Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
357 AM EDT Fri Mar 26 2021

.SYNOPSIS...
A cold front slowly pass through the area today, but stalls out just
south of the region tonight. This will allow an active pattern to
continue this weekend as the front lifts back north on Saturday,
then another cold front slides through the area on Sunday. Cool and
dry high pressure returns early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 AM EDT Friday: Based on radar trends and with coordination
with SPC and FFC/CAE offices, a Tornado Watch has been issued
for the Upper Savannah Valley counties (except Rabun/Habersham,
which are now behind the convection). The watch is in effect till
7 AM EDT this morning. Despite a cold pool holding on, convection
has shown some tight rotation coming off the GA Mountains. There
is more convection blossoming across the Atlanta metro area,
and will arrive over the next couple of hours. The cold pool
may erode and allow this convection to survive further north
and east. Meanwhile, continued heavy rain from Habersham County
NE along the escarpment is causing flash flooding concerns. No
changes were made to the Flash Flood Watch, which is in effect till
8 AM EDT. Guidance is in good agreement that a fairly solid band
of showers and embedded tstms will slowly cross the FA from west
to east thru mid-morning. Overall, expect a lack of instability
better antecedent conditions to limit the flood and tornado threat
from the I-26 corridor east. But conditions will be watched closely.

Otherwise, a frontal boundary should push out of the region by 18z
today as sfc high builds in to the NW and we enter a post-frontal
environment by the very end of the forecast period. Drier weather
will prevail, with highs in the low 80s in most locations outside
the mountains and 70s in the higher elevations. One factor that
can play a role is how fast the cold front exits the region and
allows for the clouds to scour out.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 345 AM EDT Friday: Due to active weather, didn't have time
to make much changes to the short term forecast. Unfortunately,
active weather pattern will continue, as another shortwave trough
carves out and helps shift the longwave trough axis east. A warm
front will lift north across the area on Saturday, likely bringing
a round of showers and possibly some embedded tstms. Fortunately,
any storms that develop should be elevated and the severe threat
looks low. Temps will be not as warm as Friday, thanks in part
due to mostly cloudy skies.

The warm front should lift north of the area by early Sunday,
and there is little indication of any wedge. Guidance is in good
agreement on a cold front crossing the area during the day Sunday,
and could line up well with peak heating. There is definitely
a concern for another round of organized severe tstms with this
front. Bulk shear will be strong thanks to an intense LLJ. Can't
rule out a quasi-linear and/or supercell storm mode. So in light
of that, the new SPC Day 3 Convective Outlook has the entire FA
in a Slight Risk. Will plan to update the threat mention in the
HWO. Otherwise, Sunday will be warm, and even feel a little humid,
if dewpts can get into the 60s. Highs in the mid 70s to 80 east
of the mountains. Temps drop back to near-normal Sunday night in
the wake of the cold front.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 12 AM EDT Friday: Good agreement amongst global models
provides above normal confidence in the extended period. The
progressive pattern will continue into next week. A cool
continental air mass will ride in on the tail of Sunday's cold
front, but full insolation and downslope flow off the southern
Appalachians will support highs still reaching the 70s for many on
Monday. Breezy but sub-advisory west/northwest winds should
gradually weaken late in the day. A transient 1030 mb high will
maintain the dry air mass and large diurnal swing in temperatures
into Tuesday. By Wednesday, return flow behind the high will support
increasing low level moisture off the Atlantic basin for at least
increasing clouds for southern areas if not supporting some shower
activity.

Probably the biggest story is the emergence of a full latitude
trough and associated frontal system to impact the area late in the
work week. It is too early for the details but this has the
potential to be a vigorous cold front with widespread precipitation.
Temperatures will likely fall below normal late next week in
response to the Canadian air mass settling into the region.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Continued below normal confidence in 06Z
TAFs mainly due to convection crossing the area during the pre-dawn
hours. Still expect a fairly solid line of showers and embedded
tstms to cross the area west to east. Expect the line to weaken
and shift south and east of all the TAF sites by 15z, with VFR
conditions expected the rest of the period. Cigs and visby are
highly variable at time of 06z TAF issuance, but expected to be
mainly MVFR to IFR thru about 12z, with rapid improvement in the
12-15z time frame. Winds are rather varialbe, and even favoring a
NE to E direction within a cold pool, despite guidance saying it
should be stiff out of the SE to SW. Still expect winds to favor a
SE direction, then shift to SW with low-end gusts during the midday
to late aftn hours. KAVL is the exception as winds turn to NW.

Outlook: Another system may bring showers Saturday with
thunderstorms possible by Sunday.

Confidence Table...

