400
FXUS62 KGSP 052340
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
740 PM EDT Sun May 5 2024

.SYNOPSIS...
The weather pattern will have a summerlike look to it through
Wednesday, keeping scattered thunderstorm chances around each
afternoon. A strong cold front will approach out of the west on
Thursday before tracking across the western Carolinas on Friday,
leading to better coverage of thunderstorms towards the end of the
workweek. Highs will remain above normal through the workweek but
will climb well above normal Tuesday through Thursday.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 619 PM EDT Sunday: A quiet Sunday afternoon for the most
part, as a band of convection makes its way off the NC Blue Ridge
Escarpment.  Much of this activity is struggling to even produce
lightning...limited, perhaps, by poor synoptic forcing and a
lack of any discernible triggering mechanism.  DCAPE has somewhat
undershot prior forecasts due to a lack of dry air aloft that was
indicated in last night`s forecast soundings.  So, severe risk
continues to look low, although there`s enough instability that a
stray strong storm can`t be ruled out.  CAMs still look unimpressed
by the current setup, with virtually all the guidance except the
NSSL-WRF now depicting the band dissipating before making it to
the I-77 corridor.

Convection diminishes this evening but a short wave and occluding
cyclone, with associated remnant warm conveyor belt/moisture plume
is forecast to move in from the west toward daybreak. The guidance
has slowed the progression of this feature, limiting better shower
chances to the mountains. Show these trends in the hourly PoP
forecast. Lows will be around 10 degrees above normal.

Guidance shows the short wave/frontal feature crossing the area
on Monday with an increase in PoP through the day. Have continued
this trend in the forecast as well. The increase in shear forecast
seems likely given the stronger winds moving in with the feature,
but the instability increase on some models is more uncertain. This
is due to the development of morning cloud cover limiting heating,
and better overall precip chances. Therefore, while there will be
scattered thunderstorms, the chance of severe storms looks to be
limited unless better instability actually develops. Highs will
be a few degrees above normal.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 1220 PM EDT Sunday: Diurnally enhanced deep convection will
have the potential to be maintained well into Monday night as subtle
s/wv energy ripples eastward atop the region. Otherwise a mild night
is expected with Tuesday morning minimums around 10 deg F above the
early May climo.  Lower level warming expected on Tuesday will boost
lower elevation maximums into the middle 80s. As sfc dwpts creep
upward in the lower 60s, weak to moderate instability is fcst.
Thunderstorms have the potential to become numerous in the mountains
and perhaps gusty, within the upper diffluent flow along the
backside of the eastern seaboard subtle ridge axis.  Further warming
is slated for Wednesday with Piedmont upper 80s, again, around 10
deg F above normal.  The pattern will continue to progress toward a
more dynamic look featuring increasingly deep SW flow. Within the
increasingly sheared environment, tstms will have the potential to
produced locally damaging wind gusts.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 110 PM EDT Sunday: An eastward progressing cold front is
progged to be moving toward the Tenn Valley to start off the period
before sagging into the cwfa on Thursday.  Along and east of this
boundary, sensible wx will feature numerous showers and strong tstms
within the unstable and moderately sheared environment.  Thanks to
clouds and showers we will be stepping away from the midweek heat
although pretty solid lower 80s are expected acrs lower elevations.
As the frontal zone gets hung up as it becomes parallel to upper
flow on Friday, another piece of energy will rotate through the mean
trough, extending shower chances at least one more day.  A
considerably drier post frontal airmass should settle atop the SE
CONUS on Saturday.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Convection is still underway across the
NC Escarpment zones, but appears unlikely to affect any terminals
except KHKY this evening based on the latest round of short-range
model guidance.  Rather, it appears this activity will fizzle as
it moves east, giving way to less-active conditions overnight.
Widespread MVFR to IFR cigs are expected again tonight, and IFR
vis is expected in the mountains as well; really anywhere that
received appreciable rainfall this afternoon can expect at least
patchy fog during the predawn hours.  It will take a long time for
ceilings to lift after daybreak.  Another round of convection is
likely tomorrow, starting late morning over the SC Upstate and NC
mountains, and reaching KCLT by mid afternoon.  Retained PROB30s
from the 18z TAF issuance, with tweaked timing.  Winds generally
out of the SSW through the period, but may be variable at times
overnight.

Outlook: Enhanced moisture will combine with a weak/stalled
front through the middle of the 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. A cold front moves in for later
in the work week with continued chances of diurnal convection.

&&

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

&&

$$

SYNOPSIS...CSH
NEAR TERM...MPR/RWH
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...MPR