102
FXUS62 KGSP 131737
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
137 PM EDT Thu Jun 13 2024

.SYNOPSIS...
Dry conditions will continue into the weekend as a hot upper level
ridge builds into our region from the west.  There may be a brief
afternoon ridgetop shower or storm in the mountains.  Isolated to
widely scattered showers and thunderstorms are expected early next
week as a weak cold front approaches from the north.  The hottest
days are expected to be Friday and Saturday, then the heat will
continue into next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Noon Update...No changes made to the going fcst. Temps still on
track to reach arnd 90F outside the mtns and m80s across the mtn
valleys. Surface humidity will continue to drop thru the afternoon
with values approaching 35-40 percent...so a nice feeling warm day
in store.

Upper-level shortwave currently situated over the Southeast via mid-
level WV imagery will shift offshore during the daytime period,
while interacting with a disturbance that is highlighted by NHC. No
impacts are expected as the associated cirrus should gradually clear
from west to east through the morning and afternoon hours, leading
to maximized insolation at the surface during peak heating. With
warm air aloft still in place and influence from a weak surface
ridge, expect temperatures to rise well into the 80s, with a few
lower 90s in locations south and east of the I-85 corridor. Despite
a mid-level subsidence inversion in place, providing a hostile
environment for convective initiation, CAMs continue to support the
idea of enough mechanical lift to overcome the cap to produce
ridgetop showers and thunderstorms during peak heating. Kept
mentionable PoPs for this development, but very weak shear
parameters would suggest that these storms won`t budge much and
should have a hard time moving anywhere outside of the mountains.
Modest mixing within the boundary layer should place dewpoints in
the upper 50s to lower 60s to help keep heat indices at bay. Placed
between the exiting shortwave and an encroaching cold front from the
northeast Thursday night will keep the sensible weather quiet, with
some mix of cloudiness across the CFWA. Overnight lows are
forecasted to be near-normal as a result.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Key Messages:

1) Isolated Diurnal Shower and Thunderstorms Possible Saturday

2) Better Chance for Diurnal Showers and Thunderstorms on Sunday

3) Hot Temperatures Stick Around in the Mountain Valleys and East of
the Mountains Each Afternoon

As of 130 PM EDT Thursday: An upper anticyclone will gradually build
into the Southeast through the short term. Meanwhile at the sfc, a
dry and weak cold front will track across the forecast area Friday
evening into daybreak Saturday. No precipitation or increase in
cloud cover is really expected with such dry air in place aloft. The
southern periphery of a sfc high pushing east across the eastern
Great Lakes region will graze the forecast area on Saturday keeping
mostly dry conditions around. A few isolated showers and
thunderstorms will be possible across the southwest NC mountains
Saturday afternoon. Capped PoPs to slight chance (15%-17%) for now.
The center of high pressure pushes off the Northeast Coast Sunday
afternoon but the southwestern periphery of the sfc high will
continue to extend into the forecast area through the rest of the
short term. This will allow SE`ly winds to develop, leading to
return flow off the Atlantic. With this influx of Atlantic moisture
expected, diurnal shower and thunderstorm chances will increase on
Sunday. Have chance PoPs across the western zones (15%-35%), with
the highest PoPs confined to the mountain zones. Temps will be
around 4-6 degrees above climo through the period, with highs
rebounding into the upper 80s/lower 90s in the mountain valleys and
east of the mountains.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 320 am EDT Thursday: An upper anticyclone is forecast to
steadily lift into the Northeast early in the new work week,
establishing a deep/weak easterly flow across our forecast area.
This will result in increased moisture and improved chances for
diurnal convection throughout the extended. However, "improved" is a
relative term, as current global model guidance suggests that
diurnal convection will merely by typical for this time of year,
with widely scattered (30-40 PoPs) activity expected across the
mountains, and isolated showers and storms forecast across the
remainder of the area. Otherwise, temperatures will moderate,
although still likely remaining a little above normal through the
period.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Expect VFR conds to continue thru the 18Z TAF
set. Strong riding aloft will continue make for mainly dry conds
across the area expect for mtn top convec away from KAVL. A weak sfc
bndry pushes east during the afternoon and there could be a few
showers approaching KCLT late, but it looks to occur later than 00z
Sat. Winds will remain quite weak and ill defined at times, but
generally se/ly today then becoming aligned more w/ly to nw/ly Fri
afternoon with bndry passage.

Outlook: Surface high pressure remains over the area through the end
of the week with minimal chance for convection and associated flight
restrictions.

&&

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

&&

$$

SYNOPSIS...JDL
NEAR TERM...CAC/SBK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...SBK