Alert archive / South Carolina
Weather alerts in South Carolina, 2022
3,002 weather alerts in 2022, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered any part of the state, so the counties below add up to more than the state.
Weather alerts by county
Each county as a circle sized by its count in 2022. Tap one for its archive.
- Alerts
- 3,002
- Warnings
- 854
- Watches
- 73
- Advisories
- 631
- Busiest month
- July693 alerts
- Busiest day
- April 5, 202290 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
17 of 59 tornado warnings covering South Carolina in 2022 had a tornado report inside them; 30 of 42 tornado reports fell inside a warning, on average 18 minutes after it went out.
South Carolina, 2022
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 59 | 17 | 71% | 42 | 71% | 18 min |
| Severe thunderstorm warnings | 476 | 305 | 36% | 861 | 80% | 20 min |
| Flash flood warnings | 47 | 25 | 47% | 73 | 84% | 91 min |
Each office's whole area, 2022
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Columbia, SC: tornado warnings | 19 | 7 | 63% | 12 | 100% | 15 min |
| NWS Columbia, SC: severe thunderstorm warnings | 174 | 138 | 21% | 375 | 88% | 18 min |
| NWS Columbia, SC: flash flood warnings | 14 | 11 | 21% | 43 | 81% | 38 min |
| NWS Charleston, SC: tornado warnings | 16 | 8 | 50% | 33 | 79% | 27 min |
| NWS Charleston, SC: severe thunderstorm warnings | 130 | 75 | 42% | 389 | 70% | 21 min |
| NWS Charleston, SC: flash flood warnings | 7 | 4 | 43% | 13 | 62% | 356 min |
| NWS Wilmington, NC: tornado warnings | 15 | 2 | 87% | 3 | 67% | 5 min |
| NWS Wilmington, NC: severe thunderstorm warnings | 89 | 36 | 60% | 95 | 83% | 24 min |
| NWS Wilmington, NC: flash flood warnings | 14 | 8 | 43% | 20 | 90% | 62 min |
| NWS Greenville-Spartanburg, SC: tornado warnings | 38 | 5 | 87% | 15 | 40% | 24 min |
| NWS Greenville-Spartanburg, SC: severe thunderstorm warnings | 324 | 170 | 48% | 455 | 68% | 18 min |
| NWS Greenville-Spartanburg, SC: flash flood warnings | 32 | 10 | 69% | 30 | 73% | 126 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
3,002 alerts are too many to list on one page. Narrow it to a product above, to a month in the chart, or to a county.
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Horry County273
- Georgetown County252
- Berkeley County215
- Lexington County213
- Richland County208
- Orangeburg County178
- Calhoun County175
- Aiken County167
- York County167
- Greenville County165
- Colleton County165
- Sumter County155
- Clarendon County152
- Spartanburg County152
- Oconee County148
- Marion County144
- Pickens County143
- Cherokee County142
- Florence County142
- Dorchester County141
- Kershaw County137
- Chester County137
- Chesterfield County136
- Williamsburg County135
- Charleston County133
- Fairfield County130
- Newberry County129
- Lancaster County128
- Anderson County127
- Darlington County126
- Marlboro County126
- Hampton County125
- Union County124
- Bamberg County123
- Barnwell County121
- Dillon County121
- Edgefield County118
- Lee County118
- Saluda County118
- Laurens County112
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20212023
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.