Flash Flood Warnings in South Carolina, 2018

By month

28 of 37 flash flood warnings covering South Carolina in 2018 had a flash flood report inside them; 76 of 88 flash flood reports fell inside a warning, on average 121 minutes after it went out.

South Carolina, 2018

Each office's whole area, 2018

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.

• Horry County11
• Dillon County7
• Richland County6
• Florence County5
• Marion County5
• Lexington County4
• Marlboro County4
• Chesterfield County4
• Darlington County4
• Georgetown County4
• Cherokee County3
• York County3
• Spartanburg County2
• Charleston County2
• Kershaw County2
• Lancaster County2
• Williamsburg County2
• Greenwood County1
• Laurens County1
• Calhoun County1
• Orangeburg County1
• Chester County1
• Sumter County1
• Aiken County1
• Greenville County1

1. September 16, 201812flash flood warnings
2. September 17, 20184flash flood warnings
3. October 11, 20183flash flood warnings
4. July 23, 20182flash flood warnings
5. July 29, 20182flash flood warnings
6. April 15, 20181flash flood warnings
7. May 18, 20181flash flood warnings
8. May 28, 20181flash flood warnings
9. May 31, 20181flash flood warnings
10. June 2, 20181flash flood warnings
11. June 12, 20181flash flood warnings
12. July 12, 20181flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20172019

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.