Alert archive / South Carolina / Flash Flood Warnings
Flash Flood Warnings in South Carolina, 2017
38 flash flood warnings in 2017. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of flash flood warnings reaches back to 1986.
Flash Flood Warnings by county
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Flash Flood Warnings
- 38
- Busiest month
- April11 flash flood warnings
- Busiest day
- April 24, 20178 flash flood warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
21 of 38 flash flood warnings covering South Carolina in 2017 had a flash flood report inside them; 47 of 49 flash flood reports fell inside a warning, on average 55 minutes after it went out.
South Carolina, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Flash flood warnings | 38 | 21 | 45% | 49 | 96% | 55 min |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Columbia, SC: flash flood warnings | 19 | 13 | 32% | 40 | 93% | 36 min |
| NWS Charleston, SC: flash flood warnings | 10 | 5 | 50% | 6 | 100% | 247 min |
| NWS Wilmington, NC: flash flood warnings | 9 | 3 | 67% | 8 | 88% | 49 min |
| NWS Greenville-Spartanburg, SC: flash flood warnings | 23 | 14 | 39% | 50 | 64% | 48 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
The alerts
Every alert, in the order issued. Times are local, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 30, 3:58 PM EDT | Flash Flood Warning | CAE | Richland | 62 min |
| Apr 3, 4:51 PM EDT | Flash Flood Warning | CAE | Richland | 114 min |
| Apr 5, 2:32 PM EDT | Flash Flood Warning | CAE | Lexington, Richland | 118 min |
| Apr 23, 2:12 PM EDT | Flash Flood Warning | ILM | Georgetown, Williamsburg | 2 hr |
| Apr 24, 12:05 AM EDT | Flash Flood Warning | CAE | Richland | 115 min |
| Apr 24, 7:58 AM EDT | Flash Flood Warning | CHS | Charleston | 2 hr |
| Apr 24, 8:10 AM EDT | Flash Flood Warning | ILM | Georgetown, Williamsburg | 6 hr |
| Apr 24, 9:22 AM EDT | Flash Flood Warning | ILM | Williamsburg | 3 hr |
| Apr 24, 9:46 AM EDT | Flash Flood Warning | CHS | Charleston | 89 min |
| Apr 24, 10:31 AM EDT | Flash Flood Warning | ILM | Darlington, Dillon, Florence, Marion, Marlboro, Williamsburg | 3 hr |
| Apr 24, 5:22 PM EDT | Flash Flood Warning | CAE | Orangeburg | 53 min |
| Apr 24, 6:49 PM EDT | Flash Flood Warning | CAE | Orangeburg | 56 min |
| May 22, 1:48 PM EDT | Flash Flood Warning | CAE | McCormick | 3 hr |
| May 22, 1:59 PM EDT | Flash Flood Warning | CAE | Aiken, Kershaw, Lexington, Richland, Saluda | 5 hr |
| May 22, 3:03 PM EDT | Flash Flood Warning | CAE | Saluda | 117 min |
| May 22, 6:13 PM EDT | Flash Flood Warning | ILM | Georgetown, Horry, Marion | 3 hr |
| May 23, 5:23 PM EDT | Flash Flood Warning | CHS | Charleston | 6 hr |
| May 29, 7:48 PM EDT | Flash Flood Warning | CAE | Lexington, Richland | 57 min |
| Jun 15, 10:18 PM EDT | Flash Flood Warning | CAE | Lexington, Richland | 117 min |
| Jun 15, 11:50 PM EDT | Flash Flood Warning | CAE | Lexington, Richland | 115 min |
| Jul 9, 7:11 PM EDT | Flash Flood Warning | ILM | Horry | 3 hr |
| Jul 9, 11:35 PM EDT | Flash Flood Warning | ILM | Marlboro | 3 hr |
| Jul 15, 8:34 PM EDT | Flash Flood Warning | CAE | Aiken | 3 hr |
| Jul 16, 6:20 PM EDT | Flash Flood Warning | CAE | Kershaw, Richland | 115 min |
| Jul 18, 8:38 PM EDT | Flash Flood Warning | CAE | Chesterfield | 2 hr |
| Jul 23, 4:39 PM EDT | Flash Flood Warning | CAE | Chesterfield | 2 hr |
| Jul 23, 6:58 PM EDT | Flash Flood Warning | CAE | Richland | 92 min |
| Jul 24, 4:14 PM EDT | Flash Flood Warning | CAE | Richland | 91 min |
| Aug 11, 11:42 AM EDT | Flash Flood Warning | GSP | Greenville, Spartanburg | 3 hr |
| Aug 12, 12:13 AM EDT | Flash Flood Warning | GSP | Oconee | 3 hr |
| Aug 12, 1:05 AM EDT | Flash Flood Warning | GSP | Chester, York | 3 hr |
| Sep 11, 8:16 AM EDT | Flash Flood Warning | CHS | Jasper | 8 hr |
| Sep 11, 9:22 AM EDT | Flash Flood Warning | CHS | Beaufort, Jasper | 8 hr |
| Sep 11, 10:44 AM EDT | Flash Flood Warning | CHS | Allendale, Hampton, Jasper | 7 hr |
| Sep 11, 11:24 AM EDT | Flash Flood Warning | CHS | Berkeley, Charleston, Colleton, Dorchester | 15 hr |
| Sep 11, 12:54 PM EDT | Flash Flood Warning | CHS | Allendale, Colleton, Dorchester, Hampton | 9 hr |
| Sep 11, 3:10 PM EDT | Flash Flood Warning | CHS | Berkeley, Colleton, Dorchester | 7 hr |
| Sep 12, 2:45 AM EDT | Flash Flood Warning | CAE | Richland | 90 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Richland County12
- Lexington County5
- Williamsburg County4
- Charleston County4
- Georgetown County3
- Jasper County3
- Colleton County3
- Dorchester County3
- Marion County2
- Marlboro County2
- Orangeburg County2
- Aiken County2
- Kershaw County2
- Saluda County2
- Horry County2
- Chesterfield County2
- Allendale County2
- Hampton County2
- Berkeley County2
- Darlington County1
- Dillon County1
- Florence County1
- McCormick County1
- Greenville County1
- Spartanburg County1
- Oconee County1
- Chester County1
- York County1
- Beaufort County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20162018
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.