Alert archive / South Carolina / Tornado Warnings in 2020

Tornado Warning 21, NWS Wilmington, NC

September 17, 2020Florence County, Marion County, South Carolina

NWS Wilmington, NC issued this tornado warning at Sep 17, 2020, 3:17 PM EDT for Florence County, Marion County, South Carolina. It was in force for 28 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, 3:17 PM EDT (19:17 UTC)
Expired: Sep 17, 2020, 3:45 PM EDT
In force: 28 min
Issued by: NWS Wilmington, NC
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

Counties Florence County, SC, Marion County, SC

The radar

The Wilmington radar (KLTX), 112 km from the middle of the area, began a volume at 19:17 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, 3:24 PM EDT	TORNADO	5 Ne Evergreen, SC	CORRECTED DATE!!! AN EF0 TORNADO WITH WINDS UP TO 75 MPH MOVED ALONG A 2 MILE PATH NEAR DIAMOND HEAD LOOP JUST SOUTH OF OLD RIVER ROAD. TREES AND LARGE LIMBS WERE BLOWN DOWN AND A METAL CARPORT WAS OVERTURNED.
Sep 17, 3:33 PM EDT	TSTM WND DMG	7 Ne Evergreen, SC	POWER LINES AND TREES BLOWN DOWN ACROSS BETHEL ROAD NEAR PAPER MILL ROAD. POSSIBLE TORNADO. TIME ESTIMATED.

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

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, 7.3 hours before the alert went out and 136 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.

355 
WFUS52 KILM 171917
TORILM
SCC041-067-171945-
/O.NEW.KILM.TO.W.0021.200917T1917Z-200917T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Wilmington NC
317 PM EDT Thu Sep 17 2020

The National Weather Service in Wilmington has issued a

* Tornado Warning for...
  Central Florence County in northeastern South Carolina...
  West central Marion County in northeastern South Carolina...

* Until 345 PM EDT.
    
* At 316 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Evergreen, or 8 miles southeast of Florence,
  moving northeast at 20 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...
  Claussen around 330 PM EDT.
  Francis Marion University and Mars Bluff around 335 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3399 7970 3409 7978 3427 7959 3409 7940
TIME...MOT...LOC 1916Z 233DEG 19KT 3408 7969 

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

$$

VAO

2 follow-up statements

078 
WWUS52 KILM 171927
SVSILM

Severe Weather Statement
National Weather Service Wilmington NC
327 PM EDT Thu Sep 17 2020

SCC041-067-171945-
/O.CON.KILM.TO.W.0021.000000T0000Z-200917T1945Z/
Florence SC-Marion SC-
327 PM EDT Thu Sep 17 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 345 PM EDT FOR NORTH
CENTRAL FLORENCE AND WEST CENTRAL MARION COUNTIES...
    
At 327 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Claussen, or 9 miles southeast of Florence, moving
northeast at 20 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...
  Francis Marion University around 335 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3405 7964 3413 7971 3426 7958 3422 7954
      3412 7943
TIME...MOT...LOC 1927Z 233DEG 19KT 3412 7963 

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

$$

VAO

449 
WWUS52 KILM 171945
SVSILM

Severe Weather Statement
National Weather Service Wilmington NC
345 PM EDT Thu Sep 17 2020

SCC041-067-171954-
/O.EXP.KILM.TO.W.0021.000000T0000Z-200917T1945Z/
Florence SC-Marion SC-
345 PM EDT Thu Sep 17 2020

...THE TORNADO WARNING FOR NORTH CENTRAL FLORENCE AND WEST CENTRAL
MARION COUNTIES WILL EXPIRE AT 345 PM EDT...
    
The Tornado Warning that was previously in effect has been reissued 
for NE Florence and NW Marion counties and is in effect until 
4:15PM. Please refer to that bulletin for the latest severe weather 
information.

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

Remember, a Tornado Warning still remains in effect for NE Florence 
and NW Marion counties and is in effect until 4:15PM.

LAT...LON 3405 7964 3413 7971 3426 7958 3422 7954
      3412 7943
TIME...MOT...LOC 1944Z 233DEG 19KT 3417 7955 

$$

VAO

The office that day

Everything else NWS Wilmington, NC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 17, 11:45 AM EDT	River Flood Warning	ILM	Darlington, Florence	5 days
Sep 17, 1:08 PM EDT	Flash Flood Warning	ILM	Darlington, Florence	3 hr
Sep 17, 1:38 PM EDT	Tornado Warning	ILM	Darlington, Florence	37 min
Sep 17, 1:46 PM EDT	Tornado Warning	ILM	Horry	29 min
Sep 17, 1:56 PM EDT	Areal Flood Advisory	ILM	Horry	41 min
Sep 17, 2:23 PM EDT	Areal Flood Advisory	ILM	Darlington, Florence, Marlboro	3 hr
Sep 17, 2:42 PM EDT	Severe Thunderstorm Warning	ILM	Darlington, Florence	33 min
Sep 17, 2:54 PM EDT	Flash Flood Warning	ILM	Darlington, Dillon, Florence, Marlboro	3 hr
Sep 17, 3:32 PM EDT	Areal Flood Advisory	ILM	Florence, Williamsburg	106 min
Sep 17, 3:44 PM EDT	Tornado Warning	ILM	Dillon, Florence, Marion	9 min
Sep 17, 4:00 PM EDT	Tornado Warning	ILM	Dillon, Marion	13 min
Sep 17, 4:14 PM EDT	Areal Flood Advisory	ILM	Dillon, Florence, Marion	109 min
Sep 17, 4:45 PM EDT	Special Weather Statement	ILM	Georgetown	30 min
Sep 17, 5:45 PM EDT	Areal Flood Advisory	ILM	Georgetown, Horry, Marion	2 hr
Sep 17, 6:41 PM EDT	Special Weather Statement	ILM	Horry	34 min
Sep 17, 6:51 PM EDT	Tornado Warning	ILM	Horry	24 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.