Alert archive / South Carolina / Flash Flood Warnings in 2020

Flash Flood Warning 13, NWS Columbia, SC

September 17, 20206 counties in South Carolina; Burke County, Richmond County, Georgia

NWS Columbia, SC issued this flash flood warning at Sep 17, 2020, 9:22 AM EDT for 6 counties in South Carolina; Burke County, Richmond County, Georgia. It was in force for 3 hr. 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, 9:22 AM EDT (13:22 UTC)
Expired: Sep 17, 2020, 12:30 PM EDT
In force: 3 hr
Issued by: NWS Columbia, SC
Area: Storm-based polygon
Flood severity: None

Counties Burke County, GA, Richmond County, GA, Aiken County, SC, Barnwell County, SC, Edgefield County, SC, McCormick County, SC, Newberry County, SC, Saluda County, SC

The radar

The Columbia radar (KCAE), 71 km from the middle of the area, began a volume at 13:26 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, 9:46 AM EDT	FLASH FLOOD	2 Ene Augusta, GA	LANEY WALKER BLVD - VEHICLE FLOATING.
Sep 17, 10:24 AM EDT	FLASH FLOOD	4 Nne Gloverville, SC	FLOODING ON CANAL STREET AND DRAINAGE DITCHES ON TROLLEY LINE ROAD.

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, 1.4 hours before the alert went out and 184 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.

099 
WGUS52 KCAE 171322
FFWCAE
GAC033-245-SCC003-011-037-065-071-081-171630-
/O.NEW.KCAE.FF.W.0013.200917T1322Z-200917T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Columbia SC
922 AM EDT Thu Sep 17 2020

The National Weather Service in Columbia has issued a

* Flash Flood Warning for...
  Eastern Burke County in east central Georgia...
  Eastern Richmond County in east central Georgia...
  Aiken County in central South Carolina...
  Western Barnwell County in central South Carolina...
  Edgefield County in central South Carolina...
  Southeastern McCormick County in central South Carolina...
  Southwestern Newberry County in central South Carolina...
  Saluda County in central South Carolina...

* Until 1230 PM EDT.

* At 922 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Aiken, North Augusta, Barnwell, Aiken Mall, Clearwater, Belvedere, 
  Augusta, Savannah River Site, Plant Vogtle, Edgefield, Saluda, 
  Williston, Johnston, New Ellenton, Jackson, Sardis, Ridge Spring, 
  USC Aiken and Graniteville.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3398 8213 3398 8205 3395 8205 3396 8201
      3413 8187 3420 8194 3430 8190 3435 8180
      3389 8158 3320 8137 3313 8143 3316 8154
      3310 8161 3305 8155 3305 8154 3291 8177
      3294 8181

FLASH FLOOD...RADAR INDICATED

$$

CAL

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 16, 11:22 PM EDT	River Flood Advisory	CAE	Lexington, Richland	46 hr
Sep 17, 7:56 AM EDT	Tornado Warning	CAE	Richland, Sumter	34 min
Sep 17, 8:09 AM EDT	Tornado Warning Tornado observed	CAE	Calhoun, Richland, Sumter	21 min
Sep 17, 8:30 AM EDT	Flash Flood Warning	CAE	Aiken, Edgefield, McCormick	3 hr
Sep 17, 9:33 AM EDT	Tornado Warning	CAE	Calhoun, Orangeburg	27 min
Sep 17, 9:46 AM EDT	River Flood Warning	CAE	Calhoun, Lexington, Richland	35 hr
Sep 17, 9:46 AM EDT	River Flood Warning	CAE	Calhoun, Richland	3 days
Sep 17, 9:46 AM EDT	River Flood Warning	CAE	Edgefield, McCormick	12 hr
Sep 17, 10:00 AM EDT	Tornado Warning	CAE	Calhoun, Clarendon, Orangeburg	45 min
Sep 17, 10:28 AM EDT	Flash Flood Warning	CAE	Bamberg, Calhoun, Clarendon, Orangeburg, Richland, Sumter	3 hr
Sep 17, 10:38 AM EDT	Flash Flood Warning	CAE	Aiken, Bamberg, Barnwell, Calhoun, Fairfield, Kershaw and 6 more	3 hr
Sep 17, 10:44 AM EDT	Tornado Warning	CAE	Clarendon, Sumter	46 min
Sep 17, 11:01 AM EDT	Tornado Warning	CAE	Clarendon, Sumter	29 min
Sep 17, 11:27 AM EDT	Tornado Warning	CAE	Lee, Sumter	48 min
Sep 17, 11:44 AM EDT	Tornado Warning	CAE	Calhoun, Clarendon, Orangeburg, Sumter	46 min
Sep 17, 12:06 PM EDT	Flash Flood Warning	CAE	Clarendon, Kershaw, Lee, Richland, Sumter	3 hr
Sep 17, 12:39 PM EDT	Tornado Warning	CAE	Clarendon, Sumter	33 min
Sep 17, 12:56 PM EDT	Tornado Warning	CAE	Calhoun, Clarendon, Orangeburg	36 min
Sep 17, 1:11 PM EDT	Tornado Warning	CAE	Sumter	49 min
Sep 17, 1:34 PM EDT	Flash Flood Warning	CAE	Calhoun, Clarendon, Orangeburg, Richland, Sumter	3 hr
Sep 17, 2:37 PM EDT	Severe Thunderstorm Warning	CAE	Lee, Sumter	23 min
Sep 17, 2:52 PM EDT	Severe Thunderstorm Warning	CAE	Clarendon	40 min
Sep 17, 3:02 PM EDT	Tornado Warning	CAE	Clarendon, Sumter	28 min
Sep 17, 3:19 PM EDT	Flash Flood Warning	CAE	Clarendon, Lee, Sumter	3 hr
Sep 17, 5:45 PM EDT	Areal Flood Advisory	CAE	Clarendon, Orangeburg, Sumter	60 min
Sep 17, 6:08 PM EDT	Special Weather Statement	CAE	Clarendon	22 min

Nearby

Flash Flood Warnings in South Carolina, 2020 Flash Flood Warnings in Georgia, 2020 Every flash flood warning 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.