Alert archive / North Dakota / Williams County
Weather alerts in Williams County, North Dakota, 2018
137 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Williams County and its neighbors
Each county as a circle sized by its count in 2018. Tap one for its archive.
- Alerts
- 137
- Warnings
- 38
- Watches
- 16
- Advisories
- 49
- Busiest month
- July29 alerts
- Busiest day
- July 10, 201810 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Williams County, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 23 | 17 | 26% | 23 | 96% | 33 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Bismarck, ND: tornado warnings | 24 | 5 | 79% | 22 | 64% | 9 min |
| NWS Bismarck, ND: severe thunderstorm warnings | 275 | 164 | 40% | 315 | 90% | 28 min |
| NWS Bismarck, ND: flash flood warnings | 7 | 4 | 43% | 7 | 71% | 119 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 1, 11:59 AM CST | Wind Chill Advisory | BIS | 22 hr |
| Jan 9, 4:10 AM CST | Winter Weather Advisory | BIS | 53 hr |
| Jan 11, 12:01 AM CST | Wind Chill Advisory | BIS | 60 hr |
| Jan 12, 3:24 AM CST | Wind Chill Warning | BIS | 32 hr |
| Jan 14, 2:42 AM CST | Wind Chill Advisory | BIS | 57 hr |
| Jan 18, 2:10 PM CST | Winter Weather Advisory | BIS | 18 hr |
| Jan 29, 2:26 PM CST | Wind Advisory | BIS | 29 hr |
| Jan 31, 2:34 PM CST | Wind Chill Advisory | BIS | 21 hr |
| Feb 3, 3:18 AM CST | Wind Chill Advisory | BIS | 33 hr |
| Feb 3, 9:09 PM CST | Wind Chill Advisory | BIS | 15 hr |
| Feb 4, 3:03 PM CST | Wind Chill Advisory | BIS | 20 hr |
| Feb 5, 3:52 AM CST | Wind Chill Advisory | BIS | 29 hr |
| Feb 6, 2:05 PM CST | Wind Chill Advisory | BIS | 19 hr |
| Feb 8, 2:45 PM CST | Wind Chill Advisory | BIS | 21 hr |
| Feb 9, 2:59 PM CST | Wind Chill Advisory | BIS | 21 hr |
| Feb 11, 3:43 PM CST | Wind Chill Advisory | BIS | 20 hr |
| Feb 17, 2:39 PM CST | Winter Weather Advisory | BIS | 21 hr |
| Feb 20, 3:07 PM CST | Wind Chill Advisory | BIS | 19 hr |
| Mar 2, 4:22 AM CST | Winter Storm Watch | BIS | 59 hr |
| Mar 3, 3:41 PM CST | Dense Fog Advisory | BIS | 20 hr |
| Mar 3, 4:07 PM CST | Winter Storm Warning | BIS | 65 hr |
| Mar 4, 3:00 PM CST | Special Weather Statement | BIS | 45 min |
| Mar 4, 3:47 PM CST | Mesoscale Discussion | SPC | 3 hr |
| Mar 6, 3:11 AM CST | Winter Weather Advisory | BIS | 6 hr |
| Mar 12, 11:57 PM CDT | Dense Fog Advisory | BIS | 10 hr |
| Mar 14, 6:40 AM CDT | Dense Fog Advisory | BIS | 5 hr |
| Mar 22, 12:23 AM CDT | Dense Fog Advisory | BIS | 14 hr |
| Mar 22, 3:51 AM CDT | Winter Storm Warning | BIS | 43 hr |
| Mar 22, 3:51 AM CDT | Winter Weather Advisory | BIS | 55 hr |
| Mar 23, 2:45 PM CDT | River Flood Watch | BIS | 24 hr |
| Mar 24, 1:03 AM CDT | Dense Fog Advisory | BIS | 10 hr |
| Mar 24, 1:30 PM CDT | River Flood Warning | BIS | 4 days |
| Mar 26, 6:00 AM CDT | Dense Fog Advisory | BIS | 7 hr |
| Mar 29, 4:08 AM CDT | Winter Storm Watch | BIS | 24 hr |
| Mar 29, 10:08 AM CDT | River Flood Warning | BIS | 8 days |
| Mar 30, 4:01 AM CDT | Winter Storm Warning | BIS | 24 hr |
| Mar 30, 3:03 PM CDT | Mesoscale Discussion | SPC | 5 hr |
| Mar 30, 9:40 PM CDT | Wind Chill Advisory | BIS | 13 hr |
| Apr 6, 3:18 PM CDT | Winter Weather Advisory | BIS | 52 hr |
| Apr 19, 6:46 AM CDT | Dense Fog Advisory | BIS | 4 hr |
| Apr 19, 9:13 AM CDT | River Flood Warning | BIS | 10 hr |
| Apr 20, 8:28 AM CDT | River Flood Warning | BIS | 12 hr |
