Alert archive / South Carolina / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 243, NWS Greenville-Spartanburg, SC

July 23, 2017Union County, South Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Jul 23, 2017, 4:38 PM EDT for Union County, South Carolina. It was in force for 33 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 23, 2017, 4:38 PM EDT (20:38 UTC)
Expired
Jul 23, 2017, 5:11 PM EDT
In force
33 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Union County, SC

The radar

The Greer radar (KGSP), 59 km from the middle of the area, began a volume at 20:39 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.

What was reported inside it

TimeReportWhereRemark
Jul 23, 4:40 PM EDTTSTM WND DMG4 Sw Union, SCTREES DOWN ALONG HIGHWAY 49 SOUTHWEST OF UNION.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 2 minutes after it went out.

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, 8.6 hours before the alert went out and 231 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 2017-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 636 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 2017-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
636 J/kg
Mixed-layer CIN
-125 J/kg
Mixed-layer LCL
1607 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

122 
WUUS52 KGSP 232038
SVRGSP
SCC087-232130-
/O.NEW.KGSP.SV.W.0243.170723T2038Z-170723T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
438 PM EDT SUN JUL 23 2017

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for...
  Central Union County in Upstate South Carolina...

* Until 530 PM EDT

* At 438 PM EDT, a severe thunderstorm was located 5 miles southwest
  of Union, or near Rose Hill State Park, moving east at 10 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...
  Union, Monarch Mill, Buffalo, Rose Hill State Park, Sedalia and
  Cross Keys.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3456 8168 3455 8169 3456 8170 3455 8172
      3461 8178 3473 8169 3472 8153 3454 8165
TIME...MOT...LOC 2038Z 278DEG 7KT 3466 8167 

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

KRENTZ
2 follow-up statements
391 
WWUS52 KGSP 232100
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
500 PM EDT SUN JUL 23 2017

SCC087-232130-
/O.CON.KGSP.SV.W.0243.000000T0000Z-170723T2130Z/
Union SC-
500 PM EDT SUN JUL 23 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHWESTERN UNION COUNTY...

At 500 PM EDT, a severe thunderstorm was located 4 miles south of
Union, or 4 miles northeast of Rose Hill State Park, moving east at
10 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...
Rose Hill State Park, Sedalia and Cross Keys. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3456 8168 3455 8169 3456 8170 3455 8172
      3461 8178 3466 8174 3459 8161 3454 8165
TIME...MOT...LOC 2100Z 278DEG 7KT 3465 8162 

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

KRENTZ
954 
WWUS52 KGSP 232111
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
511 PM EDT SUN JUL 23 2017

SCC087-232121-
/O.CAN.KGSP.SV.W.0243.000000T0000Z-170723T2130Z/
Union SC-
511 PM EDT SUN JUL 23 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN UNION COUNTY IS
CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore the warning has
been cancelled.

LAT...LON 3456 8168 3455 8169 3456 8170 3455 8172
      3461 8178 3466 8174 3459 8161 3454 8165
TIME...MOT...LOC 2110Z 278DEG 7KT 3465 8159 

$$

KRENTZ

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 23, 2:38 PM EDT, 2 hours earlier.

Area forecast discussion, Jul 23, 2:38 PM EDT, 2 hours before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
238 PM EDT Sun Jul 23 2017

.SYNOPSIS...
A cold front will become stationary from west to east across our
region through the middle of the week then dissipate.  This should
result in a little cooler temperature and better chances for rain
over the next few days.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 235 PM EDT Sunday: Convection will move off the Blue Ridge and
SE across the foothills and piedmont of the Carolinas and NE GA
through early evening. Some of these storms will be severe with
damaging downbursts the main threat but isolated large hail cannot
be ruled out. The NC Southern Piedmont and eastern Upstate look to
have the best chance of seeing severe storms given the movement of
the current broken line of severe storms. That said, there is plenty
of instability and DCAPE over NE GA and the western Upstate, so
those areas are vulnerable as well.

Convection diminishes this evening as the line moves SE of the area.
However, there will be more MCS convection moving into the NC
mountains overnight. The latest CAM guidance shows this convection
diminishing as it moves into the foothills and dissipating before
reaching the piedmont. Have followed these trends in the PoP
forecast. Mountain valley fog, some dense, is expected again and
locations outside of the mountains that receive rainfall may see
some as well. Lows will again be above normal but not quite as warm
as last night.

