Severe Thunderstorm Warning 138, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
539 PM EDT Sun Jun 9 2024

.SYNOPSIS...
A cold front moves south of our area becoming stationary through
mid week with dry conditions under weak high pressure for Monday
through Thursday.  Isolated to widely scattered showers and
thunderstorms are expected by next weekend as a weak cold front
approaches from the north.  Temperatures are expected to be well
above normal at end of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
Key Messages...

1) Strong to severe storms possible this evening.

2) Another round of sct to numerous showers is likely overnight and
into early Monday morning, largely confined to the I-85 Corridor and
south of it.

3) Dry conditions return Monday afternoon.

As of 5:25 PM EDT Sunday: A fairly robust cluster of showers with
some embedded thunderstorms associated with a weak cold front is
currently approaching the NC/TN border. The latest CAM guidance has
this activity moving into the NC mtns over the next couple of hrs
and continuing its SE trajectory and eventually moving SE of our
CWA later tonight. 1000 to 1500 J/kg of Sfc-based CAPE has already
developed across much of our area and 30 to 40 kts of deep-layer
shear is also in place. This should allow isolated strong to severe
thunderstorms to develop as this activity moves thru our area this
evening. The SPC Day 1 Severe Wx Outlook has the majority of our
fcst area in a Marginal Risk and this still seems reasonable. The
main hazards with any severe storms that develop are damaging wind
gusts and large hail. The most likely window for severe wx appears
to be slightly later, ie, from roughly 6pm to 10pm EDT.

Otherwise, a brief drying period is expected once the cold front
pushes south and east of the fcst area later this evening. Upper
shortwaves will track overhead the forecast area overnight into
early Monday morning allowing for widespread cloud cover and rain
showers to develop. Instability will be lacking so maintained no
mention of thunder overnight. Lows tonight will end up a few degrees
above climatology thanks to both cloud cover and precip limiting
radiational cooling. Timing of the second wave of convection will
be from roughly 3am-9am. However, some isolated activity may linger
across the southern zones throughout the morning hours. Dry high
pressure will gradually build in from the west throughout Monday
allowing dry conditions to return by Monday afternoon. Temperatures
will be cooler on Monday, around 2-4 degrees below climo, with highs
only reaching the low 80s east of the mtns.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 205 PM EDT Sunday: Short waves drop across the area through
an upper trough on Tuesday. The trough moves east Wednesday with
weakening NW flow over our area. The cold front from the near term
slowly moves south away from the area Tuesday with dry high pressure
building in on Wednesday. Can't rule out an isolated shower Monday
evening with lingering low level moisture and weak forcing, but
chance too low to include in the forecast for now. It will be breezy
Monday night and Tuesday though. Dry conditions and light winds
expected Wednesday. Below normal lows Monday night rise to near
normal Tuesday night. Near normal highs Tuesday rise a couple of
degrees above normal Wednesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 220 PM EDT Sunday: Still some run to run consistency issues
with the guidance. That said, there does seem to be a trend toward a
drier forecast. A series of weak short waves move through the flow,
mainly north of our area through Friday. Then a semblance of a Rex
Block develops Saturday into Sunday with an upper anti-cyclone
sliding into the Southeast by Sunday, and a weak upper low moving
east across the Gulf of Mexico. The result is weak and generally dry
high pressure Wednesday and Thursday with the potential for diurnal
convection Saturday as a weak cold front crosses the area. Diurnal
convection possible again Sunday as a moist southerly flow develops.
A warming trend takes place with highs nearly 10 degrees above
normal by Saturday, which drop back a few degrees for Sunday. Lows
rise to around 10 degrees above normal.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
Key Messages...

1) Thunderstorms Expected this Afternoon Ahead of a Cold Front

2) Widespread Rain expected Overnight into early Monday Morning

3) Cigs and Vsbys should generally range from MVFR to VFR through
the period

At KCLT and elsewhere: Light rain continues pushing east this
afternoon, with only isolated activity lingering along/near I-77.
Low-end gusts are noted at KAVL and KAND as of 18Z and KGSP and KGMU
could see gusts develop this afternoon as well. Gusts should
diminish by the early evening hours. Cloud cover is starting to
clear across portions of the terminals this afternoon which should
allow the atmosphere to become unstable. However, cloud cover will
gradually increase from west to east again, becoming BKN to OVC,
later this afternoon ahead of a cold front. The cold front will lead
to -SHRA/-TSRA late this afternoon into early this evening as it
tracks overhead. Have TEMPOs at all terminals, with the exception of
KAND which is expected to remain dry, to account for the convective
potential. Cigs should generally remain VFR outside of TSRA. Wind
direction remains W'ly east of the mtns this afternoon. Winds will
remain NW at KAVL through the TAF period, while winds east of the
mtns will turn N/NW behind the front this evening into tonight.
Brief drying is expected before a round of widespread showers tracks
across the terminals overnight into early Monday morning. Handled
this potential with PROB30s across all terminals. -SHRA should start
between 07Z and 09Z and push out between ~11Z and 13Z and should
allow cigs to fall to high-end MVFR levels, mainly across the SC
Upstate terminals. High pressure will build into the region
throughout Monday leading to much drier conditions and allowing VFR
cigs to gradually return. Cloud cover will gradually decrease
throughout Monday becoming FEW to SCT. Winds east of the mtns should
become more variable around daybreak Monday before turning WSW/SW
Monday afternoon.

Outlook: Dry sfc high pressure will linger through mid-week leading
to quieter weather.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
539 AM EDT Sun Jun 9 2024

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ008>014-019-101>109-100945-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Alexander-
Iredell-Davie-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Catawba-
Rowan-Graham-Northern Jackson-Macon-Southern Jackson-Transylvania-
Henderson-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union NC-
Caldwell Mountains-Greater Caldwell-Burke Mountains-Greater Burke-
McDowell Mountains-Eastern McDowell-Rutherford Mountains-
Greater Rutherford-Polk Mountains-Eastern Polk-Cherokee-York-
Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
Oconee Mountains-Pickens Mountains-Greenville Mountains-
Greater Oconee-Greater Pickens-Central Greenville-
Southern Greenville-Northern Spartanburg-Southern Spartanburg-
539 AM EDT Sun Jun 9 2024

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

Scattered showers and thunderstorms are expected this afternoon and
evening. One or two may become strong to severe. Primary threats will
be damaging wind gusts, large hail, and cloud-to-ground lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

CAC