Alert archive / South Carolina / Flash Flood Warnings in 2018

Flash Flood Warning 12, NWS Columbia, SC

September 16, 2018Chesterfield County, South Carolina

NWS Columbia, SC issued this flash flood warning at Sep 16, 2018, 7:34 PM EDT for Chesterfield County, South Carolina. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 16, 2018, 7:34 PM EDT (23:34 UTC)
Expired
Sep 17, 2018, 1:30 AM EDT
In force
6 hr
Issued by
NWS Columbia, SC
Area
Storm-based polygon
Emergency
Flash flood emergency
Flood severity
None

County Chesterfield County, SC

The radar

The Columbia radar (KCAE), 117 km from the middle of the area, began a volume at 23:37 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.6 hours before the alert went out and 162 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2018-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2018-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 238 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
6 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
658 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
238 m²/s²
0-3 km storm-relative helicity
367 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 15, 8:27 PM EDTSpecial Weather StatementCAEChesterfield, Fairfield, Kershaw, Lancaster, Newberry93 min
Sep 15, 9:12 PM EDTAreal Flood AdvisoryCAEChesterfield11 hr
Sep 15, 10:40 PM EDTSpecial Weather StatementCAEChesterfield, Lancaster95 min
Sep 16, 3:35 AM EDTSpecial Weather StatementCAEChesterfield, Lancaster55 min
Sep 16, 4:44 AM EDTSpecial Weather StatementCAEChesterfield2 hr
Sep 16, 5:37 AM EDTFlash Flood WarningCAEChesterfield3 hr
Sep 16, 8:28 AM EDTFlash Flood WarningCAEChesterfield, Kershaw, Lancaster6 hr
Sep 16, 8:44 AM EDTSpecial Weather StatementCAEChesterfield46 min
Sep 16, 2:00 PM EDTSpecial Weather StatementCAEChesterfield45 min
Sep 16, 2:11 PM EDTFlash Flood Warning EmergencyCAEChesterfield, Lancaster6 hr
Sep 16, 6:29 PM EDTSpecial Weather StatementCAEMarlboro31 min
Sep 16, 7:50 PM EDTAreal Flood WarningCAEChesterfield, Kershaw, Lancaster6 hr

Nearby

Flash Flood Warnings in South Carolina, 2018Every flash flood warning in 2018

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.