 5-10 degrees above normal.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 215 PM Thursday: A ridge of high pressure slides off the east
coast as an unsettled pattern sets up for the weekend. By the start
of the period on Friday night, a series of shortwaves traverses
toward the CWA. A well saturated profile is expected to enhance
rainfall chances by Saturday and into Sunday. However, the area will
be in a weak flow regime and any upper air support would be minimal.
Little if any DPVA appears in the GFS as the 500mb gradient remains
broad. This will limit the amount of thunderstorms that could occur,
along with minimal instability. At this time, a small amount of
muCAPE exists during the day on Saturday, which could be enough for
some lightning strikes and thunder. Strong storms could occur, but
confidence for the potential for severe weather is low. This could
change as Saturday gets closer and will continue to monitor closely.
Despite widespread showers expected. The QPF response is not
impressive with the Storm totals struggling to reach 1 inch between
Friday night and Sunday morning, with the somewhat higher amounts
east of the mountains. Temperatures on Saturday will be a tick or
two cooler than the past few days with most of the area reaching the
upper 70s. By Sunday, showers continue and start to taper off by the
end of the period, but at least chance PoP remains for Sunday. Winds
are expected to remain relatively light with low end gusts possible
in the eastern NC Piedmont on Sunday.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 220 PM Thursday: The general pattern remains similar at the
beginning of the extended period with a broad flow aloft and
shortwaves moving through. Meanwhile, out west, a trough begins to
develop and swing towards the central CONUS. Another, less
impressive shortwave over the central plains moves into the NE,
sending a ripple downstream toward the CWA. Guidance does keep a
deep layer of moisture remaining across the southeast, meaning PoPs
will remain elevated Monday before tapering off Monday night. By
Tuesday, a strong upper low swings northward over the Dakotas and
guidance from the EURO and GFS have a boundary extending toward the
CWA. The better forcing remains to the NW and far out of the CWA,
but this could change. Too much uncertainty exists with this system,
but showers and rainfall look to occur. This makes for yet another
unsettled pattern, but nothing that looks concerning in the way of
any severe weather at this point. High pressure could start to creep
back in toward the end of the period or mid-week, kicking up daytime
temps into the first 90s of the season.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Expect VFR conditions to prevail at all
terminals thru the late morning on Friday, as sfc high pressure
moves off to the east. Most places will see a few high-based fair
weather stratocu thru peak heating, with bases generally 050-060,
then those clouds will dissipate with sunset. Wind expected to
be light S to SE thru the afternoon, then light S overnight. Not
much chance of mtn valley fog again overnight because of a lack of
moisture. On Friday, moisture will return from the southwest well
ahead of our next cold front. Wind should be S. At this point,
it seems unlikely that any great chance of showers will reach the
terminals before the end of the period, except maybe the very end
at KAVL and also the very end at KCLT, because of the 30 hour.

Outlook: VFR conditions are expected thru most of Friday. More
numerous showers and thunderstorms and their associated restric-
tions are likely on Saturday and possibly into Sunday with the
passage of another cold front.

&&

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

&&

$$

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