-- Discussion containing changed information from previous version are highlighted. --
159
FXUS62 KGSP 091332
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
932 AM EDT Thu May 9 2024

.SYNOPSIS...
Widespread shower and thunderstorm activity will continue through
this morning, with severe storms expected. The cold front will push
east Thursday night into early Friday morning allowing for drier
conditions. Another system approaching out of the south may bring
shower and thunderstorm chances back to the region on Friday. Drier
conditions and below normal temperatures return for the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 915 AM: Development of deep convection has become confined
to the SW CWA where modest MLCAPE still exists. Low-level shear
vectors are oriented perpendicular to this line and so a localized
threat of damaging winds and even a spin-up tor exists until the
line moves out of our area by around 10:15-10:45 AM. Tornado
Watch issued early this AM for NE GA continues, and although
the immediate threat is low, watch will be kept in place until
confidence increases that the activity now in N Alabama won`t
survive to NE GA. The remainder of our area still remains under
the stabilized atmosphere left behind by the convective activity
yesterday evening and/or overnight. Expansive stratiform rain shield
is expected to persist thru most of the morning and all corners
of the CWA should thus experience measurable rainfall by 11 AM,
with embedded anvil strikes producing occasional thunder. Still
monitoring for localized hydro issues where soils saturate from
continuing rain. HRRR has held fast to earlier trends, keeping the
stable air in place most of the day, precluding any appreciable
convective development, and showing rainfall ending from W to E
by late afternoon. Would like to see 12z cycle of guidance before
lowering PoPs below the isolated/scattered mention fcst by mid
shift for this afternoon. However, with increased confidence on
debris clouds or altostratus lingering into late day, lowered temp
trends and maxes.

Breezy winds can be expected this afternoon and early evening as a
cold front tracks across the forecast area. Cloud cover will linger
through most of the day, but should gradually clear out from west
to east late this afternoon into this evening. Lows tonight will
remain around 10 degrees above climo thanks to returning cloud
cover. Dry conditions should linger through tonight.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 317 AM EDT Thursday: We begin Friday with a wildcard,
that being whether or not there is an MCS remnant moving past to
our south which some of the guidance indicates. For what it`s
worth, the NAM is quiet and the HRRR keeps what remains to our
south. Once that is out of the way, the next item of interest is
a potent-looking short wave dropping in from the WNW late in the
day. It won`t be able to keep our temps from climbing a deg or
two above normal for highs, but this wave will bring some decent
forcing that should be able to generate some scattered shower/storm
activity at least across the mtns. The wave will drive a reinforcing
boundary through overnight. Could be some upslope shower activity,
but the chances are too low for now. The main effect will be to drop
temps about five degrees, back to below normal for Saturday. A slug
of moisture in the NW flow aloft behind the wave could result in
scattered showers over the nrn tier, especially near the TN border,
late in the day. High pressure should build in Saturday night,
with temps falling to roughly five degrees below normal.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 1252 am EDT Thursday: The rest of the upcoming weekend
looks like it should be quiet, with a mid/upper ridge axis to our
west supporting weak sfc high pressure on Sunday. Temps should
be right around normal into Monday. The ridge axis moves overhead
early Monday and then things start to go downhill. The next system
moving over the Plains on Monday will begin to spread moisture back
in from the southwest by late in the day, although the models do
not agree on when precip might develop up from the southwest. Be
that as it may, the pattern favors a quick moisture return with
sfc high pressure off the Mid-Atlantic coast, so if precip doesn`t
develop by sunset on Monday, it will overnight. The rest of the
early half of the week look busy again as the upper system slowly
approaches then moves past Tuesday night and into Wednesday. Precip
probs climb up into the Likely range, but we have removed the
categorical for the time being. Temps will stay on the cool side
on Tuesday owing to extensive cloudiness and precip. We should
get another brief break in the action in the wake of this system,
probably on Wednesday, but afterward we remain in a busy looking
part of the flow with perhaps another upper feature moving in by
the end of the period. Temps could pop back up about five degrees
above normal on Thursday, but there is much uncertainty.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Another round of strong storms is pushing
into the western Carolinas this morning leading to widespread SHRA
and TSRA. This activity is leading to mainly LIFR to MVFR
restrictions across portions of the terminals. Went with TEMPOs
across all the TAF sites from 12Z-16Z for TSRA with prevailing VCSH
or SHRA. Strong, gusty winds can be expected within stronger
thunderstorms. Should see drier conditions develop late this morning
into early this afternoon, allowing restrictions to lift, with VFR
expected by 17-19Z. Wind direction will generally be variable
through daybreak with shower and thunderstorm activity around, but
should eventually pick up out of the SW shortly after sunrise. Winds
will remain SW through this afternoon before turning WNW across the
mtns and WSW east of the mtns this evening into tonight. Low-end
gusts are expected to develop this afternoon as a cold front track
over the western Carolinas. Dry conditions should linger through
tonight. Patchy fog may develop across portions of the terminals
overnight, but confidence on this is low with this being towards the
end of the TAF period.

Outlook: A system lifting out of the south my increase shower
and thunderstorm chances again on Friday, but confidence on this
remains low. Drier conditions can be expected this weekend.

&&

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

&&

$$

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