Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1046 PM EDT Sat Mar 27 2021

.SYNOPSIS...
A strong cold front will cross Tennessee tonight then cross
our area around midday to early afternoon Sunday.  This front will
be preceded by another round of thunderstorms.  Behind the front,
temperatures will return to normal as high pressure builds in for
Monday.  More unsettled weather looks to be in store for the region
by the middle of the week as another strong cold front reaches our
region from the northwest.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 1030 pm: Isolated to widely scattered convection continues to
fire in the vicinity of an outflow boundary across the Lakelands and
upper Savannah River Valley region. However, the combination of
relatively stable outflow air and nocturnal cooling has shoved much
of the appreciable surface-based instability southwest of the
forecast area, and convection has therefore become increasingly
benign, with even lightning becoming increasingly difficult to come
by. Meanwhile, scattered to numerous convective coverage continues
across middle and east Tennessee, but with the exception of a
right-move that fell apart across the TN mtns, this activity has
been consistently streaming northwest west of the Appalachians. As
such, while isolated to widely scattered convection may initiate off
and on throughout the night across out forecast area, coverage
should remain relatively muted and intensity quite benign until the
cold front sweeps in from the west after sunrise. Considering the
continued poor antecedent hydro conditions across esp the NC mtns,
can't completely rule out a localized hydro problem overnight if
cells are able to train over the same area, but even those concerns
should largely hold off until ~late Sunday morning.

In term of the cold front and anticipated accompanying convective
band,  some timing discrepancies are noted in the hires models with
the HRRR abt 3 hrs ahead of the 4km NAM. This would make a big
difference as to available sbCAPE, but for now, believe the
pre-storm environment will feature sbCAPE values on the order of
800-1200 J/kg. Shear levels will also begin to increase and the
timing of the strongest shear still looks to be a little quicker
than the best destabilization, but enuf overlap is anticipated for a
line of stg/svr organized storms beginning before noon and
traversing east thru the afternoon. The main threats will be
damaging winds and large hail, however, a few tornadoes are not out
of the question as well with right turning hodos noted in the model
soundings while a llvl jet increases. There could be another
convective watch issued by the SPC for tomorrow afternoon.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 230 PM EDT Saturday: High pressure will begin to build into
the area Sunday leading to more tranquil conditions through Monday
night. Moisture will begin to return to the area by Tuesday as the
high moves of the east coast and return flow sets up. Highs both
Monday and Tuesday will be in the 60s in the Piedmont and mountain
valleys.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 230 pm EDT Saturday: A broad trof will dig into the middle of
the country for the middle of the week, shifting into the
northeastern states by late week. Expect showers and some
thunderstorms for our area Wednesday and Wednesday night. A cold
front will move through bringing much cooler conditions into the
area on Thursday and Friday.

Temperatures at or below freezing appear possible Friday morning
across the forecast area. Since the frost/freeze program will begin
again on April 1 for northeast Georgia, the SC foothills and
Piedmont and the southern NC foothills and Piedmont, headlines may
be needed Friday morning.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Convective coverage has diminished this
evening to just a couple of isolated cells near KGMU/KGSP. Once this
activity clears those two terminals, additional development
overnight doesn't appear likely, especially in light of the cooler/
relatively stable air that has overspread the Terminal Forecast Area
in the wake of this afternoon's convection. Nevertheless, chances
are sufficient to include a VCSH for much of the overnight at all
terminals. Confidence is low regarding cig/visby trends overnight,
as cool/relatively stable air mass gradually becomes displaced by
one with higher surface dewpoints. Confidence is relatively high in
low cigs...IFR or worse developing near KHKY, but confidence
decreases farther south, and will generally feature MVFR conditions
developing at the other sites. Shower/tstorm chances increase again
from late Sunday morning into the afternoon, warranting at least
Prob30s for TSRA at the terminals.

Winds will generally remain light NE at most locales this evening,
but gradually return to the SW late tonight. Winds will increase to
10 to 15 kts by late Sunday morning, with gusts as high as 30 kts
possible during the afternoon.

Outlook: VFR conds return Mon with a couple more moist systems and
flight restrictions possibly affecting the region as early as Tue.

