Alert archive / South Carolina / Allendale County
Weather alerts in Allendale County, South Carolina, 2021
71 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Allendale County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 71
- Warnings
- 14
- Watches
- 10
- Advisories
- 22
- Busiest month
- March11 alerts
- Busiest day
- February 18, 20213 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Allendale County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 2 | 2 | 0% | 2 | 50% | 10 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 Charleston, SC: tornado warnings | 15 | 2 | 87% | 6 | 50% | 6 min |
| NWS Charleston, SC: severe thunderstorm warnings | 53 | 30 | 43% | 126 | 40% | 19 min |
| NWS Charleston, SC: flash flood warnings | 1 | 1 | 0% | 3 | 33% | 8 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, 9:28 PM EST | Dense Fog Advisory | CHS | 13 hr |
| Jan 2, 12:30 PM EST | Flash Flood Watch | CHS | 12 hr |
| Jan 6, 9:27 PM EST | River Flood Warning | CHS | 4 days |
| Jan 15, 8:35 PM EST | Dense Fog Advisory | CHS | 3 hr |
| Jan 23, 12:37 AM EST | Dense Fog Advisory | CHS | 7 hr |
| Jan 27, 11:39 AM EST | Special Weather Statement | CHS | 21 min |
| Feb 11, 2:57 AM EST | Dense Fog Advisory | CHS | 7 hr |
| Feb 11, 6:28 PM EST | Dense Fog Advisory | CHS | 16 hr |
| Feb 18, 7:15 AM EST | Flash Flood Watch | CHS | 20 hr |
| Feb 18, 10:40 AM EST | River Flood Warning | CHS | 21 days |
| Feb 18, 4:40 PM EST | Areal Flood Advisory | CHS | 110 min |
| Mar 2, 8:46 PM EST | River Flood Warning | CHS | 5 days |
| Mar 7, 3:12 AM EST | Freeze Watch | CHS | 12 hr |
| Mar 7, 3:22 PM EST | Freeze Warning | CHS | 17 hr |
| Mar 8, 12:58 PM EST | Freeze Warning | CHS | 19 hr |
| Mar 18, 11:42 AM EDT | Tornado Watch | SPC | 6 hr |
| Mar 26, 1:56 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Mar 28, 12:38 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 28, 5:51 PM EDT | Mesoscale Discussion | SPC | 54 min |
| Mar 31, 4:04 PM EDT | Special Weather Statement | CHS | 26 min |
| Mar 31, 4:26 PM EDT | Special Weather Statement | CHS | 34 min |
| Mar 31, 6:24 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 1, 3:08 PM EDT | Freeze Warning | CHS | 17 hr |
| Apr 2, 8:28 AM EDT | Freeze Warning | CHS | 25 hr |
| Apr 2, 9:43 AM EDT | River Flood Warning | CHS | 7 days |
| Apr 3, 3:01 PM EDT | Frost Advisory | CHS | 17 hr |
| Apr 20, 3:19 PM EDT | Fire Weather Watch | CHS | 10 hr |
| Apr 21, 1:44 AM EDT | Red Flag Warning | CHS | 18 hr |
| May 3, 4:26 PM EDT | Mesoscale Discussion | SPC | 94 min |
| May 3, 5:50 PM EDT | Severe Thunderstorm Warning | CHS | 55 min |
| May 3, 8:15 PM EDT | Areal Flood Advisory | CHS | 2 hr |
| May 6, 3:00 PM EDT | Fire Weather Watch | CHS | 12 hr |
| May 7, 3:05 AM EDT | Red Flag Warning | CHS | 16 hr |
| Jun 6, 4:04 PM EDT | Special Weather Statement | CHS | 26 min |
| Jun 12, 1:14 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 12, 5:58 PM EDT | Areal Flood Advisory | CHS | 2 hr |
| Jun 15, 12:57 PM EDT | Mesoscale Discussion | SPC | 63 min |
| Jun 15, 7:15 PM EDT | Special Weather Statement | CHS | 30 min |
| Jun 20, 2:58 AM EDT | Flash Flood Watch | CHS | 24 hr |
| Jun 20, 8:40 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 7, 4:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jul 7, 7:25 PM EDT | Tornado Watch | SPC | 11 hr |
| Jul 9, 5:46 PM EDT | Special Weather Statement | CHS | 29 min |
| Jul 12, 6:04 PM EDT | Special Weather Statement | CHS | 11 min |
| Jul 17, 5:45 PM EDT | Special Weather Statement | CHS | 30 min |
| Jul 18, 12:17 PM EDT | Severe Thunderstorm Warning | CHS | 43 min |
| Jul 22, 5:56 PM EDT | Special Weather Statement | CAE | 34 min |
| Jul 29, 3:36 PM EDT | Heat Advisory | CHS | 28 hr |
| Jul 31, 1:40 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 31, 10:08 PM EDT | Special Weather Statement | CHS | 22 min |
| Aug 1, 9:22 PM EDT | Special Weather Statement | CHS | 23 min |
| Aug 6, 6:29 PM EDT | Areal Flood Advisory | CHS | 2 hr |
| Aug 21, 9:46 PM EDT | Areal Flood Advisory | CHS | 3 hr |
| Aug 25, 4:28 PM EDT | Areal Flood Advisory | CHS | 92 min |
| Sep 22, 4:48 PM EDT | Special Weather Statement | CHS | 27 min |
| Oct 3, 6:09 AM EDT | Dense Fog Advisory | CHS | 5 hr |
| Oct 20, 10:34 AM EDT | River Flood Warning | CHS | 4 days |
| Nov 13, 4:33 AM EST | Frost Advisory | CHS | 27 hr |
| Nov 15, 2:41 PM EST | Frost Advisory | CHS | 17 hr |
| Nov 22, 3:15 AM EST | Freeze Watch | CHS | 24 hr |
| Nov 23, 3:07 AM EST | Freeze Warning | CHS | 30 hr |
| Dec 5, 2:20 AM EST | Dense Fog Advisory | CHS | 7 hr |
| Dec 6, 1:04 AM EST | Dense Fog Advisory | CHS | 8 hr |
| Dec 9, 5:49 AM EST | Dense Fog Advisory | CHS | 3 hr |
| Dec 11, 7:42 PM EST | Special Weather Statement | CHS | 33 min |
| Dec 16, 9:27 PM EST | Dense Fog Advisory | CHS | 13 hr |
| Dec 17, 9:29 PM EST | Dense Fog Advisory | CHS | 12 hr |
| Dec 26, 9:48 PM EST | Dense Fog Advisory | CHS | 13 hr |
| Dec 30, 2:05 PM EST | Severe Thunderstorm Watch | SPC | 7 hr |
| Dec 30, 3:25 PM EST | Special Weather Statement | CHS | 35 min |
| Dec 30, 4:27 PM EST | Special Weather Statement | CHS | 48 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 | 2 |
| Severe Thunderstorm Watch | 1 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 10 |
| Special Weather Statement | 15 |
| Flooding | |
| River Flood Warning | 5 |
| Flash Flood Watch | 3 |
| Areal Flood Advisory | 6 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 5 |
| Freeze Watch | 2 |
| Frost Advisory | 3 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 12 |
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.