Alert archive / South Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 67, NWS Greenville-Spartanburg, SC

July 16, 2021Chester County, Union County, South Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Jul 16, 2021, 12:58 PM EDT for Chester County, Union County, South Carolina. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 16, 2021, 12:58 PM EDT (16:58 UTC)
Expired
Jul 16, 2021, 1:30 PM EDT
In force
32 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Chester County, SC, Union County, SC

The radar

The Columbia radar (KCAE), 74 km from the middle of the area, began a volume at 16:58 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 5.0 hours before the alert went out and 226 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2021-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 172 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2021-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
172 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
1372 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

156 
WUUS52 KGSP 161658
SVRGSP
SCC023-087-161730-
/O.NEW.KGSP.SV.W.0067.210716T1658Z-210716T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
1258 PM EDT Fri Jul 16 2021

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for...
  Southwestern Chester County in Upstate South Carolina...
  Southeastern Union County in Upstate South Carolina...

* Until 130 PM EDT.

* At 1258 PM EDT, a severe thunderstorm was located 12 miles
  southeast of Union, or near Carlisle, moving northeast at 15 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor hail damage to vehicles is expected. Expect wind 
           damage to trees and power lines.

* Locations impacted include...
  Monarch Mill, Carlisle, Tuckertown, Leeds and Santuc. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

Brief damaging winds will blow down trees and power lines over small
areas. A brief period of large hail is also possible. Seek shelter
inside an interior room.

This storm is producing frequent and intense lightning. Turn off
electrical appliances. Do not use corded telephones. Do not take a
bath or shower.

This storm is also producing extremely heavy rainfall. Flooding of
drainage ditches and low lying areas may occur. Small streams will
rise rapidly. Do not drive through areas where water is flowing over
the road.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3446 8156 3448 8155 3453 8162 3453 8164
      3454 8166 3474 8159 3467 8132 3457 8137
      3457 8142 3450 8142 3450 8144 3449 8144
      3449 8149 3445 8154
TIME...MOT...LOC 1658Z 226DEG 13KT 3463 8143 

HAIL...1.00IN
WIND...60MPH
 
$$

CAC
2 follow-up statements
288 
WWUS52 KGSP 161715
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
115 PM EDT Fri Jul 16 2021

SCC023-161724-
/O.CAN.KGSP.SV.W.0067.000000T0000Z-210716T1730Z/
Chester SC-
115 PM EDT Fri Jul 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CHESTER COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning moved out of the 
warned area, therefore the warning has been cancelled.

LAT...LON 3446 8156 3448 8155 3453 8162 3453 8163
      3454 8166 3465 8144 3464 8142 3458 8143
      3457 8142 3453 8143 3450 8142 3450 8144
      3449 8144 3449 8149 3445 8154
TIME...MOT...LOC 1714Z 226DEG 13KT 3467 8138 

$$

SCC087-161730-
/O.CON.KGSP.SV.W.0067.000000T0000Z-210716T1730Z/
Union SC-
115 PM EDT Fri Jul 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR SOUTHEASTERN UNION COUNTY...

At 114 PM EDT, a severe thunderstorm was located 9 miles west of
Chester, or 7 miles northeast of Carlisle, moving northeast at 15
mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor hail damage to vehicles is expected. Expect wind 
         damage to trees and power lines.

Locations impacted include...
Carlisle and Tuckertown. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

Brief damaging winds will blow down trees and power lines over small
areas. A brief period of large hail is also possible. Seek shelter
inside an interior room.

This storm is producing frequent and intense lightning. Turn off
electrical appliances. Do not use corded telephones. Do not take a
bath or shower.

This storms is also producing extremely heavy rainfall. Flooding of
drainage ditches and low lying areas may occur. Small streams will
rise rapidly. Do not drive through areas where water is flowing over
the road.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3446 8156 3448 8155 3453 8162 3453 8163
      3454 8166 3465 8144 3464 8142 3458 8143
      3457 8142 3453 8143 3450 8142 3450 8144
      3449 8144 3449 8149 3445 8154
TIME...MOT...LOC 1714Z 226DEG 13KT 3467 8138 

HAIL...1.00IN
WIND...60MPH
 
$$

CAC
191 
WWUS52 KGSP 161723
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
123 PM EDT Fri Jul 16 2021

SCC087-161733-
/O.EXP.KGSP.SV.W.0067.000000T0000Z-210716T1730Z/
Union SC-
123 PM EDT Fri Jul 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN UNION COUNTY WILL
EXPIRE AT 130 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire. However heavy rain 
is still possible with this thunderstorm.

LAT...LON 3446 8156 3448 8155 3453 8162 3453 8163
      3454 8166 3465 8144 3464 8142 3458 8143
      3457 8142 3453 8143 3450 8142 3450 8144
      3449 8144 3449 8149 3445 8154
TIME...MOT...LOC 1723Z 226DEG 13KT 3469 8136 

$$

CAC

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 16, 10:30 AM EDT, 2 hours 28 minutes earlier.

