Alert archive / South Carolina / Tornado Warnings in 2020

Tornado Warning 18, NWS Columbia, SC

September 17, 2020Calhoun County, Richland County, Sumter County, South Carolina

NWS Columbia, SC issued this tornado warning at Sep 17, 2020, 8:09 AM EDT for Calhoun County, Richland County, Sumter County, South Carolina. It was in force for 21 min. 2 reports 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: Sep 17, 2020, 8:09 AM EDT (12:09 UTC)
Expired: Sep 17, 2020, 8:30 AM EDT
In force: 21 min
Issued by: NWS Columbia, SC
Area: Storm-based polygon
Tornado: Observed
Hail: 0.0 in

Counties Calhoun County, SC, Richland County, SC, Sumter County, SC

The radar

The Columbia radar (KCAE), 43 km from the middle of the area, began a volume at 12:12 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

Time	Report	Where	Remark
Sep 17, 8:12 AM EDT	TORNADO	8 Sse Eastover, SC	CORRECTS PREVIOUS TORNADO REPORT FROM 8 SSE EASTOVER. RADAR CONFIRMED DEBRIS BALL.
Sep 17, 8:12 AM EDT	TORNADO	8 Sse Eastover, SC	RADAR CONFIRMED DEBRIS BALL.

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

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 0.2 hours before the alert went out and 119 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.

929 
WFUS52 KCAE 171209
TORCAE
SCC017-079-085-171245-
/O.NEW.KCAE.TO.W.0018.200917T1209Z-200917T1245Z/

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

The National Weather Service in Columbia has issued a

* Tornado Warning for...
  East central Calhoun County in central South Carolina...
  Southwestern Sumter County in central South Carolina...
  Southeastern Richland County in central South Carolina...

* Until 845 AM EDT.
    
* At 809 AM EDT, a tornado producing storm was located near Poinsett
  State Park, or 14 miles southeast of McEntire Air Base, moving
  northwest at 15 mph.

  HAZARD...Damaging tornado.

  SOURCE...Radar confirmed tornado.

  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 tornadic storm will be near...
  McEntire Air Base, Eastover and Gadsden around 845 AM EDT.

Other locations impacted by this tornadic thunderstorm include Fort
Motte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. Immediately move to an interior room on the lowest floor of
a sturdy building.

&&

LAT...LON 3372 8061 3370 8065 3390 8089 3398 8070
TIME...MOT...LOC 1209Z 156DEG 14KT 3375 8064 

TORNADO...OBSERVED
HAIL...0.00IN

$$

JAQ

2 follow-up statements

453 
WWUS52 KCAE 171224
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
824 AM EDT Thu Sep 17 2020

SCC017-085-171233-
/O.CAN.KCAE.TO.W.0018.000000T0000Z-200917T1245Z/
Calhoun SC-Sumter SC-
824 AM EDT Thu Sep 17 2020

...THE TORNADO WARNING FOR EAST CENTRAL CALHOUN AND SOUTHWESTERN
SUMTER COUNTIES IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

LAT...LON 3381 8066 3377 8072 3390 8089 3398 8070
TIME...MOT...LOC 1223Z 143DEG 22KT 3383 8072 

$$

SCC079-171245-
/O.CON.KCAE.TO.W.0018.000000T0000Z-200917T1245Z/
Richland SC-
824 AM EDT Thu Sep 17 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 AM EDT FOR
SOUTHEASTERN RICHLAND COUNTY...
    
At 823 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Gadsden, or 7 miles southeast of McEntire Air Base,
moving northwest 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...
  McEntire Air Base and Hopkins around 845 AM EDT.

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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. Immediately move to an interior room on the lowest floor of
a sturdy building.

&&

LAT...LON 3381 8066 3377 8072 3390 8089 3398 8070
TIME...MOT...LOC 1223Z 143DEG 22KT 3383 8072 

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

$$

JAQ

682 
WWUS52 KCAE 171230
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
830 AM EDT Thu Sep 17 2020

SCC079-171240-
/O.CAN.KCAE.TO.W.0018.000000T0000Z-200917T1245Z/
Richland SC-
830 AM EDT Thu Sep 17 2020

...THE TORNADO WARNING FOR SOUTHEASTERN RICHLAND COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.  However heavy rain is
still possible with this thunderstorm.

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

LAT...LON 3381 8066 3377 8072 3390 8089 3398 8070
TIME...MOT...LOC 1229Z 156DEG 14KT 3386 8073 

$$

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, 8:30 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, 12:39 PM EDT	Tornado Warning	CAE	Clarendon, Sumter	33 min
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.