Alert archive / South Carolina / Flash Flood Warnings in 2018

Flash Flood Warning 1, NWS Columbia, SC

May 18, 2018Calhoun County, Orangeburg County, South Carolina

NWS Columbia, SC issued this flash flood warning at May 18, 2018, 10:40 AM EDT for Calhoun County, Orangeburg County, South Carolina. It was in force for 2 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: May 18, 2018, 10:40 AM EDT (14:40 UTC)
Expired: May 18, 2018, 12:45 PM EDT
In force: 2 hr
Issued by: NWS Columbia, SC
Area: Storm-based polygon
Flood severity: None

Counties Calhoun County, SC, Orangeburg County, SC

The radar

The Columbia radar (KCAE), 53 km from the middle of the area, began a volume at 14:42 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, 2.7 hours before the alert went out and 292 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: 246 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 626 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Columbia, SC wrote its last area forecast discussion before this flash flood warning went out at May 18, 8:36 AM EDT, 2 hours 4 minutes earlier.

Area forecast discussion, May 18, 8:36 AM EDT, 2 hours 4 minutes before

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Hazardous weather outlook, May 18, 3:24 AM EDT, 7 hours 16 minutes before

Hazardous Weather Outlook
National Weather Service Columbia SC
324 AM EDT Fri May 18 2018

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-190730-
Lincoln-McDuffie-Columbia-Richmond-Burke-Lancaster-Chesterfield-
McCormick-Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-
Richland-Lee-Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon-
Bamberg-
324 AM EDT Fri May 18 2018

This Hazardous Weather Outlook is for the Midlands of South Carolina
and the Central Savannah River area of Georgia.

.DAY ONE...Today and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 10:20 AM EDT	Areal Flood Advisory	CAE	Bamberg, Calhoun, Orangeburg	115 min
May 18, 11:24 AM EDT	Areal Flood Advisory	CAE	Calhoun, Kershaw, Lee, Richland, Sumter	3 hr
May 18, 12:37 PM EDT	Areal Flood Advisory	CAE	Bamberg, Calhoun, Clarendon, Lee, Orangeburg, Sumter	113 min
May 18, 12:43 PM EDT	Areal Flood Advisory	CAE	Chesterfield, Kershaw	2 hr
May 18, 4:37 PM EDT	Special Weather Statement	CAE	Burke	38 min
May 18, 4:50 PM EDT	Areal Flood Advisory	CAE	Lincoln	115 min
May 18, 4:57 PM EDT	Areal Flood Advisory	CAE	Burke	2 hr
May 18, 6:00 PM EDT	Flash Flood Warning	CAE	Burke	2 hr

Nearby

Flash Flood Warnings in South Carolina, 2018 Every 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.