Alert archive / South Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 6, NWS Columbia, SC

August 22, 20215 counties in South Carolina

NWS Columbia, SC issued this flash flood warning at Aug 22, 2021, 3:39 PM EDT for 5 counties in South Carolina. It was in force for 111 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: Aug 22, 2021, 3:39 PM EDT (19:39 UTC)
Expired: Aug 22, 2021, 5:30 PM EDT
In force: 111 min
Issued by: NWS Columbia, SC
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Aiken County, SC, Calhoun County, SC, Lexington County, SC, Orangeburg County, SC, Richland County, SC

The radar

The Columbia radar (KCAE), 31 km from the middle of the area, began a volume at 19:40 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 nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 7.7 hours before the alert went out and 131 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: 890 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 704 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 92 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

As transmitted.

069 
WGUS52 KCAE 221939
FFWCAE
SCC003-017-063-075-079-222130-
/O.NEW.KCAE.FF.W.0006.210822T1939Z-210822T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Columbia SC
339 PM EDT Sun Aug 22 2021

The National Weather Service in Columbia has issued a

* Flash Flood Warning for...
  Eastern Aiken County in central South Carolina...
  Calhoun County in central South Carolina...
  Southeastern Lexington County in central South Carolina...
  Northwestern Orangeburg County in central South Carolina...
  Southeastern Richland County in central South Carolina...

* Until 530 PM EDT.

* At 339 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 3.5 inches of rain have fallen. Additional rainfall amounts 
  of 1 to 3 inches are possible in the warned area. Flash flooding 
  is ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar and automated gauges.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Orangeburg, Brookdale, St. Matthews, Gaston, Sandy Run, Swansea, 
  North, Springfield, Cameron, Salley, Neeses, Woodford, Livingston, 
  Prince of Orange Mall, Fort Motte and Creston.

This includes the following highways...
	Interstate 26 between mile markers 124 and 148.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Most flooding deaths occur in vehicles. Never drive through a 
flooded roadway or around barricades. Turn around, don't drown.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3353 8133 3370 8122 3382 8115 3383 8101
      3382 8092 3380 8066 3354 8056 3350 8134

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

CAL

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 1:21 AM EDT	Areal Flood Advisory	CAE	Bamberg, Barnwell, Orangeburg	114 min
Aug 22, 11:10 AM EDT	Areal Flood Advisory	CAE	Calhoun, Lexington, Richland	110 min
Aug 22, 12:40 PM EDT	Areal Flood Advisory	CAE	Richland	2 hr
Aug 22, 1:27 PM EDT	Areal Flood Advisory	CAE	Fairfield, Kershaw	2 hr
Aug 22, 1:32 PM EDT	Areal Flood Advisory	CAE	Lexington, Newberry, Richland	118 min
Aug 22, 1:46 PM EDT	Flash Flood Warning Considerable damage threat	CAE	Lexington	119 min
Aug 22, 2:18 PM EDT	Areal Flood Advisory	CAE	Saluda	117 min
Aug 22, 2:41 PM EDT	Areal Flood Advisory	CAE	Calhoun, Lexington, Orangeburg, Richland	3 hr
Aug 22, 4:55 PM EDT	Areal Flood Advisory	CAE	Bamberg, Barnwell, Calhoun, Clarendon, Orangeburg	103 min

Nearby

Flash Flood Warnings in South Carolina, 2021 Every flash flood warning in 2021

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.