Alert archive / South Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 4, NWS Wilmington, NC

August 3, 2021Dillon County, Marion County, South Carolina

NWS Wilmington, NC issued this flash flood warning at Aug 3, 2021, 4:00 PM EDT for Dillon County, Marion County, South Carolina. It was in force for 56 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 3, 2021, 4:00 PM EDT (20:00 UTC)
Expired: Aug 3, 2021, 4:56 PM EDT
In force: 56 min
Issued by: NWS Wilmington, NC
Area: Storm-based polygon
Flood severity: None

Counties Dillon County, SC, Marion County, SC

The radar

The Wilmington radar (KLTX), 96 km from the middle of the area, began a volume at 20:03 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, 8.0 hours before the alert went out and 148 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.

714 
WGUS52 KILM 032000
FFWILM
SCC033-067-032300-
/O.NEW.KILM.FF.W.0004.210803T2000Z-210803T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Wilmington has issued a

* Flash Flood Warning for...
  South Central Dillon County in northeastern South Carolina...
  Northern Marion County in northeastern South Carolina...

* Until 700 PM EDT.

* At 400 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across 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...
  Marion, Mullins, Sellers, Zion, Rains, Smithboro, Gapway, Fork, 
  Blue Brick and Carolinas Hospital System - Marion.

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 3425 7955 3430 7943 3428 7914 3411 7923
      3409 7925 3405 7952 3406 7952 3410 7953
      3410 7952 3410 7951 3412 7952 3413 7952
      3413 7953

FLASH FLOOD...RADAR INDICATED

$$

MBB

1 follow-up statement

675 
WGUS72 KILM 032056
FFSILM

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

SCC033-067-032106-
/O.CAN.KILM.FF.W.0004.000000T0000Z-210803T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dillon SC-Marion SC-
456 PM EDT Tue Aug 3 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTH CENTRAL DILLON AND 
NORTHERN MARION COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1100 AM EDT Wednesday 
for portions of southeast North Carolina and northeast South 
Carolina.

LAT...LON 3425 7955 3430 7943 3428 7914 3411 7923
      3409 7925 3405 7952 3406 7952 3410 7953
      3410 7952 3410 7951 3412 7952 3413 7952
      3413 7953

$$

MBB

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, 12:55 PM EDT	Flash Flood Warning	ILM	Darlington, Dillon, Florence, Marion	3 hr
Aug 3, 1:12 PM EDT	Flash Flood Warning	ILM	Horry	2 hr
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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.