Alert archive / South Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Wilmington, NC

August 3, 20214 counties in South Carolina

NWS Wilmington, NC issued this flash flood warning at Aug 3, 2021, 12:55 PM EDT for 4 counties in South Carolina. It was in force for 3 hr. 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 3, 2021, 12:55 PM EDT (16:55 UTC)
Expired: Aug 3, 2021, 4:00 PM EDT
In force: 3 hr
Issued by: NWS Wilmington, NC
Area: Storm-based polygon
Flood severity: None

Counties Darlington County, SC, Dillon County, SC, Florence County, SC, Marion County, SC

The radar

The Wilmington radar (KLTX), 124 km from the middle of the area, began a volume at 16:56 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 3, 1:50 PM EDT	FLASH FLOOD	Marion, SC	NUMEROUS STREETS FLOODED ACROSS TOWN.

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, 4.9 hours before the alert went out and 134 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: 185 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 1002 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

681 
WGUS52 KILM 031655
FFWILM
SCC031-033-041-067-032000-
/O.NEW.KILM.FF.W.0002.210803T1655Z-210803T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Wilmington NC
1255 PM EDT Tue Aug 3 2021

The National Weather Service in Wilmington has issued a

* Flash Flood Warning for...
  Southeastern Darlington County in northeastern South Carolina...
  Southwestern Dillon County in northeastern South Carolina...
  Florence County in northeastern South Carolina...
  Northwestern Marion County in northeastern South Carolina...

* Until 400 PM EDT.

* At 1255 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 3.5 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...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Florence, Marion, Lake City, Darlington, Mullins, Timmonsville, 
  Latta, Pamplico, Quinby, Sellers, Claussen, Francis Marion 
  University, Mars Bluff, Evergreen, Effingham, Hyman, New Hope, 
  Friendfield, Blue Brick and Florence Darlington Technical College 
  Main Campus.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause dangerous flooding, 
especially near creeks and streams, drainage ditches, and low-lying 
flood prone areas. Turn around, don't drown if you encounter a 
flooded road. Most flood deaths occur in vehicles. Stay away from 
storm drains, culverts, creeks, and streams. Water levels can rise 
rapidly and sweep you away.

&&

LAT...LON 3407 8003 3425 7998 3434 7968 3431 7966
      3430 7963 3436 7960 3438 7951 3435 7927
      3416 7926 3383 7975 3384 7980 3388 7984
      3389 7985 3388 7987 3389 7995 3395 7997
      3399 7989 3401 7991 3404 7999

FLASH FLOOD...RADAR INDICATED

$$

MW

1 follow-up statement

071 
WGUS72 KILM 031846
FFSILM

Flash Flood Statement
National Weather Service Wilmington NC
246 PM EDT Tue Aug 3 2021

SCC031-033-041-067-032000-
/O.CON.KILM.FF.W.0002.000000T0000Z-210803T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Darlington SC-Dillon SC-Florence SC-Marion SC-
246 PM EDT Tue Aug 3 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 4 PM EDT THIS 
AFTERNOON FOR EAST CENTRAL DARLINGTON, SOUTHWESTERN DILLON, FLORENCE 
AND NORTHWESTERN MARION COUNTIES...

At 246 PM EDT, Local law enforcement reported flooding from heavy 
rain across the warned area. Between 2 and 5 inches of rain have 
fallen. Additional rainfall amounts up to 1 inch are possible in the 
warned area. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Law enforcement reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Florence, Marion, Lake City, Mullins, Latta, Pamplico, Quinby, 
  Sellers, Claussen, Evergreen, Francis Marion University, Mars 
  Bluff, Hyman, Effingham, Friendfield, Blue Brick, New Hope, 
  Florence Darlington Technical College Main Campus, Zion and 
  Floydale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause dangerous flooding, 
especially near creeks and streams, drainage ditches, and low-lying 
flood prone areas. Turn around, don't drown if you encounter a 
flooded road. Most flood deaths occur in vehicles. Stay away from 
storm drains, culverts, creeks, and streams. Water levels can rise 
rapidly and sweep you away.

&&

LAT...LON 3426 7989 3434 7968 3431 7966 3430 7963
      3433 7947 3435 7927 3416 7926 3383 7974
      3384 7980 3388 7984 3389 7985 3388 7987
      3389 7995 3395 7997 3399 7989 3401 7991
      3407 7993

FLASH FLOOD...OBSERVED

$$

MW

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 3, 3:20 AM EDT	Flash Flood Watch	ILM	Florence, Georgetown, Horry, Marion, Williamsburg	4 min
Aug 3, 3:30 AM EDT	Flash Flood Watch	ILM	Georgetown, Horry, Williamsburg	24 hr
Aug 3, 11:38 AM EDT	Areal Flood Advisory	ILM	Florence, Marion	85 min
Aug 3, 12:01 PM EDT	Areal Flood Advisory	ILM	Georgetown, Horry	103 min
Aug 3, 1:12 PM EDT	Flash Flood Warning	ILM	Horry	2 hr
Aug 3, 4:00 PM EDT	Flash Flood Warning	ILM	Dillon, Marion	56 min
Aug 3, 4:04 PM EDT	Areal Flood Advisory	ILM	Horry	86 min
Aug 3, 5:33 PM EDT	Areal Flood Advisory	ILM	Horry	81 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.