946
FXUS62 KGSP 192337
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
737 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/...
As of 545 PM: Scattered showers continue near the Blue Ridge
Escarpment, generally weakening as evening cooling occurs, but with
cumulus still looking vertically developed in spots particularly
west of Hendersonville. Weak northerly steering flow will persist
this evening and there is enough instability in the foothills to
expect some isolated development south to I-85 in the Upstate
and perhaps another county or so south of the current activity
northeast of Asheville. Won`t rule out new development until 02-03z
in our northern NC zones with weak axis of vorticity evident on
water vapor imagery. Rainfall rates are expected to be too small
to incur any hydro threat; lightning is proving quite isolated.

Revised overnight temp and sky trends but lows would appear on
track from prev fcst. Overnight temps still look to 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 THURSDAY/...
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 /00Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: A few -SHRA will persist near the Blue Ridge
Escarpment in the first couple hours of the period, warranting
VCSH at KAVL. Otherwise remaining cu will dissipate leaving just
FEW-SCT mid cloud for most of the night, with winds remaining
light. Although mixing was better today dewpoints remained at
summerlike mid 60s to near 70; coupled with a slight easterly
flow above the sfc, radiation fog/stratus appear likely in the
mtn valleys and also near rivers in the Piedmont. Hence a period
of IFR is included at KCLT/KAVL/KHKY in the morning; with lesser
support from guidance and drier soils have gone no worse than
MVFR at KGSP/KGMU, although trends will need to be monitored
overnight. Winds pick up from the N to NE during the morning but
should remain less than 6 kt. At KCLT slow improvement is expected
with VFR not returning until midday. Isolated SHRA/TSRA possible
in the mountains but chance too low to mention at KAVL. Winds could
veer to near due E if not ESE late in the day but with speeds light
and impact low, did not introduce another group to reflect shift.

Outlook: No appreciable return of moisture or precip chances
expected until early to middle of next week. Daybreak restrictions
could recur each morning especially in mountain valleys.

&&

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

&&

$$

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