792
FXUS62 KGSP 300610
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
210 AM EDT Sun Jun 30 2024

.SYNOPSIS...
Warming temperatures as shower and thunderstorm chances increase
ahead of a robust cold front arriving Sunday. Drier and cooler
conditions return Monday and Tuesday behind the front, before summer
heat returns on Wednesday and beyond.

&&

.NEAR TERM /THROUGH TODAY/...
As of 200 AM Sunday...Seeing the requisite shower activity once
again early this morning in the continued light southerly moist
upslope flow across the region. Like last night, this should
continue on toward daybreak with scattered coverage mainly close
to the higher terrain. Cloud cover will help to keep temps above
normal and dewpoints relatively high even for this time of year.

Otherwise...a cold front will be just to our NW on Sunday, helping
trigger convection across eastern TN and in the NC mountains. There
will also be a pronounced lee trough setting up across the Piedmont,
providing convergence for convection. Guidance is in good agreement
the approaching upper trough and the aforementioned front and
trough should support decent coverage of showers and tstms across
the area. SBCAPE will range from 1500-2500 J/kg and 0-6 km bulk
shear around 20-25 kt will be enough for quasi-organized clusters of
storms drifting toward the east. A few storms may produce damaging
wind gusts, and the Day 2 SPC outlook of marginal severe for our
area looks good. Convection will likely get going late enough to
allow peak heating to get temps into the mid 90s, while dewpts
remain in the mid 70s across much of the Piedmont Sunday aftn. This
results in heat indices getting into the 100-107 range across the
I-85 corridor and southeast. Have issued a Heat Advisory for the
NE GA Piedmont, the Upstate, and SW NC Piedmont for Sunday aftn
into early evening.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
As of 150 PM Saturday: By Sunday night, what is left of a frontal
boundary clears the CWA and dissipates to the south. Synoptically,
high pressure builds in from the west with an amplifying high over
the southern CONUS. To the north, a trough attempts to dive
southward and turns flow aloft form the NW. High pressure at the sfc
will also keep sfc winds out of the N/NW, maintaining a stream of
drier and somewhat cooler air for the short term. Modeled upper air
guidance shows a stout subsidence aloft with a mid-level inversion
at the top of the BL, snuffing out rain chances Monday afternoon and
into Tuesday. A break in the heat will occur Monday and into
Tuesday, before a snap back to summertime reality. As far as fire
concerns with drier air during this time, it will drop RH values
into the 40 percent range, but critical thresholds are not
anticipated. Winds could have some low-end gusts Monday afternoon.
Fuel moisture is dry, especially east of the mountains meaning
vegetation is more prone to ignition. Otherwise, temperatures look
to be a few degrees below climo until the next period.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 200 PM Saturday: The summertime pattern continues into the
extended. Tuesday night and into Wednesday, the trough off to the
north starts to deamplify as the ridge axis slides over the eastern
CONUS. A strong area of high pressure also grows over the southeast
and Mid-Atlantic regions. As the heights rise, so do the
temperatures. Guidance from the GFS and EURO depicts moisture
returning toward the end of the week as sfc flow remains light and
starts to veer more E/SE. The slow advection of moisture from
previous model runs, does keep dewpoints more reasonable and in the
low 70s by end of week. This will have a direct impact on heat
indices, especially those locations east of the mountains. 90s
should return by Thursday and beyond. Once the high pressure starts
to weaken on Thursday and Friday, a return to more diurnally driven
convection is possible across the mountains, though confidence is
low. All in all, the extended looks relatively dry, temps ramp up
through next weekend, and qpf response is minimal.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: For the third night in a row we are seeing
widely scattered showers developing in a light moist southerly
flow across the region. Will be handling the restrictions
with amendments, as confidence in showers impacting any of the
terminals is sketchy through daybreak. Wind will be light S or
calm. On Sunday, expect with minimal heating we should develop
a low cloud deck, followed by the development of deep convection
in the early afternoon. The CAMs show some decent agreement, so
confidence is high enough to present a TEMPO for the mid/late
afternoon hours at most terminals. Convection should persist
well into the evening ahead of an approaching cold front, so a
PROB30 will be employed. Restrictions should be contained to the
TEMPO/PROB30 groups. Wind should be light S to SW. The cold front
should move southeast across the region in the late night hours
with wind coming around to NW after the front moves through.

Outlook: The cold front will push thru and stall just south of
the area, resulting in quieter weather for Monday thru mid-week.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from noon today to 8 PM EDT this evening for
     GAZ018-026-028-029.
NC...Heat Advisory from noon today to 8 PM EDT this evening for
     NCZ070>072-082.
SC...Heat Advisory from noon today to 8 PM EDT this evening for
     SCZ008>014-019-104>109.

&&

$$

SYNOPSIS...CP
NEAR TERM...ARK/PM/SBK
SHORT TERM...CP
LONG TERM...CP
AVIATION...PM