Area Forecast Discussion
Issued by NWS Greer, SC

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895
FXUS62 KGSP 030604
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
204 AM EDT Fri May 3 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 today and lingering through the weekend. A general
summertime pattern sets up early next week, which will likely
support scattered thunderstorm development each afternoon.

&&

.NEAR TERM /THROUGH TODAY/...
As of 200 am EDT Friday: The upper ridge to our east will continue
to move slowly offshore tonight, allowing moisture to move back in
from the south/southwest toward sunrise. 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 continue to
increase from the west, however, which will help to keep min temps
relatively mild.

Later today will see the beginning of 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.
Convective ingredients appear 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 very low...especially in light of weak
shear parameters. High temps should be on the order of 5-10 degrees
above normal.

&&

.SHORT TERM /TONIGHT 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 /06Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: VFR conditions are expected to persist across
the Terminal Forecast Area through the morning, with steadily
increasing high clouds expected. An upper level disturbance and
associated moisture plume will approach the area later today,
allowing for expansion of showers and thunderstorms, mainly during
the afternoon and evening. Scattered coverage of convection is
expected...at least across the western half of the area...warranting
Prob30s for -TSRA at most sites during the afternoon/early evening.
While some diminishment of convective coverage is expected this
evening...showers will remain possible well into the overnight
hours/early Saturday. Winds will generally be calm or light/
variable early this morning, becoming SW at 5-10 kts by
afternoon.

Outlook: Enhanced moisture will result in potential for scattered
showers, as well as cig/visby restrictions early Saturday. A weak
front is expected to become stalled in or near the area Saturday
through early next week, resulting in a period of active/mainly
diurnal convective weather each day. There will also be the
potential for restrictions associated with widespread fog and/or low
clouds each morning.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...JDL/PM/TW
SHORT TERM...CP
LONG TERM...CP
AVIATION...JDL