Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
303 PM EDT Tue May 4 2021

.SYNOPSIS...
Expect chances for showers and thunderstorms to continue across the
region until a cold front crosses from the west on Wednesday,
After the front passes, high pressure will bring cooler
temperatures into Saturday.  The high will shift to our east over
the weekend, resulting in warmer temperatures into early next week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 255 PM EDT Tuesday: The latest RADAR mosaic currently has a
broad line of thunderstorms pushing east across the Upstate and
Piedmont and widespread showers behind it. Otherwise, the main
concern is the ongoing convection that is producing isolated strong
to severe thunderstorms across the CWA this aftn/evening. Severe or
not, coverage should remain numerous into the early part of the
evening. The synoptic scale models might be overdoing the upscale
growth potential this evening with the convection moving in from the
west, so the precip probs will be tailed off after 00Z for the time
being, eventually dropping back to the mtns overnight, with some
potential for more storms reaching the NC mtns toward daybreak
Wednesday, ahead of the approaching cold front. The flash flood
potential will be higher today after the rains of yesterday, but
still not high enough to consider any watches at this time. Temps
will rebound back above normal again tomorrow.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 130 PM EDT Tuesday: Weakening low pressure is already passing
well to our north and off the east coast on Wednesday evening,
dragging a trailing cold front out of the Carolinas overnight.
Moisture appears lacking with this system, however, with all the
deterministic models depicting better PWATs mainly to our north.
By Thursday morning after sunrise, the front should have cleared
our CWA anyway, and precipitation should have let up except
perhaps for a few upslope areas in the western Appalachians.
Dry northwest flow takes hold from there.

Conditions should remain calm on Thursday, with a zonal, undisturbed
500mb pattern persisting through the day, until a a deepening
shortwave digs out of the Midwest.  This should provide modest
midlevel forcing Thursday night, tapering off Friday morning as the
vort max passes over our CWA and heights begin to recover again.
Precip associated with this fropa will be severely limited, owing to
the moisture-starved environment in which that forcing takes place.
Moreover, despite temps dropping into the mid/upper 30s in a few
high-elevation spots in the mountains, a steady wind paired with
a few weak gusts should prevent much frost formation.

Heights continue to rise on Friday as northwesterly CAA continues
and high pressure builds into the area.  We should transition to
a weak ridging regime for the weekend, allowing temps to creep
back toward normal, although still staying below normal through
Friday evening.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 145 PM EDT Tuesday: Dry high pressure continues to dominate
the forecast on Saturday as weak ridging pushes through the eastern
U.S.  We'll see a wind shift to southerly return flow early Sunday,
as the high center drifts east of us and meanders off the coast.
So, moisture content on Sunday will be greater than on the previous
two days, as a lifting warm front induces modest moisture advection
into the region.  Sunday night, a shortwave pushes across the
region, and heights begin to fall again.  We should see a cold
fropa Sunday night or Monday morning, which will yield our next
opportunity for moderate PoPs, after which the boundary will stall
and provide a focus for additional activity later in the week.
Guidance has not yet reached a consensus this far out, but in broad
strokes we can expect the boundary to meander north and south,
allowing for another potentially active week.

Temps will creep upward over the weekend, returning to near-
or slightly above-normal by Sunday afternoon.  Saturday morning
especially may present a frost threat in the mountains, as temps
at high elevations may drop into the 30s beneath a fairly calm
prevailing wind.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Vrb ceiling restrictions will continue thru
much of the 18z taf period as the bndy layer will remain particularly
moist. All taf sites will likely see another round of showers and
thunderstorms, most likely during the middle to late afternoon, which
are largely handled with TEMPO groups. It appears that we'll see a
break in the action during the later in the aftn or early evening
where conditions may improve to VFR, but then another round of
convection develops this evening which are handled with another
round of TEMPOs. Winds will remain SLY to SWLY thru the period,
with sporadic gusts this aftn and again tomorrow aftn, especially
in the vicinity of any thunderstorms. There is some indication of
cig/visby restrictions redeveloping before daybreak tomorrow, but
confidence remains low at this time. For the time being, I kept an
MVFR cig at the Upstate sites from roughly 08 to 14z.

