Alert archive / North Dakota / Sioux County
Weather alerts in Sioux County, North Dakota, 2023
46 weather alerts in 2023, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Sioux County and its neighbors
Each county as a circle sized by its count in 2023. Tap one for its archive.
- Alerts
- 46
- Warnings
- 20
- Watches
- 4
- Advisories
- 2
- Busiest month
- June12 alerts
- Busiest day
- June 20, 20235 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Sioux County, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 15 | 12 | 20% | 12 | 100% | 33 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Bismarck, ND: tornado warnings | 4 | 1 | 75% | 4 | 25% | 11 min |
| NWS Bismarck, ND: severe thunderstorm warnings | 132 | 89 | 33% | 203 | 86% | 26 min |
| NWS Bismarck, ND: flash flood warnings | 1 | 0 | 100% | 0 |
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 |
|---|---|---|---|
| Feb 28, 12:18 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Apr 10, 8:33 PM CDT | River Flood Warning | BIS | 8 days |
| Apr 12, 10:57 AM CDT | Areal Flood Warning | BIS | 28 hr |
| Apr 13, 2:50 PM CDT | Areal Flood Warning | BIS | 22 hr |
| Apr 14, 12:53 PM CDT | Areal Flood Warning | BIS | 6 days |
| Apr 28, 2:38 PM CDT | Fire Weather Watch | BIS | 13 hr |
| Apr 29, 3:59 AM CDT | Red Flag Warning | BIS | 17 hr |
| May 23, 6:19 PM CDT | Special Weather Statement | BIS | 26 min |
| Jun 2, 2:15 PM CDT | Special Weather Statement | BIS | 30 min |
| Jun 8, 1:49 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 20, 3:14 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 20, 4:52 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 20, 5:22 PM CDT | Special Weather Statement | BIS | 23 min |
| Jun 20, 5:38 PM CDT | Severe Thunderstorm Warning | BIS | 52 min |
| Jun 20, 6:30 PM CDT | Severe Thunderstorm Warning | BIS | 35 min |
| Jun 20, 8:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 21, 8:34 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Jun 21, 9:24 PM CDT | Severe Thunderstorm Warning | BIS | 66 min |
| Jun 21, 10:17 PM CDT | Severe Thunderstorm Warning | BIS | 31 min |
| Jun 24, 2:08 PM CDT | Areal Flood Advisory | BIS | 6 hr |
| Jul 11, 7:54 PM CDT | Severe Thunderstorm Warning | BIS | 66 min |
| Jul 18, 5:42 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 26, 4:31 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Jul 26, 4:39 PM CDT | Special Weather Statement | BIS | 36 min |
| Jul 26, 4:53 PM CDT | Severe Thunderstorm Warning | BIS | 42 min |
| Jul 26, 5:28 PM CDT | Special Weather Statement | BIS | 32 min |
| Jul 30, 7:56 AM CDT | Severe Thunderstorm Warning | BIS | 49 min |
| Jul 30, 8:52 AM CDT | Severe Thunderstorm Warning | BIS | 53 min |
| Jul 30, 9:02 AM CDT | Severe Thunderstorm Warning | BIS | 73 min |
| Jul 30, 9:21 AM CDT | Areal Flood Advisory | BIS | 111 min |
| Aug 1, 3:12 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 1, 3:38 PM CDT | Severe Thunderstorm Warning | BIS | 41 min |
| Aug 1, 3:52 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 1, 5:44 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Aug 1, 6:05 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Aug 1, 7:55 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Aug 1, 10:24 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Aug 9, 3:59 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 4, 4:52 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Sep 4, 5:25 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 4, 6:34 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Sep 4, 7:05 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Sep 4, 7:21 PM CDT | Severe Thunderstorm Warning | BIS | 54 min |
| Sep 4, 8:06 PM CDT | Severe Thunderstorm Warning | BIS | 54 min |
| Oct 26, 10:21 PM CDT | Mesoscale Discussion | SPC | 6 hr |
| Dec 25, 7:56 PM CST | Mesoscale Discussion | SPC | 5 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 | 15 |
| Severe Thunderstorm Watch | 3 |
| Mesoscale Discussion | 15 |
| Special Weather Statement | 5 |
| Flooding | |
| Areal Flood Warning | 3 |
| River Flood Warning | 1 |
| Areal Flood Advisory | 2 |
| Fire | |
| Red Flag Warning | 1 |
| Fire Weather Watch | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20222024
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.