Alert archive / South Carolina / Flash Flood Watches in 2018

Flash Flood Watch 3, NWS Columbia, SC

September 13, 201811 counties in South Carolina

NWS Columbia, SC issued this flash flood watch at Sep 13, 2018, 3:30 PM EDT for 11 counties in South Carolina. It took effect at Sep 14, 2018, 12:00 PM EDT. It was in force for 65 hr.

The area

The counties it named.

The facts

Issued
Sep 13, 2018, 3:30 PM EDT (19:30 UTC)
In effect from
Sep 14, 2018, 12:00 PM EDT
Expired
Sep 17, 2018, 5:00 AM EDT
In force
65 hr
Issued by
NWS Columbia, SC
Flood severity
None

Counties Calhoun County, SC, Chesterfield County, SC, Clarendon County, SC, Fairfield County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC

The radar

The Columbia radar (KCAE), 32 km from the middle of the area, began a volume at 19:32 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, 7.5 hours before the alert went out and 153 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, Charleston AFB, SC at 12:00Z on 2018-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 379 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, Charleston AFB, SC at 12:00Z on 2018-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 square meters per square second.1939Sfc1 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
379 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
801 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 4:47 PM EDTTropical Storm WarningCAECalhoun, Chesterfield, Clarendon, Fairfield, Kershaw, Lee and 3 more48 hr

Nearby

Flash Flood Watches in South Carolina, 2018Every flash flood watch 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.