Confidence Table...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       High 100%     Med   79%     High 100%     High 100%
KGSP       High 100%     High  84%     Med   79%     High  98%
KAVL       High  92%     High 100%     High  98%     High  97%
KHKY       High 100%     High  82%     Med   70%     High  82%
KGMU       High 100%     High  87%     Med   75%     High  98%
KAND       High 100%     High 100%     Med   69%     High  90%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Flash Flood Watch through Sunday evening for NCZ033-048>053-
     058-059-062>065-501-503-505-507-509.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...JDL/SBK
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...JDL

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
1050 PM EDT Sat Mar 27 2021

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-290300-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-
Union NC-Greater Caldwell-Greater Burke-Eastern McDowell-
Greater Rutherford-Eastern Polk-Oconee Mountains-Pickens Mountains-
Greenville Mountains-Greater Oconee-Greater Pickens-
Greater Greenville-Spartanburg-Cherokee-York-Anderson-Abbeville-
Laurens-Union SC-Chester-Greenwood-
1050 PM EDT Sat Mar 27 2021

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

.DAY ONE...Tonight.

Isolated thunderstorms will remain possible through the overnight.
The main threats with these storms will be from cloud to ground
lightning and locally heavy rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

A line of thunderstorms is expected to cross the area from west to
east during the late morning to mid-afternoon hours on Sunday.
Damaging winds will be the main threat, but a few storms may produce
large hail, as well.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-048>053-058-059-062>065-501-503-505-507-509-290300-
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
Rutherford Mountains-Polk Mountains-
1050 PM EDT Sat Mar 27 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH SUNDAY EVENING...

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

In addition to the flooding threat, isolated thunderstorms will
remain possible through the overnight. The main threats with these
storms will be from cloud to ground lightning and locally heavy
rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

A line of thunderstorms is expected to cross the area from west to
east during the late morning to mid-afternoon hours on Sunday.
Damaging winds will be the main threat, but a few storms may produce
large hail, as well.

.SPOTTER INFORMATION STATEMENT...

None.

Lane

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
735 PM EDT Sat Mar 27 2021

SCZ005>007-280000-
Greater Pickens SC-Spartanburg SC-Greater Greenville SC-
735 PM EDT Sat Mar 27 2021

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL GREENVILLE...WEST
CENTRAL SPARTANBURG AND EAST CENTRAL PICKENS COUNTIES UNTIL 800 PM
EDT...

At 735 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles northeast of Easley, or near Berea, moving east at 35 mph.

Locations to be impacted include...
Greenville Downtown, Easley, Greenville Eastside, West Greenville,
Greer, Mauldin, Taylors, Berea, Five Forks and Welcome.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3478 8246 3480 8246 3482 8248 3480 8253
      3481 8260 3496 8257 3497 8256 3496 8217
      3474 8223
TIME...MOT...LOC 2335Z 276DEG 29KT 3489 8252

RM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
847 PM EDT Sat Mar 27 2021

SCZ011-012-019-280130-
Laurens SC-Abbeville SC-Greenwood SC-
847 PM EDT Sat Mar 27 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN LAURENS...
SOUTHEASTERN ABBEVILLE AND GREENWOOD COUNTIES UNTIL 930 PM EDT...

At 847 PM EDT, Doppler radar was tracking a strong thunderstorm 14
miles south of Abbeville, or 7 miles west of Troy, moving northeast
at 45 mph.

Locations to be impacted include...
Greenwood, Abbeville, Ninety Six, Cokesbury, Hodges, Troy, Lake
Greenwood State Park, Lake Greenwood, Greenwood State Park and Ninety
Six Historic Site.

Wind gusts up to 45 mph and half inch hail will be possible in these
areas.

LAT...LON 3406 8233 3406 8244 3408 8248 3407 8253
      3441 8212 3422 8193 3420 8194 3420 8193
      3418 8192 3418 8191 3416 8190 3398 8221
      3402 8225 3397 8231
TIME...MOT...LOC 0047Z 229DEG 38KT 3398 8243

RM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
131 AM EDT Sun Mar 28 2021

NCZ082-280600-
Union NC-
131 AM EDT Sun Mar 28 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN UNION COUNTY UNTIL 200
AM EDT...

At 130 AM EDT, Doppler radar was tracking a strong thunderstorm 8
miles northeast of Lancaster, or 5 miles northwest of Buford, moving
northeast at 30 mph.

Locations to be impacted include...
Monroe, Mineral Springs, Wingate, Unionville, Jaars and Trinity.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

&&

LAT...LON 3482 8079 3485 8079 3507 8053 3481 8032
TIME...MOT...LOC 0530Z 232DEG 26KT 3482 8067

MOORE