Alert archive / South Dakota / Gregory County
Weather alerts in Gregory County, South Dakota, 2024
119 weather alerts in 2024, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Gregory County and its neighbors
Each county as a circle sized by its count in 2024. Tap one for its archive.
- Alerts
- 119
- Warnings
- 33
- Watches
- 24
- Advisories
- 41
- Busiest month
- July21 alerts
- Busiest day
- July 29, 20247 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Gregory County, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 12 | 8 | 33% | 17 | 94% | 27 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 27 | 4 | 85% | 12 | 50% | 9 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 147 | 91 | 38% | 246 | 76% | 19 min |
| NWS Sioux Falls, SD: flash flood warnings | 34 | 29 | 15% | 54 | 89% | 90 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, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 6, 3:09 AM CST | Winter Storm Watch | FSD | 35 hr |
| Jan 7, 2:58 AM CST | Winter Storm Warning | FSD | 63 hr |
| Jan 10, 3:12 PM CST | Winter Weather Advisory | FSD | 51 hr |
| Jan 11, 3:08 AM CST | Wind Chill Advisory | FSD | 39 hr |
| Jan 11, 2:45 PM CST | Blizzard Warning | FSD | 57 hr |
| Jan 11, 2:45 PM CST | Wind Chill Warning | FSD | 5 days |
| Jan 15, 2:18 AM CST | Wind Chill Advisory | FSD | 34 hr |
| Jan 17, 2:09 PM CST | Winter Weather Advisory | FSD | 36 hr |
| Jan 19, 2:26 AM CST | Wind Chill Advisory | FSD | 32 hr |
| Jan 22, 2:34 PM CST | Dense Fog Advisory | FSD | 21 hr |
| Jan 24, 5:41 PM CST | Dense Fog Advisory | FSD | 18 hr |
| Jan 25, 2:21 PM CST | Dense Fog Advisory | FSD | 22 hr |
| Jan 26, 12:01 PM CST | Dense Fog Advisory | FSD | 24 hr |
| Feb 1, 2:38 AM CST | Dense Fog Advisory | FSD | 11 hr |
| Feb 2, 2:38 AM CST | Dense Fog Advisory | FSD | 4 days |
| Feb 14, 1:53 PM CST | Winter Weather Advisory | FSD | 37 hr |
| Feb 25, 2:04 PM CST | Red Flag Warning | FSD | 27 hr |
| Feb 26, 2:01 PM CST | Wind Advisory | FSD | 31 hr |
| Mar 2, 2:51 PM CST | Fire Weather Watch | FSD | 12 hr |
| Mar 3, 2:37 AM CST | Red Flag Warning | FSD | 15 hr |
| Mar 3, 6:47 AM CST | Dense Fog Advisory | FSD | 2 hr |
| Mar 6, 3:24 AM CST | Red Flag Warning | FSD | 15 hr |
| Mar 6, 3:25 AM CST | Wind Advisory | FSD | 15 hr |
| Mar 10, 3:35 AM CDT | Fire Weather Watch | FSD | 23 hr |
| Mar 11, 2:37 AM CDT | Red Flag Warning | FSD | 16 hr |
| Mar 15, 3:42 PM CDT | Fire Weather Watch | FSD | 23 hr |
| Mar 22, 3:41 AM CDT | Winter Storm Watch | FSD | 59 hr |
| Mar 23, 3:40 AM CDT | Winter Weather Advisory | FSD | 35 hr |
| Mar 24, 3:46 AM CDT | Blizzard Warning | FSD | 41 hr |
| Mar 25, 3:23 AM CDT | Winter Weather Advisory | FSD | 34 hr |
| Apr 5, 1:58 PM CDT | Wind Advisory | FSD | 35 hr |
| Apr 10, 3:18 AM CDT | Fire Weather Watch | FSD | 31 hr |
| Apr 10, 2:31 PM CDT | Red Flag Warning | FSD | 29 hr |
| May 5, 2:31 PM CDT | Wind Advisory | FSD | 28 hr |
| May 6, 12:18 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 7, 10:11 AM CDT | Wind Advisory | FSD | 9 hr |
| May 14, 4:53 PM CDT | Mesoscale Discussion | SPC | 67 min |
| May 23, 2:53 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 23, 3:25 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 23, 5:54 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 24, 9:50 AM CDT | Wind Advisory | FSD | 9 hr |
| May 26, 3:06 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 30, 2:27 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jun 2, 4:02 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Jun 2, 4:32 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 5, 3:06 AM CDT | Wind Advisory | FSD | 16 hr |
| Jun 12, 7:16 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 16, 8:38 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 16, 10:09 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 16, 10:13 PM CDT | Severe Thunderstorm Warning | FSD | 47 min |
| Jun 16, 11:34 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jun 16, 11:48 PM CDT | Flash Flood Warning | FSD | 6 hr |
| Jun 20, 3:26 AM CDT | Flood Watch | FSD | 64 hr |
| Jun 20, 4:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 21, 7:32 PM CDT | Flash Flood Warning | FSD | 3 hr |
| Jun 23, 2:59 AM CDT | Heat Advisory | FSD | 41 hr |
| Jul 12, 2:01 PM CDT | Heat Advisory | FSD | 30 hr |
| Jul 13, 2:09 PM CDT | Heat Advisory | FSD | 30 hr |
