Alert archive / South Carolina
Weather alerts in South Carolina, 2010
2,433 weather alerts in 2010, 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 2010. Tap one for its archive.
- Alerts
- 2,433
- Warnings
- 913
- Watches
- 76
- Advisories
- 576
- Busiest month
- July584 alerts
- Busiest day
- July 26, 201083 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 44 tornado warnings covering South Carolina in 2010 had a tornado report inside them; 21 of 24 tornado reports fell inside a warning, on average 8 minutes after it went out.
South Carolina, 2010
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 44 | 17 | 61% | 24 | 88% | 8 min |
| Severe thunderstorm warnings | 652 | 456 | 30% | 839 | 82% | 24 min |
| Flash flood warnings | 39 | 26 | 33% | 51 | 82% | 74 min |
Each office's whole area, 2010
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Greenville-Spartanburg, SC: tornado warnings | 50 | 11 | 78% | 16 | 81% | 16 min |
| NWS Greenville-Spartanburg, SC: severe thunderstorm warnings | 470 | 362 | 23% | 722 | 81% | 25 min |
| NWS Greenville-Spartanburg, SC: flash flood warnings | 56 | 39 | 30% | 99 | 88% | 108 min |
| NWS Wilmington, NC: tornado warnings | 4 | 1 | 75% | 6 | 67% | 13 min |
| NWS Wilmington, NC: severe thunderstorm warnings | 78 | 54 | 31% | 123 | 72% | 16 min |
| NWS Wilmington, NC: flash flood warnings | 14 | 13 | 7% | 58 | 79% | 198 min |
| NWS Columbia, SC: tornado warnings | 14 | 9 | 36% | 9 | 100% | 7 min |
| NWS Columbia, SC: severe thunderstorm warnings | 240 | 151 | 37% | 279 | 87% | 19 min |
| NWS Columbia, SC: flash flood warnings | 13 | 6 | 54% | 12 | 83% | 26 min |
| NWS Charleston, SC: tornado warnings | 10 | 1 | 90% | 1 | 100% | 8 min |
| NWS Charleston, SC: severe thunderstorm warnings | 211 | 128 | 39% | 292 | 77% | 23 min |
| NWS Charleston, SC: flash flood warnings | 13 | 8 | 38% | 21 | 76% | 44 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
2,433 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.
- Berkeley County289
- Richland County232
- Colleton County203
- Dorchester County197
- Lexington County194
- Hampton County180
- Greenville County179
- Anderson County173
- Calhoun County172
- York County168
- Aiken County166
- Sumter County165
- Laurens County163
- Charleston County162
- Allendale County162
- Florence County156
- Kershaw County153
- Spartanburg County152
- Greenwood County150
- Cherokee County148
- Abbeville County146
- Chester County145
- Clarendon County145
- Darlington County144
- Marion County143
- Williamsburg County141
- Union County139
- Marlboro County139
- Edgefield County138
- Dillon County137
- Lee County136
- Fairfield County135
- Barnwell County134
- McCormick County132
- Horry County132
- Saluda County131
- Bamberg County129
- Chesterfield County129
- Pickens County129
- Oconee County129
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20092011
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.