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757
FXUS62 KGSP 062134
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
534 PM EDT Mon May 6 2024

.SYNOPSIS...
A summerlike weather pattern remains through mid week with mainly
afternoon and early evening showers and thunderstorms. Temperatures
will be well above normal Tuesday through Thursday. Showers and
thunderstorms will be more numerous ahead of a strong cold front
which will cross our region Thursday night and Friday.  Expect drier
and cooler weather for the weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
As of 531 PM EDT Monday: Scattered showers and thunder west of I-26
have come to a focus across the northwestern Upstate along an axis
of better deep shear and 2500+ J/kg sbCAPE extending across and
east of the Savannah River Valley.  This activity has prompted a few
severe warnings, mainly for large hail, which stands to reason given
the icy cores but not-so-impressive DCAPE values across the area.
Nonetheless, for cells developing on the southern flank of this
activity, the environment will feature higher DCAPE and thus
support somewhat more of a wind threat as compared to the cells
presently in the corridor from Greenville to Pickens.

Otherwise...as flow turns NW aloft this evening, CAM guidance
continues to depict additional waves of scatter showers and
thunderstorms through late evening...which should then fizzle
as instability wanes.  The latest couple runs of the HRRR now
bring a semi-organized line of cells across the mountains, with
some redevelopment over the western SC Upstate after midnight.
If that happens...instability will be minimal but nonzero, and
shear will remain elevated...such that a stray strong to severe
storm couldn`t be ruled out.  Low temps early tomorrow will be
roughly 10 degrees above climatology again.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 215 PM EDT Monday: A flat upper ridge will be in place across
the area Wednesday with weak short waves rippling through the flow
and across the area. A stronger short wave crosses the area early
Thursday as an upper low moves into the Great Lakes. At the surface,
a weak east/west oriented front stalls over the area Wednesday, with
a cold front moving in from the west on Thursday. The air mass
becomes very unstable Wednesday with moderate shear and mid level
dry air leading to increased DCAPE and sfc delta Theta-E values.
Coverage will be higher across the mountains, but severe storms will
be possible at any location across the area given these parameters.
Moisture increases on Thursday with less mid level dry air, DCAPE,
and sfc delta Theta-E values. Instability also falls, but could
remain in the moderate range while shear increases, approaching
strong territory. Convective coverage still favors the mountains,
but at least likely PoP will be featured across the area. Severe
storms will again be possible, but overall chance is more uncertain.
Highs Wednesday will push 90 degrees outside of the mountains, and
mid to upper 80s in the valleys then fall a few degrees Thursday.
Lows will be well above normal as well.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 240 PM EDT Monday: The Great Lakes low opens into a trough
which moves into the area Friday. A series of short waves keeps the
general troughiness over the eastern CONUS through the end of the
period. With the trough moving in on Friday, cyclogenesis takes
place near the Carolina coast along the cold front that moves
through on Thursday. Guidance keeps going back and forth on the
location of the front and cyclogenesis, along with any lingering
moisture and resulting precip. Have continued the trend of chance
PoP for now given the uncertainty. A series of weak clipper-like low
pressure centers of frontal systems move near or over the area
through the rest of the period. This leads to isolated to possibly
low end scattered showers for the mountains each day with dry
conditions elsewhere. Temps fall to a few degrees below normal by
Saturday, then rise back to near normal through the end of the
period.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Another challenging fcst all-around for
the terminals. Still expect mostly VFR conditions this afternoon
and evening (outside of any showers and/or thunderstorms). We`ve
seen a lull in shower activity since late this morning, however
another round of sct convection is expected to move thru our area
later this aftn and into the evening. This is mostly handled with
VCSH and TEMPOs for TSRA at KCLT, KHKY, and KAVL. Per the latest
CAM runs, the convective coverage looks more sparse for the Upstate
terminals, so I just have VCSH with PROB30s for TSRA. Activity could
linger well into the overnight and early morning across our area,
but thinking it will be mostly showers after about 06z overnight
and most likely impact KAVL. Visby and cig restrictions return to
the area just before daybreak on Tuesday, with predominately MVFR
visby and IFR cigs expected at most sites. Expect visby to improve
and cigs to sct out by roughly 14z tomorrow with VFR for the rest
of the taf period.

Outlook: Moist profiles will combine with a weak/stalled front thru
the mid-week, resulting in a period of active, mainly diurnal convec-
tive weather each day. There is potential for restrictions associated
with widespread fog and/or low clouds each morning. A cold front moves
in later in the week with continued chances of diurnal convection.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...JPT/MPR
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JPT