626
FXUS62 KGSP 101846
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
246 PM EDT Fri May 10 2024

.SYNOPSIS...
Strong storms are possible thru this evening southeast of Interstate
85. Dry high pressure will keep most areas dry through the weekend,
with mild temperatures. An unsettled pattern will take shape late
Monday, with rain chances returning and lasting through Wednesday.

&&

.NEAR TERM /THROUGH SATURDAY/...
Convection ongoing across the ern Piedmont associated with a sfc
bndry will continue active this afternoon. Soundings across the area
indicate sbCAPE values reaching arnd 1200 J/kg while latest
mesoanalysis shows 0-6 bulk shear on the order of 30-35 kts moving
in from the west. So, a few of these storms could become quite
strong to severe with large hail and damaging outflows being the
main threats. A secondary bndry will push in from the northwest this
afternoon arnd 22z and this could help maintain tstm activity into
the evening hours, altho direr llvl air will also be accompanying
this bndry, which could hinder convec development. Winds outside the
storm areas will become low-end to moderately gusty and lessen after
sunset. No great chance of fog overnight as drier air mixes into the
llvls, yet some mtn locales could see spotty dense fog. Upper
heights fall thru the day Sat as an upper wave approaches from the
northwest. This wave will bring it/s own moisture and will likely
instigate a few showers across the NC mtns during the afternoon into
the evening. Lows tonight will drop a little below normal and highs
Sat will also be held a couple degrees below normal as the new
airmass mix begins to modify warmer.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of midday Friday: Confluent upper flow between NE CONUS closed
low, and a ridge in the lower MS Valley, will allow dry sfc high
pressure to build into the CWA beginning Saturday night. This looks
to suppress diurnal convection Sunday. Mild, near-normal temps,
fairly low humidity, and light winds look to make for a nice Mother`s
Day.

Ridge will migrate east and sfc high will set up just off the East
Coast by Monday morning. Southerly flow will develop atop it within
moisture plume on warm side of occluded low moving into the Ozarks;
surface front still looks likely to be well south of the CWA. Models
vary in how quickly they develop precip; some do so Monday and others
Monday night. The setup could foster in-situ CAD once precip
develops. With increased cloud cover temps Monday should be a little
cooler than Sunday.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM Fri: Low pressure will track into the lower Ohio Valley
Tuesday, and PWATs will peak that afternoon or early evening as
southerly moisture flux comes to a head in advance of the low.  Main
shortwave trough likely will be centered over west-middle TN during
the afternoon, but some degree of DPVA could be present to further
enhance lift. How well CAD becomes entrenched may be critical, as by
the same token SBCAPE could creep into our lower Piedmont. GFS
soundings are rather skinny and not indicative of much more impact
than convectively enhanced rainfall rates. Per NAEFS and EPS member
soundings, a few hundred J/kg could overlap with around 40 kt of deep
layer shear, so a strong to severe thunderstorm is not completely out
of the question. That said, leaned slightly toward the low end of
guidance given potential CAD. Tuesday likely will be the coolest day
of the week with highs in the mid-70s, but if CAD does form highs may
stay in the 60s.

Low-level flow will turn westerly and some upslope driven precip is
possible Tue night into Wed near the TN border. The shortwave itself
will cross the CWA Wednesday morning. Temps will rebound above normal
for Wed with skies clearing and downslope winds east of the
mountains. Gradient aloft will be weaker and near-sfc winds more
veered, so less shear will be present but stronger CAPE. As such
scattered t-storms look somewhat more likely but severe threat
probably lesser. Precip chances diminish Wed night as another ridge
moves overhead behind the shortwave. Dry weather will last until the
next low approaches from the west and warm front lifts over the area.
That currently looks likely to occur Thursday night or Friday, but as
a nod to the few solutions depicting it earlier, PoPs tick upward
again Thu afternoon. Thursday temps also will be a little above
normal.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: An upper wave will cross the area this
afteroon and evening which will bring a nw/ly wind shift outside the
mtns. Some precip will be associated with this wave, but instability
looks suspect for a great thunder threat. So have included a TEMPO
-TSRA for CLT aft 22z til 00z. Otherwise, VFR conds persist and north
to northwesterly gusty winds will prevail this afternoon across most
sites and weaken overnight. No great chance of fog in the morning
with the drier air mixing in.

Outlook: VFR conditions continue this weekend. Moisture returns late
Monday with active weather possible by Tuesday.

&&

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

&&

$$

SYNOPSIS...Wimberley
NEAR TERM...SBK
SHORT TERM...Wimberley
LONG TERM...Wimberley
AVIATION...SBK