Alert archive / South Carolina / Chester County
Weather alerts in Chester County, South Carolina, 2021
87 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Chester County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 87
- Warnings
- 13
- Watches
- 6
- Advisories
- 20
- Busiest month
- August22 alerts
- Busiest day
- August 17, 20216 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 2 tornado warnings covering Chester County in 2021 had a tornado report inside them.
Chester County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 8 | 2 | 75% | 1 | 100% | 24 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Greenville-Spartanburg, SC: tornado warnings | 63 | 8 | 87% | 23 | 78% | 24 min |
| NWS Greenville-Spartanburg, SC: severe thunderstorm warnings | 176 | 95 | 46% | 267 | 63% | 17 min |
| NWS Greenville-Spartanburg, SC: flash flood warnings | 47 | 22 | 53% | 57 | 70% | 94 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
Every alert, in the order issued. Times are local, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Dec 31, 10:03 PM EST | Dense Fog Advisory | GSP | 9 hr |
| Jan 1, 3:37 PM EST | Special Weather Statement | GSP | 53 min |
| Jan 1, 5:30 PM EST | Special Weather Statement | GSP | 60 min |
| Jan 2, 5:20 AM EST | Dense Fog Advisory | GSP | 7 hr |
| Jan 13, 3:01 AM EST | Freezing Fog Advisory | GSP | 7 hr |
| Jan 15, 9:33 PM EST | Dense Fog Advisory | GSP | 8 hr |
| Jan 25, 4:08 PM EST | Dense Fog Advisory | GSP | 11 hr |
| Jan 26, 6:41 PM EST | Dense Fog Advisory | GSP | 9 hr |
| Feb 11, 3:43 AM EST | Dense Fog Advisory | GSP | 8 hr |
| Feb 15, 8:06 PM EST | Special Weather Statement | GSP | 24 min |
| Mar 18, 2:08 PM EDT | Tornado Watch | SPC | 4 hr |
| Mar 18, 3:10 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 18, 4:45 PM EDT | Special Weather Statement | GSP | 30 min |
| Mar 25, 4:54 PM EDT | Tornado Warning | GSP | 51 min |
| Mar 25, 5:47 PM EDT | Severe Thunderstorm Warning | GSP | 28 min |
| Mar 26, 12:20 AM EDT | Special Weather Statement | GSP | 40 min |
| Mar 26, 4:25 AM EDT | Special Weather Statement | GSP | 35 min |
| Mar 26, 4:44 AM EDT | Severe Thunderstorm Warning | GSP | 31 min |
| Mar 26, 5:20 AM EDT | Special Weather Statement | GSP | 40 min |
| Mar 28, 12:38 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 28, 1:09 PM EDT | Special Weather Statement | GSP | 51 min |
| Mar 31, 2:22 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Mar 31, 2:59 PM EDT | Freeze Watch | GSP | 12 hr |
| Apr 1, 3:27 AM EDT | Freeze Warning | GSP | 30 hr |
| Apr 2, 9:03 AM EDT | Freeze Warning | GSP | 24 hr |
| Apr 3, 9:08 AM EDT | Frost Advisory | GSP | 24 hr |
| Apr 10, 5:35 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Apr 20, 1:30 PM EDT | Fire Weather Watch | GSP | 14 hr |
| Apr 21, 3:45 AM EDT | Red Flag Warning | GSP | 16 hr |
| Apr 21, 2:44 PM EDT | Frost Advisory | GSP | 17 hr |
| Apr 22, 3:35 AM EDT | Frost Advisory | GSP | 29 hr |
| May 3, 1:03 PM EDT | Mesoscale Discussion | SPC | 87 min |
| May 3, 1:25 PM EDT | Tornado Watch | SPC | 6 hr |
| May 4, 3:53 PM EDT | Severe Thunderstorm Warning | GSP | 52 min |
| May 4, 4:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| May 28, 4:46 PM EDT | Special Weather Statement | GSP | 29 min |
| Jun 5, 5:22 PM EDT | Special Weather Statement | GSP | 23 min |
| Jun 5, 6:21 PM EDT | Areal Flood Advisory | GSP | 76 min |
| Jun 7, 4:41 PM EDT | Special Weather Statement | GSP | 34 min |
| Jun 7, 5:11 PM EDT | Special Weather Statement | GSP | 34 min |