Outlook: The chances for restrictions will persist thru Wednesday
as a cold front moves into the area and crosses the region. Another
lull in convective activity is expected for the end of the week.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High  98%     High  93%     High  93%     High  98%
KGSP       High  97%     High  93%     High  81%     High  96%
KAVL       High  96%     High  98%     High 100%     High  95%
KHKY       High  92%     High  87%     High  98%     High 100%
KGMU       High  87%     High  94%     High  82%     High  96%
KAND       High  93%     High  95%     Med   72%     High  87%

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...DEO
NEAR TERM...JPT
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...JPT

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
136 PM EDT Tue May 4 2021

GAZ010-017-018-026-028-029-NCZ033-035-036-048>053-056-058-059-
062>065-068>070-501>510-SCZ001>008-010>013-019-050400-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Alexander-
Iredell-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-Abbeville-Laurens-
Union SC-Greenwood-
136 PM EDT Tue May 4 2021

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

.DAY ONE...This afternoon and tonight.

A cold front approaching from the west will be the trigger for
another round of strong to severe thunderstorms during mainly the
afternoon hours today. The main threats will be damaging wind gusts
and large hail. An isolated brief tornado cannot be ruled out across
the southern Piedmont. The storms will increase the threat for
isolated flash flooding as well across areas that experience multiple
rounds of rainfall.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Hazardous weather is not expected at this time.

.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.

NCZ037-057-071-072-082-SCZ009-014-050400-
Davie-Rowan-Mecklenburg-Cabarrus-Union NC-York-Chester-
136 PM EDT Tue May 4 2021

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

.DAY ONE...This afternoon and tonight.

A cold front approaching from the west will be the trigger for
another round of strong to severe thunderstorms during mainly the
afternoon hours today. The main threats will be damaging wind gusts
and large hail. An isolated brief tornado cannot be ruled out across
the southern Piedmont. The storms will increase the threat for
isolated flash flooding as well across areas that experience multiple
rounds of rainfall.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

The cold front could trigger isolated severe thunderstorms along and
east of the I-77 corridor again on Wednesday as it crosses the
region.

.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.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
251 PM EDT Tue May 4 2021

NCZ071-SCZ008-009-013-014-041930-
Mecklenburg NC-York SC-Cherokee SC-Union SC-Chester SC-
251 PM EDT Tue May 4 2021

...A STRONG THUNDERSTORM WILL IMPACT WESTERN MECKLENBURG...NORTHERN
CHESTER...YORK...SOUTHEASTERN CHEROKEE AND NORTHEASTERN UNION
COUNTIES UNTIL 330 PM EDT...

At 251 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles northeast of Union, or 4 miles north of Monarch Mill, moving
east at 50 mph.

Locations to be impacted include...
Rock Hill, Union, York, Chester, Tega Cay, Newport, Lesslie, Monarch
Mill, Jonesville and Lockhart.

Wind gusts up to 50 mph and pea size hail will be possible in these
areas.

LAT...LON 3468 8164 3485 8169 3515 8103 3484 8088
      3483 8090 3482 8090 3479 8088 3475 8088
      3473 8087
TIME...MOT...LOC 1851Z 255DEG 43KT 3479 8158

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
305 PM EDT Tue May 4 2021

GAZ028-029-SCZ006-010>012-019-041945-
Elbert GA-Hart GA-Laurens SC-Anderson SC-Abbeville SC-Greenwood SC-
Greater Greenville SC-
305 PM EDT Tue May 4 2021

...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL ELBERT...
SOUTHEASTERN HART...WESTERN LAURENS...SOUTHEASTERN GREENVILLE...
SOUTHEASTERN ANDERSON...CENTRAL ABBEVILLE AND NORTHERN GREENWOOD
COUNTIES UNTIL 345 PM EDT...

At 304 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles southeast of Hartwell, moving east at 55 mph.