| Jul 14, 2:02 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 14, 2:20 AM CDT | Severe Thunderstorm Warning | FSD | 70 min |
| Jul 14, 3:28 AM CDT | Severe Thunderstorm Warning | FSD | 47 min |
| Jul 20, 5:05 AM CDT | Dense Fog Advisory | FSD | 4 hr |
| Jul 25, 5:40 AM CDT | Dense Fog Advisory | FSD | 3 hr |
| Jul 28, 9:00 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 29, 12:39 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 29, 1:56 AM CDT | Severe Thunderstorm Warning | FSD | 64 min |
| Jul 29, 2:16 PM CDT | Heat Advisory | FSD | 21 hr |
| Jul 29, 3:25 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 29, 4:26 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 29, 6:09 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jul 29, 7:44 PM CDT | Severe Thunderstorm Warning | FSD | 46 min |
| Jul 29, 9:19 PM CDT | Severe Thunderstorm Warning | FSD | 41 min |
| Jul 30, 3:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 30, 4:29 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 31, 5:18 AM CDT | Dense Fog Advisory | FSD | 4 hr |
| Jul 31, 6:36 PM CDT | Severe Thunderstorm Warning | FSD | 24 min |
| Jul 31, 6:57 PM CDT | Severe Thunderstorm Warning | FSD | 48 min |
| Jul 31, 7:24 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 3, 2:57 AM CDT | Heat Advisory | FSD | 17 hr |
| Aug 18, 2:23 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 18, 4:13 AM CDT | Severe Thunderstorm Warning | FSD | 77 min |
| Aug 18, 4:34 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 18, 5:50 AM CDT | Mesoscale Discussion | SPC | 115 min |
| Aug 23, 1:59 PM CDT | Heat Advisory | FSD | 54 hr |
| Aug 25, 3:15 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 25, 5:17 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 25, 6:10 PM CDT | Severe Thunderstorm Warning | FSD | 35 min |
| Aug 25, 6:41 PM CDT | Severe Thunderstorm Warning | FSD | 64 min |
| Aug 25, 7:30 PM CDT | Severe Thunderstorm Warning | FSD | 45 min |
| Aug 25, 7:50 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Aug 26, 2:37 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Aug 26, 3:11 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 26, 7:01 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Aug 26, 9:28 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Aug 26, 10:55 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 11, 2:25 PM CDT | Wind Advisory | FSD | 31 hr |
| Sep 29, 1:55 AM CDT | Fire Weather Watch | FSD | 14 hr |
| Sep 29, 3:28 PM CDT | Red Flag Warning | FSD | 29 hr |
| Oct 2, 9:38 AM CDT | Red Flag Warning | FSD | 9 hr |
| Oct 3, 1:38 PM CDT | Fire Weather Watch | FSD | 25 hr |
| Oct 4, 11:05 AM CDT | Red Flag Warning | FSD | 9 hr |
| Oct 4, 2:41 PM CDT | Red Flag Warning | FSD | 29 hr |
| Oct 13, 3:04 AM CDT | Frost Advisory | FSD | 11 hr |
| Oct 13, 2:32 PM CDT | Freeze Warning | FSD | 18 hr |
| Oct 14, 1:52 PM CDT | Freeze Warning | FSD | 19 hr |
| Oct 15, 2:39 AM CDT | Fire Weather Watch | FSD | 12 hr |
| Oct 15, 2:37 PM CDT | Fire Weather Watch | FSD | 23 hr |
| Oct 15, 2:37 PM CDT | Red Flag Warning | FSD | 28 hr |
| Oct 16, 2:06 PM CDT | Red Flag Warning | FSD | 29 hr |
| Nov 10, 3:33 AM CST | Dense Fog Advisory | FSD | 5 hr |
| Nov 18, 2:08 PM CST | Wind Advisory | FSD | 58 hr |
| Nov 19, 2:05 PM CST | High Wind Warning | FSD | 28 hr |
| Dec 3, 1:03 PM CST | Wind Advisory | FSD | 32 hr |
| Dec 8, 9:01 PM CST | Wind Advisory | FSD | 17 hr |
| Dec 14, 2:33 PM CST | Dense Fog Advisory | FSD | 20 hr |
| Dec 16, 8:41 AM CST | Wind Advisory | FSD | 6 hr |
| Dec 18, 2:50 PM CST | High Wind Warning | FSD | 27 hr |
| Dec 23, 2:20 PM CST | Dense Fog Advisory | FSD | 70 hr |
| Dec 29, 1:46 PM CST | Winter Weather Advisory | FSD | 37 hr |
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 | 12 |
| Severe Thunderstorm Watch | 13 |
| Mesoscale Discussion | 21 |
| Flooding | |
| Flash Flood Warning | 2 |
| Flood Watch | 1 |
| Winter | |
| Blizzard Warning | 2 |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 6 |
| Heat | |
| Heat Advisory | 6 |
| Cold | |
| Freeze Warning | 2 |
| Wind Chill Warning | 1 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 2 |
| Wind Advisory | 12 |
| Fire | |
| Red Flag Warning | 11 |
| Fire Weather Watch | 8 |
| Fog and smoke | |
| Dense Fog Advisory | 13 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20232025
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.