Alert archive / South Carolina / Tornado Warnings in 2020

Tornado Warning 20, NWS Columbia, SC

September 17, 2020Calhoun County, Clarendon County, Orangeburg County, South Carolina

NWS Columbia, SC issued this tornado warning at Sep 17, 2020, 10:00 AM EDT for Calhoun County, Clarendon County, Orangeburg County, South Carolina. It was in force for 45 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
Sep 17, 2020, 10:00 AM EDT (14:00 UTC)
Expired
Sep 17, 2020, 10:45 AM EDT
In force
45 min
Issued by
NWS Columbia, SC
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.0 in

Counties Calhoun County, SC, Clarendon County, SC, Orangeburg County, SC

The radar

The Columbia radar (KCAE), 75 km from the middle of the area, began a volume at 14:02 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
Sep 17, 10:17 AM EDTTORNADO4 Ne Santee, SCA NATIONAL WEATHER SERVICE STORM SURVEY TEAM CONFIRMED AN EF-0 TORNADO, WITH PEAK WIND SPEEDS OF 85 MPH, NORTHEAST OF SANTEE IN CLARENDON COUNTY, SC. THE TORNADO BEGAN ALONG THE EDGE OF LAKE MARION, JUST WEST OF I-95, NEAR THE ADAMS LANDING COMMUNITY. THE TORN

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, 2.0 hours before the alert went out and 90 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, Charleston AFB, SC at 12:00Z on 2020-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1154 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 12:00Z on 2020-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 188 square meters per square second.193958Sfc1 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
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.

521 
WFUS52 KCAE 171400
TORCAE
SCC017-027-075-171445-
/O.NEW.KCAE.TO.W.0020.200917T1400Z-200917T1445Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Columbia SC
1000 AM EDT Thu Sep 17 2020

The National Weather Service in Columbia has issued a

* Tornado Warning for...
  Southeastern Calhoun County in central South Carolina...
  Southwestern Clarendon County in central South Carolina...
  East central Orangeburg County in central South Carolina...

* Until 1045 AM EDT.
    
* At 959 AM EDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles south of Santee State Park, or 15 miles north
  of Indian Field, 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...
  Santee State Park around 1015 AM EDT.
  Summerton around 1035 AM EDT.

Other locations impacted by this tornadic thunderstorm include
Santee, Davis Station, Mill Creek Marina and Campground, Vance and
St. Paul.

This includes Interstate 95 between mile markers 94 and 116.
 
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 3365 8019 3339 8041 3343 8053 3371 8047
      3371 8045 3372 8045 3372 8043 3371 8043
      3371 8041
TIME...MOT...LOC 1359Z 198DEG 20KT 3344 8046 

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

$$

JAQ
1 follow-up statement
035 
WWUS52 KCAE 171426
SVSCAE

Severe Weather Statement
National Weather Service Columbia SC
1026 AM EDT Thu Sep 17 2020

SCC017-075-171435-
/O.CAN.KCAE.TO.W.0020.000000T0000Z-200917T1445Z/
Calhoun SC-Orangeburg SC-
1026 AM EDT Thu Sep 17 2020

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

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

LAT...LON 3367 8025 3353 8039 3356 8048 3371 8047
      3371 8045 3372 8045 3372 8043 3371 8043
      3371 8041
TIME...MOT...LOC 1425Z 198DEG 20KT 3358 8040 

$$

SCC027-171445-
/O.CON.KCAE.TO.W.0020.000000T0000Z-200917T1445Z/
Clarendon SC-
1026 AM EDT Thu Sep 17 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1045 AM EDT FOR
SOUTHWESTERN CLARENDON COUNTY...
    
At 1025 AM EDT, a severe thunderstorm capable of producing a tornado
was located near Summerton, or 13 miles southwest 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...
  Summerton around 1035 AM EDT.

Other locations impacted by this tornadic thunderstorm include St.
Paul.

This includes Interstate 95 between mile markers 104 and 116.
 
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 3367 8025 3353 8039 3356 8048 3371 8047
      3371 8045 3372 8045 3372 8043 3371 8043
      3371 8041
TIME...MOT...LOC 1425Z 198DEG 20KT 3358 8040 

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

$$

JAQ

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 11:22 PM EDTRiver Flood AdvisoryCAELexington, Richland46 hr
Sep 17, 7:56 AM EDTTornado WarningCAERichland, Sumter34 min
Sep 17, 8:09 AM EDTTornado Warning Tornado observedCAECalhoun, Richland, Sumter21 min
Sep 17, 8:30 AM EDTFlash Flood WarningCAEAiken, Edgefield, McCormick3 hr
Sep 17, 9:22 AM EDTFlash Flood WarningCAEAiken, Barnwell, Edgefield, McCormick, Newberry, Saluda3 hr
Sep 17, 9:33 AM EDTTornado WarningCAECalhoun, Orangeburg27 min
Sep 17, 9:46 AM EDTRiver Flood WarningCAECalhoun, Lexington, Richland35 hr
Sep 17, 9:46 AM EDTRiver Flood WarningCAECalhoun, Richland3 days
Sep 17, 9:46 AM EDTRiver Flood WarningCAEEdgefield, McCormick12 hr
Sep 17, 10:28 AM EDTFlash Flood WarningCAEBamberg, Calhoun, Clarendon, Orangeburg, Richland, Sumter3 hr
Sep 17, 10:38 AM EDTFlash Flood WarningCAEAiken, Bamberg, Barnwell, Calhoun, Fairfield, Kershaw and 6 more3 hr
Sep 17, 10:44 AM EDTTornado WarningCAEClarendon, Sumter46 min
Sep 17, 11:01 AM EDTTornado WarningCAEClarendon, Sumter29 min
Sep 17, 11:27 AM EDTTornado WarningCAELee, Sumter48 min
Sep 17, 11:44 AM EDTTornado WarningCAECalhoun, Clarendon, Orangeburg, Sumter46 min
Sep 17, 12:06 PM EDTFlash Flood WarningCAEClarendon, Kershaw, Lee, Richland, Sumter3 hr
Sep 17, 12:39 PM EDTTornado WarningCAEClarendon, Sumter33 min
Sep 17, 12:56 PM EDTTornado WarningCAECalhoun, Clarendon, Orangeburg36 min
Sep 17, 1:11 PM EDTTornado WarningCAESumter49 min
Sep 17, 1:34 PM EDTFlash Flood WarningCAECalhoun, Clarendon, Orangeburg, Richland, Sumter3 hr
Sep 17, 2:37 PM EDTSevere Thunderstorm WarningCAELee, Sumter23 min
Sep 17, 2:52 PM EDTSevere Thunderstorm WarningCAEClarendon40 min
Sep 17, 3:02 PM EDTTornado WarningCAEClarendon, Sumter28 min
Sep 17, 3:19 PM EDTFlash Flood WarningCAEClarendon, Lee, Sumter3 hr
Sep 17, 5:45 PM EDTAreal Flood AdvisoryCAEClarendon, Orangeburg, Sumter60 min
Sep 17, 6:08 PM EDTSpecial Weather StatementCAEClarendon22 min

Nearby

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