            08-14Z        14-20Z        20-02Z        02-06Z
KCLT       High  88%     High  90%     High 100%     High 100%
KGSP       High  89%     High  98%     High 100%     High 100%
KAVL       Med   71%     High 100%     High 100%     High 100%
KHKY       High  98%     High 100%     High 100%     High 100%
KGMU       High  84%     High 100%     High 100%     High 100%
KAND       High  96%     High 100%     High 100%     High 100%

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...None.
SC...None.

&&

SYNOPSIS...ARK
NEAR TERM...ARK
SHORT TERM...ARK
LONG TERM...Munroe
AVIATION...ARK

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
511 AM EDT Fri Mar 26 2021

GAZ029-NCZ057-071-072-082-SCZ009-011>014-019-270915-
Elbert-Rowan-Mecklenburg-Cabarrus-Union NC-York-Abbeville-Laurens-
Union SC-Chester-Greenwood-
511 AM EDT Fri Mar 26 2021

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

.DAY ONE...Today and tonight.

Scattered thunderstorms will continue across the lower Piedmont of
the Upstate and northeast Georgia, as well as the southern NC
Piedmont through the morning hours. Any thunderstorm will be capable
of cloud-to-ground lightning, strong gusty winds, and torrential
rainfall. A few storms could briefly become severe with large hail
and damaging wind gusts.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Another round of thunderstorms is expected on Sunday. Some of these
storms may become severe, producing damaging wind and large hail.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Please relay any information about
observed severe weather to the NWS while following all local, state,
and CDC guidelines.

GAZ010-017-018-026-028-NCZ033-035>037-048>053-056-058-059-062>065-
068>070-501>510-SCZ001>008-010-270915-
Rabun-Habersham-Stephens-Franklin-Hart-Avery-Alexander-Iredell-Davie-
Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Catawba-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Cleveland-Lincoln-Gaston-Caldwell Mountains-Greater Caldwell-
Burke Mountains-Greater Burke-McDowell Mountains-Eastern McDowell-
Rutherford Mountains-Greater Rutherford-Polk Mountains-Eastern Polk-
Oconee Mountains-Pickens Mountains-Greenville Mountains-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-Anderson-
511 AM EDT Fri Mar 26 2021

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

.DAY ONE...Today and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Another round of thunderstorms is expected on Sunday. Some of these
storms may become severe, producing damaging wind and large hail.

.SPOTTER INFORMATION STATEMENT...

None.

ARK

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
401 AM EDT Fri Mar 26 2021

GAZ029-SCZ011-019-260830-
Elbert GA-Abbeville SC-Greenwood SC-
401 AM EDT Fri Mar 26 2021

...A STRONG THUNDERSTORM WILL IMPACT ELBERT...ABBEVILLE AND WEST
CENTRAL GREENWOOD COUNTIES UNTIL 430 AM EDT...

At 401 AM EDT, Doppler radar was tracking a strong thunderstorm over
Elberton, moving east at 60 mph.

Locations to be impacted include...
Abbeville, Elberton, Calhoun Falls, Due West, Lake Secession,
Lowndesville, Lake Strom Thurmond, Russell State Park, Middleton and
Lake Russell.

Wind gusts up to 45 mph, half inch 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.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3401 8291 3401 8294 3403 8294 3405 8299
      3410 8304 3411 8303 3415 8306 3417 8310
      3425 8274 3421 8274 3428 8263 3435 8233
      3409 8218 3406 8236 3406 8244 3408 8248
      3407 8253 3401 8259 3399 8287
TIME...MOT...LOC 0801Z 255DEG 60KT 3411 8287

MOORE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
414 AM EDT Fri Mar 26 2021

SCZ006-007-012-013-260845-
Laurens SC-Union SC-Spartanburg SC-Greater Greenville SC-
414 AM EDT Fri Mar 26 2021

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL LAURENS...SOUTHEASTERN
GREENVILLE...SOUTHEASTERN SPARTANBURG AND WESTERN UNION COUNTIES
UNTIL 445 AM EDT...

At 413 AM EDT, Doppler radar was tracking a strong thunderstorm 8
miles northwest of Laurens, or over Gray Court, moving northeast at
50 mph.

Locations to be impacted include...
Laurens, Union, Clinton, Woodruff, Buffalo, Gray Court, Rose Hill
State Park, Pacolet, Pauline and Enoree.

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...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3441 8196 3454 8228 3464 8226 3490 8174
      3461 8156
TIME...MOT...LOC 0813Z 245DEG 44KT 3460 8212

MOORE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
425 AM EDT Fri Mar 26 2021

SCZ013-014-260900-
Union SC-Chester SC-
425 AM EDT Fri Mar 26 2021

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL CHESTER AND SOUTHEASTERN
UNION COUNTIES UNTIL 500 AM EDT...

