Alert archive / North Dakota / Cass County
Weather alerts in Cass County, North Dakota, 2017
129 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Cass County and its neighbors
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Alerts
- 129
- Warnings
- 47
- Watches
- 14
- Advisories
- 37
- Busiest month
- July27 alerts
- Busiest day
- June 14, 20178 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
1 of 4 tornado warnings covering Cass County in 2017 had a tornado report inside them.
Cass County, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 1 | 75% | 0 | ||
| Severe thunderstorm warnings | 30 | 28 | 7% | 37 | 89% | 25 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Forks, ND: tornado warnings | 39 | 24 | 38% | 67 | 67% | 15 min |
| NWS Grand Forks, ND: severe thunderstorm warnings | 148 | 137 | 7% | 435 | 76% | 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 |
|---|---|---|---|
| Jan 1, 3:27 PM CST | Winter Weather Advisory | FGF | 45 hr |
| Jan 2, 4:14 AM CST | Winter Storm Warning | FGF | 32 hr |
| Jan 3, 2:18 PM CST | Wind Chill Advisory | FGF | 70 hr |
| Jan 6, 2:54 PM CST | Wind Chill Advisory | FGF | 21 hr |
| Jan 7, 3:30 PM CST | Wind Chill Advisory | FGF | 18 hr |
| Jan 10, 2:55 PM CST | Wind Chill Advisory | FGF | 45 hr |
| Jan 11, 3:33 PM CST | Winter Weather Advisory | FGF | 23 hr |
| Jan 12, 2:49 PM CST | Wind Chill Warning | FGF | 21 hr |
| Jan 19, 1:27 AM CST | Dense Fog Advisory | FGF | 11 hr |
| Jan 21, 5:53 PM CST | Dense Fog Advisory | FGF | 18 hr |
| Jan 30, 4:14 AM CST | Wind Advisory | FGF | 15 hr |
| Jan 31, 9:17 AM CST | Winter Weather Advisory | FGF | 3 hr |
| Feb 7, 2:22 PM CST | Wind Chill Advisory | FGF | 43 hr |
| Feb 8, 3:20 PM CST | Wind Chill Advisory | FGF | 18 hr |
| Feb 20, 11:27 AM CST | River Flood Warning | FGF | 8 days |
| Feb 20, 11:27 AM CST | River Flood Warning | FGF | 68 hr |
| Mar 3, 10:28 AM CST | River Flood Watch | FGF | 3 days |
| Mar 6, 3:33 PM CST | Wind Advisory | FGF | 41 hr |
| Mar 7, 3:40 AM CST | High Wind Warning | FGF | 17 hr |
| Mar 7, 6:14 PM CST | Wind Advisory | FGF | 15 hr |
| Mar 9, 3:34 AM CST | Wind Chill Advisory | FGF | 29 hr |
| Mar 11, 3:19 PM CST | Winter Weather Advisory | FGF | 27 hr |
| Mar 26, 11:49 PM CDT | Dense Fog Advisory | FGF | 14 hr |
| Mar 27, 8:46 PM CDT | Dense Fog Advisory | FGF | 15 hr |
| Apr 13, 3:51 AM CDT | Dense Fog Advisory | FGF | 6 hr |
| Apr 25, 3:25 PM CDT | Winter Weather Advisory | FGF | 39 hr |
| May 28, 2:46 PM CDT | Special Weather Statement | FGF | 59 min |
| May 28, 3:54 PM CDT | Mesoscale Discussion | SPC | 66 min |
| Jun 7, 2:11 PM CDT | Tornado Watch | SPC | 4 hr |
| Jun 9, 3:26 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 9, 4:58 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 9, 7:08 PM CDT | Mesoscale Discussion | SPC | 67 min |
| Jun 9, 9:00 PM CDT | Severe Thunderstorm Warning | FGF | 60 min |
| Jun 9, 9:30 PM CDT | Mesoscale Discussion | SPC | 60 min |
| Jun 9, 10:03 PM CDT | Severe Thunderstorm Warning | FGF | 34 min |