Area forecast discussion, Jul 16, 10:30 AM EDT, 2 hours 28 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1030 AM EDT Fri Jul 16 2021

.SYNOPSIS...
Warm high pressure will dominate the southeast for another day. A
broad trough of low pressure, and an associated surface cold front,
will then approach from the northwest over the weekend. The trough
and front will slowly settle southeast of the area early next week,
with modest drying and cooling from the north through mid-week.
Temperatures will likely rebound later in the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1015 AM EDT Friday: Grids are looking in pretty good shape
for the most part. Already warming up pretty quickly out there so
temperature trends looking pretty good for an uncomfortable
afternoon. That said, 12z KGSO sounding had a pretty thick warm
layer just below 500mb, and CAMs aren't all that impressed. Reduced
pops somewhat for this afternoon as it seems that cap might be
difficult to overcome, with the typical exception of course of the
mountains where pops were relatively unchanged, also very little
change down toward the Lakelands. Will keep an eye on trends and if
it looks like cap might break after all might have to readjust. With
any convection that does occur, with high PW values, main concern
would be heavy downpours and isolated flash flooding concerns.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 200 am EDT Friday: An active weather weekend is shaping up for
the western Carolinas and northeast Georgia as a high precipitable
water airmass remains over the region between offshore high pressure
and a deepening trough to the west. The upstream 500 mb trough axis
will dig from the Great Lakes to the Ohio River Valley over the
weekend, while an associated surface cold front pushes steadily
toward the Appalachians. Fairly robust diurnal convection is
expected ahead of the approaching trough axis both Saturday and
Sunday afternoon and evening as surface-based CAPE values bubble up
above 2000 J/kg each day with peak heating. In addition, slightly
better shear profiles will develop atop the area over the weekend,
with pockets of 25+ kt sfc to 3 km bulk shear. Upper forcing with
the approaching trough will improve as an upper jetlet stretches out
along the Appalachians, bringing increasing upper-level divergence
to the region, especially on Sunday. Shower and thunderstorm
coverage should maximize in the likely to categorical range both
days, especially over northern and western sections where the
forcing will be best. Isolated severe thunderstorms will be possible
both days, but with slightly greater chances on Sunday afternoon.
The hydro risk will steadily build as well over the weekend, with
any training of thunderstorms possibly leading to isolated flash
flooding in the high PWAT airmass. The increasing clouds will likely
limit maximum temperatures to near climo on Saturday and a category
below on Sunday.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 245 am EDT Friday: The slowly-passing eastern U.S. trough axis
will likely cross the southern Appalachians on Monday, but with more
questionable progress off the coastline on Tuesday. The associated
surface cold front will likely settle slowly southeast across the
forecast area during this period as well. The gradual decrease in
moisture and forcing across the region will require continued above
climo PoPs early next week, especially for the southeast half of the
area. Temperatures should dip at least a category below climo given
the clouds and the onset of modest thickness falls with the fropa.

Deep-layer northwest flow should then be in place Wednesday through
Thursday. However, enough boundary layer moisture may linger over
the region for diurnal isolated to scattered convection to fire once
again. Improving insolation mid to late week should permit
temperatures to gradually rebound to climo values, with typical July
conditions likely by next Thursday.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
At KCLT and Elsewhere: The rest of the morning should be mostly quiet
across the fcst area with light and vrb winds remaining calm at times
through the morning. Anticipate restrictions to continue at KAVL thru
roughly 14z with mountain valley fog/stratus already in place. Expect
the other taf sites to remain VFR this morning, but cannot rule out a
few brief restrictions over the next few hours. Otherwise, we can expect
another day of sct convection this aftn/evening, with overall coverage
not expected to exceed sct. As such, I maintained VCSH and PROB30s for
TSRA for the convective potential later today. Winds will remain SLY
to SWLY, except at KAVL, where a light NWLY wind this morning will
become SLY to SWLY this afternoon/evening.

Outlook: An unsettled pattern, with afternoon/evening showers and
thunderstorms and morning fog/low stratus, will persist thru the
weekend and into early next week. A front near the region may enhance
afternoon/evening convective coverage this weekend.

Confidence Table...

            14-20Z        20-02Z        02-08Z        08-12Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High  82%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     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...HG
NEAR TERM...JPT/TDP
SHORT TERM...HG
LONG TERM...HG
AVIATION...JPT
Hazardous weather outlook, Jul 16, 4:18 AM EDT, 8 hours 40 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
418 AM EDT Fri Jul 16 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-170830-
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-Oconee Mountains-
Pickens Mountains-Greenville Mountains-Greater Oconee-
Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York-
Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
418 AM EDT Fri Jul 16 2021

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 to develop across
the western Carolinas and northeast Georgia this afternoon and
evening. Threats from these storms will include gusty winds, locally
heavy rainfall, and occasional cloud-to-ground lightning strikes.
The thunderstorms will diminish after midnight.

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

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

HG

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 16, 1:43 PM EDTSpecial Weather StatementGSPChester32 min
Jul 16, 1:57 PM EDTSpecial Weather StatementGSPNewberry33 min
Jul 16, 2:14 PM EDTSpecial Weather StatementGSPGreenwood31 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.