Alert archive / South Carolina
Weather alerts in South Carolina, 2023
2,600 weather alerts in 2023, 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 2023. Tap one for its archive.
- Alerts
- 2,600
- Warnings
- 817
- Watches
- 85
- Advisories
- 576
- Busiest month
- August525 alerts
- Busiest day
- August 15, 202374 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
8 of 35 tornado warnings covering South Carolina in 2023 had a tornado report inside them; 9 of 20 tornado reports fell inside a warning, on average 6 minutes after it went out.
South Carolina, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 35 | 8 | 77% | 20 | 45% | 6 min |
| Severe thunderstorm warnings | 399 | 284 | 29% | 887 | 77% | 21 min |
| Flash flood warnings | 35 | 25 | 29% | 53 | 83% | 105 min |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Columbia, SC: tornado warnings | 9 | 3 | 67% | 7 | 57% | 7 min |
| NWS Columbia, SC: severe thunderstorm warnings | 116 | 89 | 23% | 378 | 81% | 23 min |
| NWS Columbia, SC: flash flood warnings | 14 | 11 | 21% | 30 | 90% | 77 min |
| NWS Greenville-Spartanburg, SC: tornado warnings | 14 | 3 | 79% | 11 | 27% | 2 min |
| NWS Greenville-Spartanburg, SC: severe thunderstorm warnings | 392 | 296 | 24% | 895 | 86% | 21 min |
| NWS Greenville-Spartanburg, SC: flash flood warnings | 20 | 10 | 50% | 28 | 93% | 93 min |
| NWS Wilmington, NC: tornado warnings | 15 | 1 | 93% | 3 | 33% | 4 min |
| NWS Wilmington, NC: severe thunderstorm warnings | 64 | 30 | 53% | 78 | 62% | 22 min |
| NWS Wilmington, NC: flash flood warnings | 15 | 11 | 27% | 28 | 93% | 134 min |
| NWS Charleston, SC: tornado warnings | 20 | 3 | 85% | 8 | 75% | 8 min |
| NWS Charleston, SC: severe thunderstorm warnings | 96 | 60 | 38% | 367 | 69% | 23 min |
| NWS Charleston, SC: flash flood warnings | 8 | 5 | 38% | 18 | 67% | 150 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
2,600 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 County242
- Georgetown County210
- Richland County198
- Berkeley County193
- Lexington County191
- Greenville County186
- Spartanburg County168
- Calhoun County154
- Aiken County150
- Laurens County146
- Pickens County141
- Colleton County138
- Edgefield County137
- Orangeburg County137
- Anderson County133
- Clarendon County131
- Oconee County128
- York County125
- Charleston County124
- Dorchester County123
- Hampton County121
- Cherokee County121
- Sumter County121
- Saluda County119
- Greenwood County118
- McCormick County118
- Marion County116
- Newberry County112
- Fairfield County110
- Kershaw County109
- Dillon County107
- Barnwell County105
- Florence County104
- Union County103
- Williamsburg County102
- Lee County101
- Marlboro County100
- Jasper County100
- Abbeville County99
- Allendale County94
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20222024
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.