| Jun 14, 6:32 PM EDT | Special Weather Statement | GSP | 28 min |
| Jul 1, 7:08 PM EDT | Special Weather Statement | GSP | 37 min |
| Jul 9, 3:10 PM EDT | Special Weather Statement | GSP | 35 min |
| Jul 12, 4:07 PM EDT | Special Weather Statement | GSP | 23 min |
| Jul 12, 4:36 PM EDT | Special Weather Statement | GSP | 24 min |
| Jul 12, 9:58 PM EDT | Special Weather Statement | GSP | 47 min |
| Jul 16, 12:58 PM EDT | Severe Thunderstorm Warning | GSP | 32 min |
| Jul 16, 1:43 PM EDT | Special Weather Statement | GSP | 32 min |
| Jul 17, 4:53 PM EDT | Special Weather Statement | GSP | 37 min |
| Jul 18, 10:54 PM EDT | Areal Flood Advisory | GSP | 3 hr |
| Jul 26, 6:11 PM EDT | Special Weather Statement | GSP | 34 min |
| Aug 9, 4:12 PM EDT | Special Weather Statement | GSP | 48 min |
| Aug 9, 4:42 PM EDT | Special Weather Statement | GSP | 48 min |
| Aug 10, 3:58 PM EDT | Special Weather Statement | GSP | 32 min |
| Aug 10, 4:20 PM EDT | Severe Thunderstorm Warning | GSP | 20 min |
| Aug 14, 3:09 PM EDT | Severe Thunderstorm Warning | GSP | 51 min |
| Aug 14, 3:56 PM EDT | Severe Thunderstorm Warning | GSP | 31 min |
| Aug 14, 4:28 PM EDT | Special Weather Statement | GSP | 32 min |
| Aug 15, 4:54 PM EDT | Special Weather Statement | GSP | 36 min |
| Aug 17, 10:42 AM EDT | Tornado Watch | SPC | 8 hr |
| Aug 17, 12:35 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Aug 17, 3:25 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 17, 5:37 PM EDT | Tornado Warning | GSP | 38 min |
| Aug 17, 5:55 PM EDT | Mesoscale Discussion | SPC | 65 min |
| Aug 17, 6:28 PM EDT | Tornado Watch | SPC | 10 hr |
| Aug 19, 6:29 PM EDT | Special Weather Statement | GSP | 31 min |
| Aug 19, 6:55 PM EDT | Special Weather Statement | GSP | 35 min |
| Aug 21, 8:09 PM EDT | Severe Thunderstorm Warning | GSP | 51 min |
| Aug 21, 9:01 PM EDT | Special Weather Statement | GSP | 44 min |
| Aug 23, 3:53 AM EDT | Dense Fog Advisory | GSP | 5 hr |
| Aug 31, 3:45 PM EDT | Special Weather Statement | GSP | 30 min |
| Aug 31, 5:16 PM EDT | Special Weather Statement | GSP | 29 min |
| Aug 31, 6:07 PM EDT | Special Weather Statement | GSP | 38 min |
| Sep 1, 6:01 PM EDT | Special Weather Statement | GSP | 29 min |
| Sep 8, 5:29 PM EDT | Special Weather Statement | GSP | 31 min |
| Sep 22, 2:44 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Nov 4, 3:23 AM EDT | Frost Advisory | GSP | 31 hr |
| Nov 7, 2:30 PM EST | Frost Advisory | GSP | 19 hr |
| Dec 8, 10:56 PM EST | Dense Fog Advisory | GSP | 11 hr |
| Dec 10, 8:32 PM EST | Dense Fog Advisory | GSP | 15 hr |
| Dec 11, 4:13 PM EST | Special Weather Statement | GSP | 62 min |
| Dec 11, 5:10 PM EST | Special Weather Statement | GSP | 35 min |
| Dec 18, 3:29 AM EST | Dense Fog Advisory | GSP | 8 hr |
| Dec 18, 5:32 PM EST | Special Weather Statement | GSP | 28 min |
| Dec 25, 3:44 AM EST | Wind Advisory | GSP | 21 hr |
| Dec 27, 3:31 AM EST | Dense Fog Advisory | GSP | 8 hr |
| Dec 30, 1:44 AM EST | Special Weather Statement | GSP | 46 min |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 8 |
| Tornado Warning | 2 |
| Tornado Watch | 4 |
| Mesoscale Discussion | 10 |
| Special Weather Statement | 38 |
| Flooding | |
| Areal Flood Advisory | 2 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 1 |
| Frost Advisory | 5 |
| Wind and dust | |
| Wind Advisory | 1 |
| Fire | |
| Red Flag Warning | 1 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 11 |
| Freezing Fog Advisory | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.