396
FXUS62 KGSP 240610
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
210 AM EDT Mon Jun 24 2024

.SYNOPSIS...
A cold front will cross the area early this morning leading to
scattered showers and isolated thunderstorms, mainly across the
mountains. Drier and less humid conditions return behind the front
this afternoon into Tuesday. Humidity returns again on Wednesday and
lingers through the weekend. Another cold front will track across
the area Wednesday night into Thursday bringing better shower and
thunderstorm chances. Showers and thunderstorm chances may Friday
into the weekend.

&&

.NEAR TERM /THROUGH TODAY/...
As of 150 AM: Patch of showers with a few embedded lightning strikes
is moving over the SW NC mountains attm, driven by weak cold
front. This activity will run into more stable air as it pushes
into the foothills, although in short term progs, some moisture
pooling is evident near the front, and at least slight MUCAPE looks
to linger until drying occurs aloft behind the front. Downslope
flow will also be a limiting factor, and thus it is not much of a
surprise that CAMs depict the current activity fizzling before it
reaches the I-85 corridor. Did keep a slight-chance shower/t-storm
mention northwest thereof, particularly in NE GA and the western
Upstate where some showers might "sneak around" the mountains. These
chances advect southeast and gradually diminish with time such
that precip should be pretty much over for the lower elevations by
sunrise. Some low cloud cover and spotty showers are seen over the
Cumberland Plateau/Mountains, and with upslope moisture remaining,
saw fit to keep small PoPs until 8-9 AM along the TN border.

In reality, this isn`t so much a cold front as it is more of a dry
front, which is typical for this area at this time of year. Behind
the boundary, a sfc high will build in thru afternoon from the NW on
the strength of an upstream ridge. The upshot is that temps today
might ultimately be similar to Sunday afternoon, but the RH should
be noticeably less (and less than we expected a few days ago),
such that apparent temps should stay well below the Heat Index
criteria. Precip chances will also be limited to a slight chance
over the eastern-most zones in the middle part of the day before
the boundary moves off toward the Coastal Plain in the afternoon.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
As of 1230 PM Sunday...Upper heights will begin to rise early Tue
which will support a Canadian sfc high to the north. This high will
dominate the weather into Wed as it becomes reinforced and ridges
down the east coast. Relatively dry and cool air will mix in, but
still expect deep subs to allow for temps in the l90s east of the
mtns and u80s across the mtn valleys. Soundings show mixing into the
drier air aloft which will help keep sfc dwpts in the u50s to l60s
and HI values below adv criteria. The atmos becomes more dynamic
early Wed as a pos tilted h5 s/w pushes in from the west. This wave
will likely produce sct showers and a few general to strong tstms
across the NC mtns with isol activity east thru the day. Rainfall
amts will be modest and wont make much of a dent in the below normal
precip amounts received this month. Surface dewps will bump up in
this environ ahead of the front and along with temps reaching the
mid to upper 90s east of the mtns, heat index values could rise into
advisory levels across the Lakelands. Overnight temps will remain
rather warm with mins held abt 5-7 degrees abv normal.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 205 PM Sunday...An upper trof axis continues to cross the area
Wed night which will likely maintain chance thunder across the NC
mtns and isolated storms east. With high pressure pushing a llvl
convg zone into the area during the afternoon, expect another round
of tstms across the NC mtns. Meanwhile, heights will rise as a
subTrop ridge builds in from the west. This neg forcing will help
keep tstm strength in the general category Thu afternoon and again
Fri afternoon when the llvl flow brings in an upslope e/ly se/ly
flow. The building ridge dominates the pattern into the weekend and
makes for a summertime pattern with PoPs a little below climo and
temps remaining above normal. Expect highs in the m90s each
afternoon and lows likely held a couple cats abv normal. Heat
indices look to remain below adv level Thu and Fri, yet may reach
criteria Sat as dewpts surge ahead of a sfc front approaching from
the northwest Sat night.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Weak sfc front to cross the terminal area
early this morning. This will bring an area of SHRA near KAVL
and potentially KGSP/KGMU/KAND before dawn. An isolated TSRA is
additionally possible, but confidence only high enough to mention
this at KAVL. Lower VFR clouds will develop as the front passes the
terminals, with a small chance of MVFR at KAVL as well. Winds will
shift to NW after the fropa, but not expected to occur at KCLT until
diurnal mixing begins around 13z. A very small chance of diurnal
convection exists well south of KCLT and the SC sites today, but
otherwise post-frontal drying and subsidence is expected to result
in just cumulus. Development of easterly flow tonight could lead
to some low VFR stratocu near KCLT/KHKY but of low impact. Brief
mountain valley fog not out of the question at KAVL after 06z Tue.

Outlook: Dry weather and suppressed convection again Tuesday. Widely
scattered SHRA/TSRA may return as soon as Wed aftn/evening, with
seasonable summertime weather returning then and continuing into
the weekend.

&&

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

&&

$$

SYNOPSIS...AR
NEAR TERM...PM/Wimberley
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...Wimberley