At 425 AM EDT, Doppler radar was tracking a strong thunderstorm 11
miles south of Union, or 5 miles northeast of Whitmire, moving east
at 75 mph.

Locations to be impacted include...
Chester, Carlisle, Rose Hill State Park, Chester State Park,
Blackstock, Leeds, Cornwell, Tuckertown and Santuc.

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...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3449 8157 3454 8166 3462 8169 3482 8107
      3482 8105 3455 8100 3457 8142 3450 8142
      3449 8144 3449 8148 3447 8151 3446 8155
TIME...MOT...LOC 0825Z 251DEG 63KT 3457 8156

MOORE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
429 AM EDT Fri Mar 26 2021

GAZ029-SCZ010-011-019-260900-
Elbert GA-Abbeville SC-Anderson SC-Greenwood SC-
429 AM EDT Fri Mar 26 2021

...A STRONG THUNDERSTORM WILL IMPACT ELBERT...SOUTHEASTERN
ANDERSON...ABBEVILLE AND NORTHWESTERN GREENWOOD COUNTIES UNTIL 500 AM
EDT...

At 428 AM EDT, Doppler radar was tracking a strong thunderstorm 9
miles east of Elberton, or near Lake Russell, moving east at 70 mph.

Locations to be impacted include...
Greenwood, Abbeville, Elberton, Calhoun Falls, Due West, Iva, Lake
Secession, Donalds, Cokesbury and Hodges.

Wind gusts up to 45 mph, half inch hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.

Lake Russell is in the path of this storm. Cloud to ground lightning
and gusty winds will create dangerous boating conditions.
Move to shore immediately.

Doppler radar indicates weak rotation with this storm. Spin-up of a
very brief, weak tornado cannot be ruled out. Be prepared to take
immediate action if a tornado is sighted or a Tornado Warning is
issued.

&&

LAT...LON 3399 8283 3398 8286 3401 8291 3402 8294
      3421 8290 3446 8232 3411 8205 3407 8230
      3406 8233 3406 8244 3408 8248 3407 8253
      3401 8259 3397 8275 3397 8279
TIME...MOT...LOC 0828Z 251DEG 63KT 3412 8269

MOORE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
455 AM EDT Fri Mar 26 2021

SCZ007-012-013-019-260930-
Laurens SC-Greenwood SC-Union SC-Spartanburg SC-
455 AM EDT Fri Mar 26 2021

...A CLUSTER OF THUNDERSTORMS WILL IMPACT LAURENS...SOUTHEASTERN
SPARTANBURG...SOUTHWESTERN UNION AND NORTHERN GREENWOOD COUNTIES
UNTIL 530 AM EDT...

At 455 AM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms along a line extending from 13 miles west of Laurens
to 6 miles northeast of Abbeville, and moving east at 60 mph.

Locations to be impacted include...
Greenwood, Laurens, Clinton, Ware Shoals, Joanna, Gray Court, Cross
Hill, Cokesbury, Waterloo and Hodges.

Wind gusts up to 45 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

Lake Greenwood is in the path of these storms. Cloud to ground
lightning and gusty winds will create dangerous boating conditions.
Move to shore immediately.

&&

LAT...LON 3422 8225 3427 8230 3434 8233 3441 8225
      3448 8232 3454 8224 3459 8224 3474 8171
      3453 8164 3437 8178 3430 8190 3424 8191
      3420 8194 3416 8224
TIME...MOT...LOC 0855Z 254DEG 52KT 3449 8227 3424 8230

MOORE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
520 AM EDT Fri Mar 26 2021

SCZ013-014-261000-
Union SC-Chester SC-
520 AM EDT Fri Mar 26 2021

...A STRONG THUNDERSTORM WILL IMPACT CHESTER AND SOUTHEASTERN UNION
COUNTIES UNTIL 600 AM EDT...

At 519 AM EDT, Doppler radar was tracking a strong thunderstorm 12
miles south of Union, or near Whitmire, moving east at 60 mph.

Locations to be impacted include...
Chester, Great Falls, Fort Lawn, Carlisle, Richburg, Chester State
Park, Rose Hill State Park, Blackstock, Fishing Creek Reservoir and
Leeds.

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...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3446 8156 3448 8155 3454 8165 3466 8169
      3482 8090 3479 8088 3471 8086 3464 8090
      3455 8087 3455 8097 3457 8142 3450 8142
      3449 8144 3449 8149 3445 8154
TIME...MOT...LOC 0919Z 254DEG 60KT 3454 8162

MOORE