| Jun 9, 10:45 PM CDT | Severe Thunderstorm Warning | FGF | 36 min |
| Jun 9, 11:01 PM CDT | Severe Thunderstorm Warning | FGF | 44 min |
| Jun 9, 11:15 PM CDT | Severe Thunderstorm Warning | FGF | 31 min |
| Jun 13, 4:58 AM CDT | Severe Thunderstorm Warning | FGF | 62 min |
| Jun 13, 5:44 AM CDT | Special Weather Statement | FGF | 46 min |
| Jun 13, 2:32 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 13, 5:43 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 13, 5:56 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 13, 7:11 PM CDT | Severe Thunderstorm Warning | FGF | 49 min |
| Jun 13, 8:11 PM CDT | Severe Thunderstorm Warning | FGF | 49 min |
| Jun 13, 8:14 PM CDT | Tornado Warning | FGF | 31 min |
| Jun 13, 8:34 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jun 13, 8:44 PM CDT | Severe Thunderstorm Warning | FGF | 46 min |
| Jun 13, 8:54 PM CDT | Severe Thunderstorm Warning | FGF | 66 min |
| Jun 13, 9:24 PM CDT | Severe Thunderstorm Warning | FGF | 41 min |
| Jun 13, 9:32 PM CDT | Areal Flood Advisory | FGF | 2 hr |
| Jun 19, 1:42 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 21, 3:35 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 21, 5:08 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 4, 3:33 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 4, 6:03 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 4, 8:17 PM CDT | Severe Thunderstorm Warning | FGF | 25 min |
| Jul 4, 8:41 PM CDT | Severe Thunderstorm Warning | FGF | 19 min |
| Jul 4, 8:58 PM CDT | Severe Thunderstorm Warning | FGF | 47 min |
| Jul 4, 9:21 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jul 4, 10:43 PM CDT | Severe Thunderstorm Warning | FGF | 62 min |
| Jul 4, 11:10 PM CDT | Severe Thunderstorm Warning | FGF | 50 min |
| Jul 5, 5:52 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 5, 10:12 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 6, 12:09 AM CDT | Severe Thunderstorm Warning | FGF | 66 min |
| Jul 6, 12:51 AM CDT | Mesoscale Discussion | SPC | 114 min |
| Jul 6, 1:11 AM CDT | Severe Thunderstorm Warning | FGF | 64 min |
| Jul 11, 3:48 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 11, 4:48 PM CDT | Tornado Watch | SPC | 6 hr |
| Jul 11, 7:19 PM CDT | Tornado Warning | FGF | 41 min |
| Jul 11, 7:59 PM CDT | Tornado Warning | FGF | 46 min |
| Jul 19, 7:01 AM CDT | Mesoscale Discussion | SPC | 119 min |
| Jul 21, 2:20 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 21, 3:07 PM CDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 21, 3:53 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Jul 21, 4:10 PM CDT | Severe Thunderstorm Warning | FGF | 65 min |
| Jul 21, 4:51 PM CDT | Severe Thunderstorm Warning | FGF | 54 min |
| Jul 21, 10:34 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jul 22, 2:18 AM CDT | Special Weather Statement | FGF | 27 min |
| Jul 22, 2:37 AM CDT | Severe Thunderstorm Warning | FGF | 38 min |
| Jul 22, 3:07 AM CDT | Severe Thunderstorm Warning | FGF | 53 min |
