Alert archive / South Carolina / Tornado Warnings in 2020

Tornado Warning 25, NWS Columbia, SC

September 17, 2020Clarendon County, Sumter County, South Carolina

NWS Columbia, SC issued this tornado warning at Sep 17, 2020, 12:39 PM EDT for Clarendon County, Sumter County, South Carolina. It was in force for 33 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: Sep 17, 2020, 12:39 PM EDT (16:39 UTC)
Expired: Sep 17, 2020, 1:12 PM EDT
In force: 33 min
Issued by: NWS Columbia, SC
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

Counties Clarendon County, SC, Sumter County, SC

The radar

The Columbia radar (KCAE), 102 km from the middle of the area, began a volume at 16:39 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Sep 17, 10:20 AM EDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 4.7 hours before the alert went out and 103 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1154 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 652 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 188 m²/s²
0-3 km storm-relative helicity: 261 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 5.7

Open this sounding in Storm Lab

The text

As transmitted.

713 
WFUS52 KCAE 171639
TORCAE
SCC027-085-171730-
/O.NEW.KCAE.TO.W.0025.200917T1639Z-200917T1730Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Columbia SC
1239 PM EDT Thu Sep 17 2020

The National Weather Service in Columbia has issued a

* Tornado Warning for...
  Northeastern Clarendon County in central South Carolina...
  East central Sumter County in central South Carolina...

* Until 130 PM EDT.
    
* At 1239 PM EDT, a severe thunderstorm capable of producing a
  tornado was located 7 miles east of Alcolu, or 7 miles east of
  Manning, moving north at 30 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Woods Bay State Park around 110 PM EDT.

Other locations impacted by this tornadic thunderstorm include
Turbeville, Shiloh and Gable.

This includes Interstate 95 between mile markers 125 and 139.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! If you are outdoors, in a mobile home, or in a
vehicle, move to an interior room or closet on the lowest floor of a
sturdy building immediately.

&&

LAT...LON 3380 7995 3377 7999 3373 7998 3367 8001
      3368 8018 3395 8018 3396 8017 3395 7998
      3388 7994 3389 7992
TIME...MOT...LOC 1639Z 186DEG 25KT 3374 8009 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

JAQ

2 follow-up statements

705 
WWUS52 KCAE 171659
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
1259 PM EDT Thu Sep 17 2020

SCC027-085-171730-
/O.CON.KCAE.TO.W.0025.000000T0000Z-200917T1730Z/
Clarendon SC-Sumter SC-
1259 PM EDT Thu Sep 17 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 130 PM EDT FOR
NORTHEASTERN CLARENDON AND EAST CENTRAL SUMTER COUNTIES...
    
At 1259 PM EDT, a severe thunderstorm capable of producing a tornado
was located 7 miles southwest of Woods Bay State Park, or 14 miles
northeast of Manning, moving north at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Woods Bay State Park around 115 PM EDT.

Other locations impacted by this tornadic thunderstorm include
Turbeville and Shiloh.

This includes Interstate 95 between mile markers 132 and 139.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! If you are outdoors, in a mobile home, or in a
vehicle, move to an interior room or closet on the lowest floor of a
sturdy building immediately.

&&

LAT...LON 3382 8002 3383 8011 3396 8017 3395 7998
      3391 7996
TIME...MOT...LOC 1659Z 192DEG 23KT 3386 8006 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

JAQ

775 
WWUS52 KCAE 171712
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
112 PM EDT Thu Sep 17 2020

SCC027-085-171722-
/O.CAN.KCAE.TO.W.0025.000000T0000Z-200917T1730Z/
Clarendon SC-Sumter SC-
112 PM EDT Thu Sep 17 2020

...THE TORNADO WARNING FOR NORTHEASTERN CLARENDON AND EAST CENTRAL
SUMTER COUNTIES 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.

A Tornado Watch remains in effect until 600 PM EDT for central South
Carolina.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Columbia.

LAT...LON 3382 8002 3383 8011 3396 8017 3395 7998
      3391 7996
TIME...MOT...LOC 1711Z 186DEG 25KT 3395 8005 

$$

JAQ

The office that day

Everything else NWS Columbia, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 16, 11:22 PM EDT	River Flood Advisory	CAE	Lexington, Richland	46 hr
Sep 17, 7:56 AM EDT	Tornado Warning	CAE	Richland, Sumter	34 min
Sep 17, 8:09 AM EDT	Tornado Warning Tornado observed	CAE	Calhoun, Richland, Sumter	21 min
Sep 17, 8:30 AM EDT	Flash Flood Warning	CAE	Aiken, Edgefield, McCormick	3 hr
Sep 17, 9:22 AM EDT	Flash Flood Warning	CAE	Aiken, Barnwell, Edgefield, McCormick, Newberry, Saluda	3 hr
Sep 17, 9:33 AM EDT	Tornado Warning	CAE	Calhoun, Orangeburg	27 min
Sep 17, 9:46 AM EDT	River Flood Warning	CAE	Calhoun, Lexington, Richland	35 hr
Sep 17, 9:46 AM EDT	River Flood Warning	CAE	Calhoun, Richland	3 days
Sep 17, 9:46 AM EDT	River Flood Warning	CAE	Edgefield, McCormick	12 hr
Sep 17, 10:00 AM EDT	Tornado Warning	CAE	Calhoun, Clarendon, Orangeburg	45 min
Sep 17, 10:28 AM EDT	Flash Flood Warning	CAE	Bamberg, Calhoun, Clarendon, Orangeburg, Richland, Sumter	3 hr
Sep 17, 10:38 AM EDT	Flash Flood Warning	CAE	Aiken, Bamberg, Barnwell, Calhoun, Fairfield, Kershaw and 6 more	3 hr
Sep 17, 10:44 AM EDT	Tornado Warning	CAE	Clarendon, Sumter	46 min
Sep 17, 11:01 AM EDT	Tornado Warning	CAE	Clarendon, Sumter	29 min
Sep 17, 11:27 AM EDT	Tornado Warning	CAE	Lee, Sumter	48 min
Sep 17, 11:44 AM EDT	Tornado Warning	CAE	Calhoun, Clarendon, Orangeburg, Sumter	46 min
Sep 17, 12:06 PM EDT	Flash Flood Warning	CAE	Clarendon, Kershaw, Lee, Richland, Sumter	3 hr
Sep 17, 12:56 PM EDT	Tornado Warning	CAE	Calhoun, Clarendon, Orangeburg	36 min
Sep 17, 1:11 PM EDT	Tornado Warning	CAE	Sumter	49 min
Sep 17, 1:34 PM EDT	Flash Flood Warning	CAE	Calhoun, Clarendon, Orangeburg, Richland, Sumter	3 hr
Sep 17, 2:37 PM EDT	Severe Thunderstorm Warning	CAE	Lee, Sumter	23 min
Sep 17, 2:52 PM EDT	Severe Thunderstorm Warning	CAE	Clarendon	40 min
Sep 17, 3:02 PM EDT	Tornado Warning	CAE	Clarendon, Sumter	28 min
Sep 17, 3:19 PM EDT	Flash Flood Warning	CAE	Clarendon, Lee, Sumter	3 hr
Sep 17, 5:45 PM EDT	Areal Flood Advisory	CAE	Clarendon, Orangeburg, Sumter	60 min
Sep 17, 6:08 PM EDT	Special Weather Statement	CAE	Clarendon	22 min

Nearby

Tornado Warnings in South Carolina, 2020 Every tornado warning in 2020 Tornadoes in 2020

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.