Alert archive / South Carolina / Tornado Warnings in 2017

Tornado Warning 13, NWS Wilmington, NC

August 31, 2017Horry County, Marion County, South Carolina

NWS Wilmington, NC issued this tornado warning at Aug 31, 2017, 7:47 PM EDT for Horry 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: Aug 31, 2017, 7:47 PM EDT (23:47 UTC)
Expired: Aug 31, 2017, 8:15 PM EDT
In force: 28 min
Issued by: NWS Wilmington, NC
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Horry County, SC, Marion County, SC

The radar

The Wilmington radar (KLTX), 81 km from the middle of the area, began a volume at 23:47 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
Aug 31, 7:48 PM EDT	TSTM WND DMG	Brittons Neck, SC	TREE DOWN ON HIGHWAY 378 IN THE BRITTONS NECK AREA. TIME ESTIMATED BY RADAR.
Aug 31, 7:54 PM EDT	TSTM WND DMG	10 W Conway, SC	TREE DOWN IN ROAD US378 AND PEE DEE HWY

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, 11.8 hours before the alert went out and 123 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: 331 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 812 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 69 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

As transmitted.

190 
WFUS52 KILM 312347
TORILM
SCC051-067-010015-
/O.NEW.KILM.TO.W.0013.170831T2347Z-170901T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Wilmington NC
747 PM EDT THU AUG 31 2017

The National Weather Service in Wilmington has issued a

* Tornado Warning for...
  Southwestern Horry County in northeastern South Carolina...
  South central Marion County in northeastern South Carolina...

* Until 815 PM EDT
    
* At 747 PM EDT, a severe thunderstorm capable of producing a tornado
  was located near Pee Dee Crossroads, or 14 miles west of Conway,
  moving east at 25 mph.

  HAZARD...Tornado. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Expect damage to mobile homes, roofs, and vehicles. 

* Locations impacted include...
  Conway, Red Hill, Horry, Hickory Grove, Homewood, Horry Georgetown
  Technical College Conway Campus, Adrian, Pee Dee Crossroads,
  Nixonville, Dongola, Coastal Carolina University, Brittons Neck,
  Forestbrook, Lighthouse Care Center Of Conway and Conway Medical
  Center.

This includes the following highways...
 SC Highway 31 between mile markers 5 and 9.
 SC Highway 22 between mile markers 1 and 17.

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.

&&

LAT...LON 3375 7929 3380 7933 3381 7931 3383 7932
      3383 7933 3384 7934 3384 7937 3387 7939
      3388 7941 3389 7940 3390 7941 3400 7890
      3373 7886 3372 7929
TIME...MOT...LOC 2347Z 262DEG 21KT 3383 7931 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

SHK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 4:27 PM EDT	Special Weather Statement	ILM	Horry	48 min
Aug 31, 5:13 PM EDT	Severe Thunderstorm Warning	ILM	Darlington	62 min
Aug 31, 5:17 PM EDT	Special Weather Statement	ILM	Horry	43 min
Aug 31, 6:03 PM EDT	Special Weather Statement	ILM	Marlboro	57 min
Aug 31, 6:15 PM EDT	Special Weather Statement	ILM	Dillon	60 min
Aug 31, 7:25 PM EDT	Special Weather Statement	ILM	Horry	65 min

Nearby

Tornado Warnings in South Carolina, 2017 Every tornado warning in 2017 Tornadoes 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.