Convection redevelops Monday as outflow boundaries from the
overnight MCS move across the area. Coverage will be better along
and south of the I-85 corridor where the timing of the boundary
movement will coincide with the higher instability. North of the
corridor instability will be much less leading to only isolated
coverage at best. DCAPE and sfc delta theta-E values while still on
the high side, will not be as high as Sunday. Instability will reach
moderate levels but just barely. Therefore, the chance of severe
storms will be less but not non-existent. Highs will be in the lower
90s outside of the mountain, and while still humid, heat index
values should remain below 100.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 200 PM Sunday: A weak and nearly stationary cold front
will remain over central GA and SC Monday night into Tuesday,
immediately south of the CWFA. Aloft, we will remain somewhat
under the influence of the northeast CONUS trough, though
without significant embedded vorticity in play early in the
period. More abundant moisture will be present over the south,
near the front, which could increase cloud cover. But otherwise it
appears conditions will be close to climatology, with seasonably
modest instability and weak shear producing a small pulse severe
threat. Partial thicknesses change little from Monday, so max
temps should be similar.

Tuesday night, high pressure will shift into New England in the
wake of the upper trough. A weak upper low is shown to cut off
and remain over the Carolina coast, and allows enough vorticity
to persist over the area that isolated t-storms still could fire
overnight across mainly the Piedmont. The eastward push of the high
will bring cooler air south into the area, which virtually all
guidance indicates will knock max temps down to a couple degrees
below normal, in conjunction with increased cloud cover. Nonetheless
consensus SBCAPE values remain fairly large given still-elevated
sfc dewpoints and good lapse rates afforded by the upper low. PoPs
peak above climo and pulse threats return once again.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 145 PM Sunday: The medium range begins Wednesday evening with
a weak closed off 500mb low over the Carolinas and Georgia. As the
next northern stream shortwave crosses the Great Lakes on Thursday,
it kicks this weak low off to the east with the 500mb trough digging
over the East through the weekend. As the Great Lakes shortwave
moves to far eastern Canada, the associated cold front moves slowly
southeast. This front should be nearing the Ohio River early Friday.
As the front approaches from the north, frontal associated
convection will increase first across areas along and north of I-40
Friday afternoon and then spread across much of the rest of the area
Friday evening. The front becomes stationary west to east across our
region through the weekend. The eventual location of the axis of the
trough next weekend varies among the models. This axis location will
have significant influence on our weather. Also, mesoscale
convective systems are expected to develop near the Rockies or
northern Plains states and track southeast in the northwest 500mb
flow toward our region of the nation. Therefore, our weather will
remain unsettled through the weekend. Temperatures will be near
normal.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Line of convection developing across the NC
mountains and becoming strong to severe. Have gone pessimistic with
the TAFs in response and indicate VRB winds and TSRA in a TEMPO.
Storms could linger a while in the evening outside of the mountains
so have VFR VCTS in place. Guidance not very favorable for
restrictions outside of the mountain valleys overnight, so have
limited them to KAVL. That said, they will be possible as most
locations will receive rainfall. Scattered convection expected
Monday for all but KHKY. SW wind today becomes light overnight, then
W to SW for Monday.

Outlook: Increasing chances of convection expected through the
middle of next week ahead of a series of weakening cold fronts.
Overnight restrictions will continue in the mountain valleys with
chance increasing elsewhere.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High  92%     High  96%
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 and ensemble forecasts
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...RWH
SHORT TERM...Wimberley
LONG TERM...DEO
AVIATION...RWH
Hazardous weather outlook, Jul 23, 5:57 AM EDT, 10 hours 41 minutes before
Hazardous Weather Outlook...CORRECTED
National Weather Service Greenville-Spartanburg SC
557 AM EDT Sun Jul 23 2017

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-241000-
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-
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-Chester-Greenwood-
557 AM EDT Sun Jul 23 2017

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

.DAY ONE...Today and Tonight.

Scattered to numerous thunderstorms are expected to develop across
the area this afternoon into early evening. The air mass in place is
expected to become moderately to highly unstable. Therefore, many
of the storms may become severe, capable of producing damaging
wind gusts and large hail. This is in addition to the usual threat
of cloud- to-ground lightning and locally heavy rainfall. While
most of the activity will diminish after sunset, additional
thunderstorms may move into western North Carolina from Tennessee
and Virginia overnight, bringing a second round of thunderstorms
producing lightning and gusty winds.

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

..Monday...No hazardous weather is expected at this time.
..Tuesday...No hazardous weather is expected at this time.
..Wednesday...No hazardous weather is expected at this time.
..Thursday...No hazardous weather is expected at this time.
..Friday...No hazardous weather is expected at this time.
..Saturday...No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

ARK

In the hours before

Local storm report, Jul 23, 3:46 PM EDT, 52 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
346 PM EDT SUN JUL 23 2017

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

0226 PM     TSTM WND DMG     3 ENE LAKE LURE         35.46N 82.16W
07/23/2017                   RUTHERFORD         NC   911 CALL CENTER

            NUMEROUS TREES AND POWERLINES DOWN FROM LAKE LURE TO
            SHINGLE HOLLOW.

0238 PM     TSTM WND DMG     RUTHERFORDTON           35.36N 81.96W
07/23/2017                   RUTHERFORD         NC   911 CALL CENTER

            A TREE ON A HOUSE.