Locations to be impacted include...
Hartwell, Abbeville, Greenwood, Belton, Honea Path, Ware Shoals, Due
West, Iva, Lake Secession and Cross Hill.

Wind gusts up to 55 mph and pea size hail will be possible in these
areas.

LAT...LON 3414 8293 3430 8302 3468 8218 3424 8194
TIME...MOT...LOC 1904Z 255DEG 49KT 3430 8283

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
321 PM EDT Tue May 4 2021

SCZ012-013-041945-
Laurens SC-Union SC-
321 PM EDT Tue May 4 2021

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL LAURENS AND SOUTHERN
UNION COUNTIES UNTIL 345 PM EDT...

At 321 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles south of Laurens, or 6 miles northeast of Waterloo, moving
northeast at 50 mph.

Locations to be impacted include...
Union, Laurens, Clinton, Monarch Mill, Joanna, Cross Hill, Rose Hill
State Park, Waterloo, Mountville and Kinards.

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

LAT...LON 3429 8201 3445 8211 3459 8187 3458 8186
      3460 8185 3475 8159 3451 8142 3450 8142
      3449 8144 3449 8149 3445 8154 3448 8156
      3453 8164 3452 8165 3446 8170 3444 8173
      3436 8179 3433 8185
TIME...MOT...LOC 1921Z 240DEG 42KT 3442 8198

WJM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
323 PM EDT TUE MAY 04 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0141 PM     TORNADO          2 NW ELBERTON           34.13N 82.89W
05/03/2021                   ELBERT             GA   NWS STORM SURVEY

            TREE DAMAGE AND ROOF COLLAPSE BETWEEN BEECHWOOD RD AND
            BOWMAN HWY WAS CAUSED BY EF1 TORNADO.

&&

WIMBERLEY

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
324 PM EDT Tue May 4 2021

NCZ057-071-072-042000-
Rowan NC-Cabarrus NC-Mecklenburg NC-
324 PM EDT Tue May 4 2021

...A STRONG THUNDERSTORM WILL IMPACT CABARRUS...CENTRAL MECKLENBURG
AND SOUTHWESTERN ROWAN COUNTIES UNTIL 400 PM EDT...

At 324 PM EDT, Doppler radar was tracking a strong thunderstorm near
Uptown Charlotte, or over The Plaza, moving northeast at 50 mph.

Locations to be impacted include...
Uptown Charlotte, Kannapolis, Downtown Concord, Huntersville, Central
Charlotte, Northeast Charlotte, East Charlotte, Northwest Charlotte,
West Concord and Mint Hill.

Wind gusts up to 45 mph will be possible in these areas.

LAT...LON 3522 8048 3520 8053 3521 8055 3518 8059
      3509 8083 3527 8097 3551 8076 3551 8074
      3553 8074 3557 8070 3538 8038
TIME...MOT...LOC 1924Z 240DEG 42KT 3521 8080

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
339 PM EDT Tue May 4 2021

NCZ071-082-SCZ009-014-042030-
Union NC-Mecklenburg NC-York SC-Chester SC-
339 PM EDT Tue May 4 2021

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN MECKLENBURG...
UNION...NORTHEASTERN CHESTER AND SOUTHEASTERN YORK COUNTIES UNTIL 430
PM EDT...

At 339 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Rock Hill, or 6 miles southwest of Lesslie, moving
east at 40 mph.

Locations to be impacted include...
Rock Hill, Monroe, South Charlotte, Matthews, Indian Trail,
Weddington, Fort Mill, Stallings, Unionville and Wesley Chapel.

Wind gusts up to 50 mph and pea size hail will be possible in these
areas.

LAT...LON 3482 8080 3486 8080 3486 8087 3483 8090
      3479 8088 3475 8088 3472 8109 3495 8118
      3506 8090 3501 8091 3499 8089 3492 8086
      3487 8088 3488 8080 3494 8078 3507 8090
      3521 8055 3520 8054 3481 8034
TIME...MOT...LOC 1939Z 258DEG 37KT 3484 8104

WJM