Alert archive / North Dakota / Sioux County
Weather alerts in Sioux County, North Dakota, 2015
83 weather alerts in 2015, 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 2015. Tap one for its archive.
- Alerts
- 83
- Warnings
- 27
- Watches
- 21
- Advisories
- 4
- Busiest month
- June23 alerts
- Busiest day
- June 22, 20157 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, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 14 | 8 | 43% | 4 | 75% | 27 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Bismarck, ND: tornado warnings | 15 | 1 | 93% | 7 | 14% | 4 min |
| NWS Bismarck, ND: severe thunderstorm warnings | 183 | 122 | 33% | 264 | 77% | 26 min |
| NWS Bismarck, ND: flash flood warnings | 4 | 2 | 50% | 2 | 100% | 26 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 |
|---|---|---|---|
| Feb 9, 10:48 PM CST | Mesoscale Discussion | SPC | 3 hr |
| Mar 13, 2:48 PM CDT | Fire Weather Watch | BIS | 13 hr |
| Mar 14, 3:55 AM CDT | Fire Weather Watch | BIS | 24 hr |
| Mar 14, 3:55 AM CDT | Red Flag Warning | BIS | 16 hr |
| Mar 28, 7:16 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Mar 28, 7:27 PM CDT | Severe Thunderstorm Warning | BIS | 48 min |
| Mar 28, 7:58 PM CDT | Severe Thunderstorm Warning | BIS | 47 min |
| Mar 28, 8:40 PM CDT | Severe Thunderstorm Warning | BIS | 50 min |
| Mar 30, 3:31 PM CDT | Fire Weather Watch | BIS | 12 hr |
| Mar 31, 3:56 AM CDT | Fire Weather Watch | BIS | 11 hr |
| Mar 31, 3:56 AM CDT | Red Flag Warning | BIS | 17 hr |
| Mar 31, 3:25 PM CDT | Red Flag Warning | BIS | 30 hr |
| Apr 1, 3:40 PM CDT | Fire Weather Watch | BIS | 12 hr |
| Apr 2, 3:39 AM CDT | Red Flag Warning | BIS | 15 hr |
| Apr 11, 4:13 AM CDT | Red Flag Warning | BIS | 15 hr |
| Apr 11, 3:47 PM CDT | Fire Weather Watch | BIS | 12 hr |
| Apr 12, 3:58 AM CDT | Red Flag Warning | BIS | 18 hr |
| Apr 12, 12:59 PM CDT | Fire Weather Watch | BIS | 15 hr |
| Apr 13, 3:59 AM CDT | Fire Weather Watch | BIS | 17 hr |
| Apr 13, 3:59 AM CDT | Red Flag Warning | BIS | 16 hr |
| Apr 13, 8:58 PM CDT | Red Flag Warning | BIS | 25 hr |
| Apr 15, 3:47 AM CDT | Red Flag Warning | BIS | 16 hr |
| Apr 19, 2:33 PM CDT | Red Flag Warning | BIS | 31 hr |
| May 1, 2:51 PM CDT | Fire Weather Watch | BIS | 12 hr |
| May 2, 3:10 AM CDT | Red Flag Warning | BIS | 17 hr |
| May 13, 12:33 PM CDT | Special Weather Statement | BIS | 27 min |
| May 16, 6:30 PM CDT | Areal Flood Advisory | BIS | 3 hr |
| Jun 2, 2:28 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jun 2, 2:43 PM CDT | Severe Thunderstorm Warning | BIS | 62 min |
| Jun 2, 2:46 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 2, 5:44 PM CDT | Severe Thunderstorm Warning | BIS | 61 min |
| Jun 2, 6:22 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Jun 2, 6:39 PM CDT | Severe Thunderstorm Warning | BIS | 66 min |
| Jun 14, 2:59 AM CDT | Areal Flood Advisory | BIS | 6 hr |
| Jun 14, 3:19 AM CDT | Special Weather Statement | BIS | 26 min |
| Jun 14, 3:50 AM CDT | Special Weather Statement | BIS | 25 min |
| Jun 19, 3:01 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 19, 5:48 PM CDT | Mesoscale Discussion | SPC | 57 min |
| Jun 19, 9:15 PM CDT | Severe Thunderstorm Warning | BIS | 30 min |
| Jun 21, 3:23 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 21, 5:24 PM CDT | Mesoscale Discussion | SPC | 66 min |
| Jun 21, 8:32 PM CDT | Severe Thunderstorm Warning | BIS | 58 min |
| Jun 21, 8:32 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Jun 21, 9:11 PM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Jun 21, 10:41 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 21, 11:25 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jun 22, 12:37 AM CDT | Special Weather Statement | BIS | 23 min |
| Jun 22, 1:03 AM CDT | Special Weather Statement | BIS | 42 min |
| Jun 23, 7:57 PM CDT | Severe Thunderstorm Warning | BIS | 46 min |
| Jun 30, 5:29 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 30, 11:17 PM CDT | Severe Thunderstorm Warning | BIS | 58 min |
| Jul 4, 6:49 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 11, 5:40 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 11, 9:04 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jul 15, 5:50 PM CDT | Severe Thunderstorm Warning | BIS | 55 min |
| Jul 15, 6:03 PM CDT | Special Weather Statement | BIS | 27 min |
| Jul 15, 7:06 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 15, 8:58 PM CDT | Special Weather Statement | BIS | 32 min |
| Jul 15, 9:31 PM CDT | Special Weather Statement | BIS | 29 min |
| Jul 15, 9:59 PM CDT | Special Weather Statement | BIS | 31 min |
| Jul 16, 2:03 AM CDT | Areal Flood Advisory | BIS | 8 hr |
| Jul 16, 5:52 AM CDT | Areal Flood Advisory | BIS | 6 hr |
| Jul 23, 1:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 23, 3:58 PM CDT | Severe Thunderstorm Watch | SPC | 11 hr |
| Jul 23, 6:21 PM CDT | Mesoscale Discussion | SPC | 24 min |
| Jul 26, 6:23 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Jul 26, 9:53 PM CDT | Special Weather Statement | BIS | 37 min |
| Jul 27, 6:51 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 27, 7:31 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 27, 9:19 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 27, 9:39 PM CDT | Severe Thunderstorm Warning | BIS | 51 min |
| Jul 27, 10:27 PM CDT | Severe Thunderstorm Warning | BIS | 48 min |
| Aug 5, 8:39 AM CDT | Special Weather Statement | BIS | 21 min |
| Aug 5, 9:18 AM CDT | Special Weather Statement | BIS | 27 min |
| Aug 28, 2:55 PM CDT | Fire Weather Watch | BIS | 13 hr |
| Sep 3, 5:00 PM CDT | Special Weather Statement | BIS | 45 min |
| Sep 3, 5:53 PM CDT | Special Weather Statement | BIS | 37 min |
| Sep 3, 6:29 PM CDT | Special Weather Statement | BIS | 61 min |
| Sep 5, 7:00 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Oct 10, 2:19 PM CDT | Fire Weather Watch | BIS | 14 hr |
| Oct 11, 3:49 AM CDT | Red Flag Warning | BIS | 17 hr |
| Nov 16, 2:46 PM CST | Fire Weather Watch | BIS | 30 hr |
| Nov 17, 9:14 PM CST | Red Flag Warning | BIS | 23 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 | 14 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 3 |
| Mesoscale Discussion | 16 |
| Special Weather Statement | 15 |
| Flooding | |
| Areal Flood Advisory | 4 |
| Fire | |
| Red Flag Warning | 13 |
| Fire Weather Watch | 12 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20142016
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.