&&

OUTLAW
Special weather statement, Jul 23, 3:50 PM EDT, 48 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
350 PM EDT SUN JUL 23 2017

NCZ082-232015-
Union NC-
350 PM EDT SUN JUL 23 2017

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN UNION COUNTY UNTIL
415 PM EDT...

At 350 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles east of Monroe, or near Marshville, moving east at 15 mph.

Locations to be impacted include...
Marshville and Sturdivants.

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

LAT...LON 3484 8032 3486 8046 3509 8039 3507 8029
TIME...MOT...LOC 1950Z 291DEG 12KT 3498 8035

KRENTZ
Local storm report, Jul 23, 4:11 PM EDT, 27 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
411 PM EDT SUN JUL 23 2017

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

0345 PM     TSTM WND GST     CONCORD                 35.41N 80.59W
07/23/2017  E60 MPH          CABARRUS           NC   TRAINED SPOTTER

            TRAINED SPOTTER ESTIMATED 60 MPH WINDS. NICKEL SIZED HAIL
            ALSO OBSERVED.

&&

TPALMER
Special weather statement, Jul 23, 4:11 PM EDT, 27 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
411 PM EDT SUN JUL 23 2017

NCZ057-071-072-232045-
Rowan NC-Cabarrus NC-Mecklenburg NC-
411 PM EDT SUN JUL 23 2017

...A STRONG THUNDERSTORM WILL IMPACT CABARRUS...EAST CENTRAL
MECKLENBURG AND SOUTHEASTERN ROWAN COUNTIES UNTIL 445 PM EDT...

At 411 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles east of Downtown Concord, or near Mt Pleasant, moving northeast
at 35 mph.

Locations to be impacted include...
Downtown Concord, Kannapolis, West Concord, Harrisburg, Granite
Quarry, Rockwell, Mt Pleasant, Faith, Reedy Creek Park and Charlotte
Motor Speedway.

Wind gusts up to 50 mph and dime size hail 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.

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.

&&

LAT...LON 3550 8030 3519 8051 3521 8055 3520 8056
      3527 8086 3572 8033 3568 8033 3563 8029
      3563 8027 3559 8021 3555 8021 3551 8018
TIME...MOT...LOC 2011Z 227DEG 30KT 3542 8050

KRENTZ
Local storm report, Jul 23, 4:16 PM EDT, 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
416 PM EDT SUN JUL 23 2017

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

0355 PM     TSTM WND DMG     ROCK HILL               34.94N 81.03W
07/23/2017                   YORK               SC   TRAINED SPOTTER

            TREES DOWN, ESTIMATED 60 MPH WINDS. 1/2 INCH HAIL ALSO
            REPORTED.

&&

TPALMER
Local storm report, Jul 23, 4:24 PM EDT, 14 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
424 PM EDT SUN JUL 23 2017

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

0405 PM     TSTM WND DMG     2 ESE PINEVILLE         35.07N 80.85W
07/23/2017                   MECKLENBURG        NC   SOCIAL MEDIA

            TREES DOWN AND PATIO FURNITURE BLOWN OVER.

&&

TPALMER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 2:46 PM EDTSevere Thunderstorm WarningGSPCherokee44 min
Jul 23, 3:03 PM EDTSpecial Weather StatementGSPPickens42 min
Jul 23, 3:06 PM EDTSpecial Weather StatementGSPChester24 min
Jul 23, 3:18 PM EDTSevere Thunderstorm WarningGSPOconee, Pickens42 min
Jul 23, 3:20 PM EDTSevere Thunderstorm WarningGSPChester40 min
Jul 23, 3:42 PM EDTSpecial Weather StatementGSPUnion, York33 min
Jul 23, 3:58 PM EDTSevere Thunderstorm WarningGSPSpartanburg, Union47 min
Jul 23, 4:06 PM EDTSevere Thunderstorm WarningGSPAnderson, Oconee, Pickens39 min
Jul 23, 4:20 PM EDTSevere Thunderstorm WarningGSPChester, Union, York40 min
Jul 23, 4:29 PM EDTAreal Flood AdvisoryGSPYork2 hr
Jul 23, 4:46 PM EDTAreal Flood AdvisoryGSPChester119 min
Jul 23, 5:12 PM EDTSevere Thunderstorm WarningGSPLaurens33 min
Jul 23, 5:32 PM EDTSpecial Weather StatementGSPLaurens43 min
Jul 23, 6:06 PM EDTSpecial Weather StatementGSPGreenwood24 min
Jul 23, 6:36 PM EDTSpecial Weather StatementGSPGreenwood24 min
Jul 23, 7:01 PM EDTSpecial Weather StatementGSPAbbeville29 min
Jul 23, 7:04 PM EDTSpecial Weather StatementGSPGreenwood26 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2017Every severe thunderstorm warning in 2017

Sources

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