| Jul 31, 8:31 PM CDT | Severe Thunderstorm Warning | FGF | 59 min |
| Jul 31, 9:13 PM CDT | Severe Thunderstorm Warning | FGF | 62 min |
| Jul 31, 9:23 PM CDT | Severe Thunderstorm Warning | FGF | 52 min |
| Aug 9, 3:22 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Aug 9, 3:37 PM CDT | Special Weather Statement | FGF | 38 min |
| Aug 9, 4:19 PM CDT | Special Weather Statement | FGF | 41 min |
| Aug 9, 4:29 PM CDT | Severe Thunderstorm Warning | FGF | 31 min |
| Aug 9, 4:56 PM CDT | Severe Thunderstorm Warning | FGF | 49 min |
| Sep 1, 7:43 PM CDT | Severe Thunderstorm Warning | FGF | 47 min |
| Sep 1, 8:01 PM CDT | Tornado Warning | FGF | 29 min |
| Sep 1, 8:28 PM CDT | Special Weather Statement | FGF | 32 min |
| Sep 1, 8:59 PM CDT | Special Weather Statement | FGF | 46 min |
| Sep 1, 9:40 PM CDT | Special Weather Statement | FGF | 50 min |
| Sep 19, 3:37 PM CDT | Tornado Watch | SPC | 8 hr |
| Sep 19, 5:14 PM CDT | Severe Thunderstorm Warning | FGF | 61 min |
| Sep 19, 5:56 PM CDT | Severe Thunderstorm Warning | FGF | 52 min |
| Sep 19, 6:36 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Sep 19, 8:56 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 19, 8:57 PM CDT | Areal Flood Advisory | FGF | 5 hr |
| Oct 8, 3:23 PM CDT | Frost Advisory | FGF | 18 hr |
| Oct 8, 3:23 PM CDT | Freeze Watch | FGF | 12 hr |
| Oct 9, 3:01 AM CDT | Freeze Warning | FGF | 30 hr |
| Oct 17, 2:32 PM CDT | Fire Weather Watch | FGF | 13 hr |
| Oct 18, 3:41 AM CDT | Red Flag Warning | FGF | 15 hr |
| Oct 24, 3:32 PM CDT | Winter Storm Watch | FGF | 37 hr |
| Oct 25, 3:15 PM CDT | High Wind Warning | FGF | 31 hr |
| Oct 26, 10:07 PM CDT | Wind Advisory | FGF | 11 hr |
| Oct 28, 5:46 AM CDT | Dense Fog Advisory | FGF | 2 hr |
| Oct 30, 3:52 AM CDT | Wind Advisory | FGF | 13 hr |
| Nov 13, 9:19 PM CST | Dense Fog Advisory | FGF | 15 hr |
| Nov 20, 10:59 AM CST | Wind Advisory | FGF | 19 hr |
| Nov 28, 3:23 AM CST | Wind Advisory | FGF | 15 hr |
| Nov 29, 3:07 AM CST | Wind Advisory | FGF | 14 hr |
| Nov 29, 10:03 AM CST | Red Flag Warning | FGF | 7 hr |
| Nov 29, 5:03 PM CST | Wind Advisory | FGF | 7 hr |
| Dec 3, 3:54 AM CST | Winter Storm Watch | FGF | 24 hr |
| Dec 3, 3:14 PM CST | Blizzard Warning | FGF | 28 hr |
| Dec 4, 12:11 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 4, 3:54 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 4, 6:18 PM CST | Winter Weather Advisory | FGF | 5 hr |
| Dec 11, 5:41 AM CST | Wind Advisory | FGF | 9 hr |
| Dec 12, 3:02 PM CST | Winter Weather Advisory | FGF | 21 hr |
| Dec 13, 5:08 AM CST | High Wind Warning | FGF | 112 min |
| Dec 19, 2:14 PM CST | Winter Weather Advisory | FGF | 38 hr |
| Dec 24, 10:55 AM CST | Wind Chill Warning | FGF | 49 hr |
| Dec 24, 10:55 AM CST | Wind Chill Advisory | FGF | 3 days |
| Dec 28, 3:42 PM CST | Wind Chill Advisory | FGF | 26 hr |
| Dec 29, 2:37 AM CST | Wind Chill Warning | FGF | 3 days |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20162018
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.