Alert archive / South Carolina / Flash Flood Watches in 2020

Flash Flood Watch 5, NWS Columbia, SC

May 27, 20207 counties in South Carolina

NWS Columbia, SC issued this flash flood watch at May 27, 2020, 8:33 AM EDT for 7 counties in South Carolina. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued
May 27, 2020, 8:33 AM EDT (12:33 UTC)
Expired
May 27, 2020, 10:00 PM EDT
In force
13 hr
Issued by
NWS Columbia, SC
Flood severity
None

Counties Calhoun County, SC, Chesterfield County, SC, Clarendon County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Sumter County, SC

The radar

The Columbia radar (KCAE), 67 km from the middle of the area, began a volume at 12:37 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

Charleston AFB, SC (KCHS), launched 12:00Z, 0.6 hours before the alert went out and 145 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 2020-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 158 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 2020-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 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
158 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
458 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
69 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
May 27, 11:33 AM EDTAreal Flood AdvisoryCAEClarendon, Kershaw, Lee, Richland, Sumter3 hr
May 27, 2:30 PM EDTAreal Flood AdvisoryCAEChesterfield, Fairfield, Kershaw, Lancaster, Lee, Richland and 1 more3 hr
May 27, 5:22 PM EDTAreal Flood AdvisoryCAEChesterfield, Fairfield, Kershaw, Lancaster3 hr

Nearby

Flash Flood Watches in South Carolina, 2020Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.