Alert archive / South Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 5, NWS Columbia, SC

August 22, 2021Lexington County, South Carolina

NWS Columbia, SC issued this flash flood warning at Aug 22, 2021, 1:46 PM EDT for Lexington County, South Carolina. It was in force for 119 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: Aug 22, 2021, 1:46 PM EDT (17:46 UTC)
Expired: Aug 22, 2021, 3:45 PM EDT
In force: 119 min
Issued by: NWS Columbia, SC
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Lexington County, SC

The radar

The Columbia radar (KCAE), 5 km from the middle of the area, began a volume at 17:47 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 22, 2:25 PM EDT	FLASH FLOOD	1 Wsw Cayce, SC	SPOTTER POSTED VIDEO ON SOCIAL MEDIA OF FLOODED ROADWAY WITH A STRANDED VEHICLE UNDER WATER. TIME BASED ON TIME OF TWEET.

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, 5.8 hours before the alert went out and 161 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.

133 
WGUS52 KCAE 221746
FFWCAE
SCC063-221945-
/O.NEW.KCAE.FF.W.0005.210822T1746Z-210822T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Columbia has issued a

* Flash Flood Warning for...
  East Central Lexington County in central South Carolina...

* Until 345 PM EDT.

* At 146 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 3 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 2 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.

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

* Some locations that will experience flash flooding include...
  Lexington, West Columbia, Cayce, Springdale, Oak Grove, Red Bank, 
  South Congaree, Pine Ridge, Columbia Metro Airport, Guignard Park 
  and Barr Lake.

This includes the following highways...
	Interstate 20 in South Carolina between mile markers 54 and 58.
	Interstate 77 between mile markers 0 and 1.
	Interstate 26 between mile markers 111 and 115.

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 3399 8121 3399 8105 3393 8104 3392 8116
      3395 8128 3399 8127

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

$$

CAL

1 follow-up statement

660 
WGUS72 KCAE 221833
FFSCAE

Flash Flood Statement
National Weather Service Columbia SC
233 PM EDT Sun Aug 22 2021

SCC063-221945-
/O.CON.KCAE.FF.W.0005.000000T0000Z-210822T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lexington SC-
233 PM EDT Sun Aug 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM EDT THIS 
AFTERNOON FOR EAST CENTRAL LEXINGTON COUNTY...

At 233 PM EDT, Doppler radar continues to indicate thunderstorms 
producing heavy rain across much of the warned area. Between 2 and 3 
inches of rain have fallen. Additional rainfall amounts of 1 to 2 
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.

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

Some locations that will experience flash flooding include...
  Lexington, West Columbia, Cayce, Springdale, Oak Grove, Red Bank, 
  South Congaree, Pine Ridge, Columbia Metro Airport, Guignard Park 
  and Barr Lake.

This includes the following highways...
	Interstate 20 in South Carolina between mile markers 54 and 58.
	Interstate 77 between mile markers 0 and 1.
	Interstate 26 between mile markers 111 and 115.

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 3399 8121 3399 8105 3393 8104 3392 8116
      3395 8128 3399 8127

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

$$

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, 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, 3:39 PM EDT	Flash Flood Warning Considerable damage threat	CAE	Aiken, Calhoun, Lexington, Orangeburg, Richland	111 min
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.