181
FXUS62 KGSP 191759
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
159 PM EDT Fri Jul 19 2024

.SYNOPSIS...
A nearly stationary front will meander across our region through
early next week providing a focus for above normal chances of mainly
afternoon and evening showers and thunderstorms. Another cold front
will approach from the north later next week. Temperatures will be
near normal or just a bit cooler than normal.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 10:05 AM Friday: We`ve seem some breaks in the cloud cover
over the past couple of hrs as daytime heating ramps up, yet a
number of sites are still reporting low cigs below 1000 ft. These
should sct out as we approach noon, however sct to bkn higher
clouds will likely persist for the rest of the day.

Otherwise, a broad upper trof will remain over the eastern CONUS
thru the period with a short wave moving into the area in the SW
flow. A weak low pressure center moves along the stalled frontal
boundary across the area. With copious deep moisture over the area,
this will create enough forcing for widespread showers this aftn
and evening, with showers lingering overnight. There will be enough
instability for thunderstorms, but overall instability will be on
the lower side with clouds keeping a lid on strong heating. The lack
of dCAPE and effective shear will keep severe chances on the low
side. Given the amount of moisture and convective coverage, isolated
heavy rain and localized flooding will be possible. Morning clouds
will also help delay convective initiation until mid to late aftn,
with convection continuing into the evening. Coverage tapers off
overnight but likely lingers through the night. Highs should end
up as much as 5 degrees below normal, with lows near to slightly
above normal.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 207 AM Friday...The synoptic pattern will remain
largely stagnant heading into the weekend with a stout upper ridge
over the Four Corners region slowly retrograding into the Great
Basin. Associated tall ridging will extend as far north as British
Columbia and Alberta where temperatures will make a run at 40 C.
Downstream troughing is progged to extend from the Great Plains into
the Appalachians with another upper ridge centered over the
Atlantic. This synoptic pattern will keep the Southern Appalachians
within a broad convergent southwest flow regime. A deep plume of
1.75-2.25" PWATs entrenched across the area combined with the
influence of a nearby stalled frontal boundary just west of the
mountains will support above average chances for afternoon and early
evening showers and thunderstorms both Saturday and Sunday. As with
any summer convection, moderate instability could support several
instances of severe pulse storms with water loaded microbursts being
the primary threat. In addition, repeated rounds of rainfall could
lead to isolated flash flooding, especially where any storms are
able to train and/or become focused by mesoscale influences.
Increased clouds and coverage of showers and storms will also keep
temperatures in check with highs a couple degrees below average and
mild overnight lows.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 224 AM Friday...An active pattern will continue well into the
extended forecast with little change to the position of synoptic
features. Upper ridging will meander across the Great Basin/Four
Corners while downstream troughing continues to reload as periodic
shortwave perturbations dive through the Great Plains. Thus, a deep
moisture plume will be maintained across the area within persistent
southwest flow. Above normal chances for showers and thunderstorms
will continue through next week along with below average
temperatures. Repeated rounds of convection may eventually heighten
a threat for flash flooding, but this will be predominately driven
on the mesoscale and near impossible to pin down at this time range.
Some members of guidance depict a period of increase flow through
the column around mid week, which if realized could provide a boost
in moisture transport and a possible focus for flash flooding.
Otherwise, at least isolated pulse severe storms cannot be ruled out
any given day with wet microbursts being the primary hazard.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Expect another round of sct to numerous
showers and thunderstorms and associated restrictions this aftn/
evening across the fcst area. This was handled with VCSH and
TEMPOs for TSRA going thru roughly 23 to 24z. SHRA may linger
overnight with at least MVFR cigs becoming IFR overnight with
a decent chance for MVFR visby as well. Expect the lower cigs
to linger thru late morning at most sites with VFR returning
for the last few hours of the period. Winds will remain light
thru the period and eventually favor a SWLY direction by the
end of the period early tomorrow afternoon.

Outlook: Expect sct to numerous showers and thunderstorms each
afternoon/evening into early next week. Morning fog/low stratus
will be possible each day, especially in the mtn valleys and over
areas that received rainfall from the previous day.

&&

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

&&

$$

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