Alert archive / South Carolina
Weather alerts in South Carolina, 2019
2,772 weather alerts in 2019, 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 2019. Tap one for its archive.
- Alerts
- 2,772
- Warnings
- 725
- Watches
- 75
- Advisories
- 563
- Busiest month
- July545 alerts
- Busiest day
- April 19, 201997 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
14 of 54 tornado warnings covering South Carolina in 2019 had a tornado report inside them; 22 of 26 tornado reports fell inside a warning, on average 13 minutes after it went out.
South Carolina, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 54 | 14 | 74% | 26 | 85% | 13 min |
| Severe thunderstorm warnings | 422 | 282 | 33% | 958 | 83% | 23 min |
| Flash flood warnings | 18 | 12 | 33% | 19 | 74% | 132 min |
Each office's whole area, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Columbia, SC: tornado warnings | 20 | 6 | 70% | 20 | 75% | 14 min |
| NWS Columbia, SC: severe thunderstorm warnings | 155 | 114 | 26% | 469 | 84% | 22 min |
| NWS Columbia, SC: flash flood warnings | 5 | 3 | 40% | 5 | 60% | 53 min |
| NWS Greenville-Spartanburg, SC: tornado warnings | 23 | 0 | 100% | 4 | 0% | |
| NWS Greenville-Spartanburg, SC: severe thunderstorm warnings | 279 | 181 | 35% | 442 | 73% | 17 min |
| NWS Greenville-Spartanburg, SC: flash flood warnings | 30 | 20 | 33% | 68 | 79% | 100 min |
| NWS Charleston, SC: tornado warnings | 9 | 1 | 89% | 4 | 75% | 3 min |
| NWS Charleston, SC: severe thunderstorm warnings | 110 | 78 | 29% | 424 | 83% | 28 min |
| NWS Charleston, SC: flash flood warnings | 1 | 1 | 0% | 1 | 100% | 303 min |
| NWS Wilmington, NC: tornado warnings | 49 | 21 | 57% | 32 | 91% | 15 min |
| NWS Wilmington, NC: severe thunderstorm warnings | 91 | 42 | 54% | 110 | 86% | 20 min |
| NWS Wilmington, NC: flash flood warnings | 12 | 9 | 25% | 15 | 93% | 93 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
2,772 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 County253
- Richland County202
- Georgetown County196
- Lexington County195
- Calhoun County178
- Spartanburg County163
- Greenville County161
- Berkeley County151
- Edgefield County146
- York County146
- Kershaw County144
- Clarendon County143
- Newberry County137
- Chesterfield County137
- Aiken County137
- Fairfield County137
- Saluda County135
- Colleton County135
- Sumter County132
- Cherokee County129
- Lee County126
- Laurens County126
- Bamberg County125
- McCormick County125
- Florence County124
- Dorchester County123
- Marlboro County123
- Pickens County122
- Anderson County119
- Oconee County118
- Williamsburg County117
- Chester County117
- Marion County115
- Union County114
- Barnwell County109
- Hampton County109
- Darlington County108
- Greenwood County107
- Lancaster County105
- Orangeburg County103
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20182020
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.