| Apr 21, 7:04 AM CDT | River Flood Warning | BIS | 33 hr |
| Apr 26, 9:15 AM CDT | Red Flag Warning | BIS | 10 hr |
| Apr 28, 3:40 AM CDT | Red Flag Warning | BIS | 17 hr |
| Apr 29, 10:33 PM CDT | Special Weather Statement | BIS | 27 min |
| May 9, 2:41 PM CDT | River Flood Warning | BIS | 83 days |
| May 16, 11:58 PM CDT | Special Weather Statement | BIS | 47 min |
| May 17, 12:17 AM CDT | Special Weather Statement | BIS | 43 min |
| May 17, 1:55 AM CDT | Special Weather Statement | BIS | 50 min |
| May 18, 2:29 PM CDT | Frost Advisory | BIS | 19 hr |
| May 23, 11:09 PM CDT | Special Weather Statement | BIS | 66 min |
| May 27, 12:11 AM CDT | Special Weather Statement | BIS | 34 min |
| May 30, 10:02 PM CDT | Severe Thunderstorm Warning | BIS | 58 min |
| May 30, 11:07 PM CDT | Special Weather Statement | BIS | 38 min |
| Jun 1, 2:13 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 1, 3:30 PM CDT | Tornado Watch | SPC | 6 hr |
| Jun 1, 5:25 PM CDT | Severe Thunderstorm Warning | BIS | 35 min |
| Jun 1, 5:29 PM CDT | Severe Thunderstorm Warning | BIS | 61 min |
| Jun 1, 6:02 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Jun 2, 3:10 AM CDT | Wind Advisory | BIS | 18 hr |
| Jun 5, 12:00 AM CDT | Special Weather Statement | BIS | 45 min |
| Jun 7, 7:09 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 7, 10:04 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jun 10, 3:37 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 14, 10:56 AM CDT | Severe Thunderstorm Warning | BIS | 49 min |
| Jun 14, 11:44 AM CDT | Severe Thunderstorm Warning | BIS | 46 min |
| Jun 14, 12:28 PM CDT | Severe Thunderstorm Warning | BIS | 47 min |
| Jun 14, 2:54 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jun 14, 3:40 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 14, 6:41 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Jun 23, 2:07 PM CDT | Special Weather Statement | BIS | 38 min |
| Jun 23, 2:53 PM CDT | Special Weather Statement | BIS | 22 min |
| Jun 28, 2:01 PM CDT | Flash Flood Watch | BIS | 14 hr |
| Jun 28, 3:16 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 28, 5:04 PM CDT | Severe Thunderstorm Warning | BIS | 23 min |
| Jun 28, 6:59 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 28, 8:47 PM CDT | Severe Thunderstorm Warning | BIS | 58 min |
| Jun 28, 9:06 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 28, 9:46 PM CDT | Severe Thunderstorm Warning | BIS | 59 min |
| Jun 28, 10:21 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 28, 10:41 PM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Jul 3, 9:13 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 3, 9:39 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 3, 11:52 PM CDT | Special Weather Statement | BIS | 53 min |
| Jul 4, 12:42 AM CDT | Special Weather Statement | BIS | 48 min |
| Jul 9, 5:48 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jul 9, 7:01 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 9, 7:30 PM CDT | Special Weather Statement | BIS | 45 min |
| Jul 9, 8:38 PM CDT | Severe Thunderstorm Warning | BIS | 67 min |
| Jul 9, 8:59 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jul 9, 9:42 PM CDT | Severe Thunderstorm Warning | BIS | 63 min |
| Jul 9, 10:04 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Jul 9, 10:24 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jul 9, 10:41 PM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Jul 9, 11:42 PM CDT | Severe Thunderstorm Warning | BIS | 63 min |
