213
FXUS62 KGSP 090806
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
406 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/...
As of 400 AM EDT Thursday: The Tornado Watch for northeast Georgia
and the SC Upstate was allowed to expire at 4 AM. The line of strong
to severe storms have mostly pushed south and east of the forecast
area, but an isolated strong to severe storm may continue grazing
far southern NE GA and the far southern SC Upstate the next hour or
so. What`s left behind the main line is stratiform rain with
embedded thunder at times. The severe threat will be lower through
the rest of the morning due to the atmosphere being worked over from
earlier activity. However, CAMs depict another line of convection
making a run for the forecast area around between roughly 6am-8am.
The SPC mesoanalysis page shows SBCAPE values climbing back to 500-
1500 J/kg across the forecast area by 9am. With deep layer shear
expected to increase to 40-50 kts by mid to late morning ahead of an
approaching cold front, the strong to severe storm potential may
return later this morning, but confidence on this remains low and
will be highly dependent on how much the atmosphere can recover
before the next batch of convection. The flooding threat will
gradually ramp up through the morning hours as rainfall totals pile
up. However, with only a one Flood Advisory currently in place, a
Flood Watch looks unlikely at this point as mainly nuisance flooding
in low-lying/poor drainage areas is expected.

With activity expected to linger through the late morning hours,
have likely to categorical PoPs area-wide through this morning. With
activity expected to gradually come to an end from west to east this
afternoon, capped PoPs to chance through the afternoon hours. Highs
this afternoon will be a few degrees cooler than yesterday, and
around 3-6 degrees above climo. 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.

&&

.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 /08Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Widespread SHRA and TSRA are tracking over
the terminals this morning leading to mainly LIFR to MVFR
restrictions. With the strongest activity expected to continue
through the next few hours, went with TEMPOs for TSRA from 06Z-10Z
for all terminals. Strong, gusty winds can be expected within
stronger thunderstorms. From 10Z-15Z have SHRA with a PROB30 for
TSRA as thunder should become more isolated once the main line of
activity pushes east. Should see drier conditions develop by the
late morning to early afternoon, which should allow restrictions to
lift across the terminals. Wind direction will generally be variable
through daybreak with shower and thunderstorm activity around, but
should eventually pick up out of the SW around 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.

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
SHORT TERM...PM
LONG TERM...PM
AVIATION...AR