053
FXUS62 KGSP 191820
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
220 PM EDT Thu Sep 19 2024

.SYNOPSIS...
The limited coverage of any showers and storms on Friday afternoon
will be confined to the mountains.  Meanwhile, high pressure begins
to build into the region from the north and west giving our region a
dry weekend. Temperatures will be above normal through the weekend
then closer to normal through the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
Isolated showers are developing across the NC mtn ridges currently
and expect activity to persist into the evening hours. These cells
have been very short-lived, barely a scan or two, as dry n/ly air
abv h85 is pushing in. Soundings show cooling h5 temps this afternoon
and LFCs easily reached, however, sbCAPE will remain generally
under 500 J/kg. This will be enuf instability to produce a few
general thunderstorms capable of producing high rainfall rates as
PWAT values remain abv 1.2 inches. A hydro threat is not great tho
as a modest steering flow will continue moving storms along.

Overnight temps will drop into the u50s across the mtns and
crossover temps will likely be reached or exceeded possibly leading
to the formation of dense fog across the mtn valleys and east within
the adjacent foothill lowlands. A drier day is on tap for Fri with
less cloud cover as deep subsidence increases from the west and hipres
dominates at the sfc. There may be some limited convective activity
across the mtns due to ridge top convg, but coverage of precip will
be low-end due to the aforementioned subs and mlvl warming. Highs
Fri will likely reach a couple cats abv normal across the forecast
area.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 145 PM EDT Thursday: Upper ridge will be dominating the
Southern Plains as we move into the short term, with trough in place
over the East Coast. With heights rising through the period,
increasing subsidence will generally keep pops out of the forecast,
but a weak shortwave moving down the northerly flow aloft may bring
just a bit of moisture to the area briefly Saturday night, so cannot
rule out some showery activity in the NW NC Piedmont. Bigger story
will be the temperatures increasing through the period, with
temperatures trending upwards both Saturday and Sunday,
uncomfortably unseasonably warm with highs approaching mid 90s in
the Upper Savannah by Sunday afternoon as the upper ridge axis
pushes closer to us and the upper trough begins to lift out.
Elevated dewpoints underneath the increased ridging aloft will keep
overnight lows a couple of degrees above normal as well.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
As of 200 PM EDT Thursday: The upper ridge will continue to push
east as we move into the extended, eventually flattening and
shifting slightly south as a mid-level low works its way out of the
Rockies and across the Northern Plains. A stronger system passing
across southern Canada will drag a cold front across the Great Lakes
on Sunday, approaching the OH Valley late in the weekend and
eventually toward the Southern Appalachians as we begin the new work
week, bringing a return of pops to the mountains. Timing this far
out is uncertain, and the first round of precip may dry up before
the secondary round associate with the Northern Plains wave moves in
Tue-Wed. High temperatures will be knocked back down closer to
seasonal normals with the increasing clouds and precipitation,
though increasing moisture will keep overnight lows above normal.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: VFR conds will continue across all sites this
evening, except at KCLT where BKN MVFR may persist off and on over
the next couple hours. Scattered showers and a couple thunderstorms
will develop across the mtns, but confidence is too low for a
precip/vsby mention at KAVL and KHKY. Good rad cooling overnight
will help develop fog, possibly VLIFR, at KAVL and KHKY, while MVFR
restrictions due to VSBY and CIGs is possible at KCLT arnd and thru
daybreak. VFR conds return all sites aft 14z and continue thru the
period. Winds remain aligned generally ne/ly and low-end.

Outlook: No appreciable return of moisture or precip chances
expected until early to middle of next week.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...SBK
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...SBK