| Jul 10, 12:18 AM CDT | Areal Flood Advisory | BIS | 3 hr |
| Jul 10, 7:32 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Jul 10, 8:50 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 10, 9:19 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Jul 10, 10:09 PM CDT | Severe Thunderstorm Warning | BIS | 66 min |
| Jul 18, 2:21 PM CDT | Severe Thunderstorm Warning | BIS | 54 min |
| Jul 18, 2:44 PM CDT | Severe Thunderstorm Warning | BIS | 31 min |
| Jul 21, 12:53 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 21, 3:24 PM CDT | Special Weather Statement | BIS | 36 min |
| Jul 21, 3:37 PM CDT | Severe Thunderstorm Warning | BIS | 27 min |
| Jul 21, 4:55 PM CDT | Severe Thunderstorm Warning | BIS | 65 min |
| Jul 21, 5:11 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 21, 5:56 PM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Jul 21, 6:18 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 21, 6:56 PM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Aug 10, 3:26 PM CDT | Fire Weather Watch | BIS | 23 hr |
| Aug 11, 2:18 PM CDT | Red Flag Warning | BIS | 31 hr |
| Aug 12, 3:13 AM CDT | Heat Advisory | BIS | 16 hr |
| Aug 26, 3:52 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Sep 3, 5:00 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Sep 3, 5:44 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 4, 2:50 PM CDT | Frost Advisory | BIS | 18 hr |
| Sep 20, 2:32 PM CDT | Frost Advisory | BIS | 18 hr |
| Sep 25, 2:06 PM CDT | Frost Advisory | BIS | 18 hr |
| Sep 27, 2:55 AM CDT | Freeze Watch | BIS | 12 hr |
| Sep 27, 2:31 PM CDT | Freeze Warning | BIS | 19 hr |
| Sep 28, 3:09 PM CDT | Freeze Warning | BIS | 18 hr |
| Oct 2, 8:51 PM CDT | Dense Fog Advisory | BIS | 5 hr |
| Oct 4, 3:20 AM CDT | Winter Weather Advisory | BIS | 39 hr |
| Nov 1, 3:10 PM CDT | Winter Weather Advisory | BIS | 42 hr |
| Nov 5, 9:17 PM CST | Wind Advisory | BIS | 21 hr |
| Nov 15, 3:01 PM CST | Winter Weather Advisory | BIS | 29 hr |
| Nov 20, 8:52 PM CST | Dense Fog Advisory | BIS | 14 hr |
| Nov 21, 2:04 PM CST | Dense Fog Advisory | BIS | 22 hr |
| Nov 27, 3:13 AM CST | Winter Weather Advisory | BIS | 45 hr |
| Nov 29, 3:36 AM CST | Dense Fog Advisory | BIS | 9 hr |
| Nov 29, 6:31 PM CST | Dense Fog Advisory | BIS | 20 hr |
| Nov 30, 4:07 AM CST | Winter Weather Advisory | BIS | 38 hr |
| Nov 30, 2:56 PM CST | Dense Fog Advisory | BIS | 43 hr |
| Dec 1, 2:59 PM CST | Dense Fog Advisory | BIS | 19 hr |
| Dec 30, 2:58 PM CST | Wind Chill Advisory | BIS | 43 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 | 23 |
| Severe Thunderstorm Watch | 7 |
| Tornado Watch | 3 |
| Mesoscale Discussion | 19 |
| Special Weather Statement | 15 |
| Flooding | |
| River Flood Warning | 6 |
| Flash Flood Watch | 1 |
| River Flood Watch | 1 |
| Areal Flood Advisory | 1 |
| Winter | |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 11 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 2 |
| Wind Chill Warning | 1 |
| Freeze Watch | 1 |
| Frost Advisory | 4 |
| Wind Chill Advisory | 15 |
| Wind and dust | |
| Wind Advisory | 3 |
| Fire | |
| Red Flag Warning | 3 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 14 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20172019
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.