Alert archive / North Dakota / Grand Forks County
Weather alerts in Grand Forks County, North Dakota, 2021
111 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Grand Forks County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 111
- Warnings
- 41
- Watches
- 16
- Advisories
- 34
- Busiest month
- August24 alerts
- Busiest day
- August 10, 20218 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
2 of 3 tornado warnings covering Grand Forks County in 2021 had a tornado report inside them; 1 of 2 tornado reports fell inside a warning, on average 22 minutes after it went out.
Grand Forks County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 3 | 2 | 33% | 2 | 50% | 22 min |
| Severe thunderstorm warnings | 19 | 17 | 11% | 30 | 83% | 35 min |
| Flash flood warnings | 1 | 0 | 100% | 2 | 0% |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Forks, ND: tornado warnings | 15 | 8 | 47% | 27 | 52% | 5 min |
| NWS Grand Forks, ND: severe thunderstorm warnings | 128 | 111 | 13% | 412 | 82% | 26 min |
| NWS Grand Forks, ND: flash flood warnings | 1 | 0 | 100% | 2 | 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 |
|---|---|---|---|
| Jan 1, 6:36 PM CST | Dense Fog Advisory | FGF | 16 hr |
| Jan 7, 9:03 AM CST | Dense Fog Advisory | FGF | 26 hr |
| Jan 8, 11:03 AM CST | Dense Fog Advisory | FGF | 25 hr |
| Jan 9, 8:59 PM CST | Dense Fog Advisory | FGF | 14 hr |
| Jan 13, 1:00 PM CST | Winter Weather Advisory | FGF | 53 hr |
| Jan 15, 12:13 PM CST | Winter Weather Advisory | FGF | 6 hr |
| Jan 20, 3:30 AM CST | Wind Advisory | FGF | 16 hr |
| Jan 23, 3:00 PM CST | Wind Chill Advisory | FGF | 21 hr |
| Jan 25, 2:20 PM CST | Wind Chill Advisory | FGF | 46 hr |
| Jan 29, 2:55 PM CST | Winter Weather Advisory | FGF | 30 hr |
| Feb 4, 4:44 AM CST | Wind Chill Watch | FGF | 23 hr |
| Feb 5, 3:16 AM CST | Wind Chill Warning | FGF | 10 days |
| Feb 15, 12:04 PM CST | Wind Chill Advisory | FGF | 46 hr |
| Feb 22, 3:29 PM CST | Winter Weather Advisory | FGF | 33 hr |
| Mar 26, 2:51 PM CDT | Fire Weather Watch | FGF | 48 hr |
| Mar 28, 3:13 PM CDT | Red Flag Warning | FGF | 32 hr |
| Mar 28, 3:16 PM CDT | Wind Advisory | FGF | 55 hr |
| Mar 31, 3:20 AM CDT | Fire Weather Watch | FGF | 11 hr |
| Mar 31, 2:32 PM CDT | Red Flag Warning | FGF | 31 hr |
| Apr 2, 3:35 AM CDT | Red Flag Warning | FGF | 16 hr |
| Apr 12, 3:28 PM CDT | Winter Weather Advisory | FGF | 26 hr |
| Apr 21, 11:22 AM CDT | Fire Weather Watch | FGF | 17 hr |
| Apr 22, 3:54 AM CDT | Red Flag Warning | FGF | 16 hr |
| May 1, 3:51 AM CDT | Red Flag Warning | FGF | 16 hr |
| May 5, 2:55 PM CDT | Fire Weather Watch | FGF | 12 hr |
| May 6, 3:15 AM CDT | Red Flag Warning | FGF | 19 hr |
| May 19, 5:03 PM CDT | Mesoscale Discussion | SPC | 117 min |
| May 20, 10:29 PM CDT | Dense Fog Advisory | FGF | 12 hr |
| May 25, 3:05 AM CDT | Wind Advisory | FGF | 18 hr |
| May 26, 3:50 AM CDT | Frost Advisory | FGF | 28 hr |
| May 27, 3:56 AM CDT | Freeze Watch | FGF | 11 hr |
| May 27, 2:33 PM CDT | Freeze Warning | FGF | 17 hr |
| Jun 3, 3:34 AM CDT | Fire Weather Watch | FGF | 36 hr |
| Jun 3, 3:02 PM CDT | Red Flag Warning | FGF | 30 hr |
| Jun 4, 4:32 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 4, 7:24 PM CDT | Special Weather Statement | FGF | 36 min |
| Jun 4, 7:49 PM CDT | Severe Thunderstorm Warning | FGF | 41 min |
| Jun 5, 2:49 PM CDT | Fire Weather Watch | FGF | 14 hr |
| Jun 6, 1:39 AM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Jun 6, 2:39 AM CDT | Severe Thunderstorm Warning | FGF | 51 min |
| Jun 6, 4:33 AM CDT | Red Flag Warning | FGF | 16 hr |
| Jun 7, 5:22 PM CDT | Severe Thunderstorm Warning | FGF | 38 min |
| Jun 7, 5:45 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 11, 12:52 AM CDT | Mesoscale Discussion | SPC | 53 min |
| Jun 11, 1:58 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 11, 4:19 AM CDT | Severe Thunderstorm Warning | FGF | 56 min |
| Jun 11, 4:37 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 11, 5:07 AM CDT | Severe Thunderstorm Warning | FGF | 68 min |
| Jun 23, 5:16 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Jul 3, 6:57 PM CDT | Severe Thunderstorm Warning | FGF | 48 min |
| Jul 3, 7:31 PM CDT | Severe Thunderstorm Warning | FGF | 59 min |
| Jul 3, 9:21 PM CDT | Severe Thunderstorm Warning | FGF | 24 min |
| Jul 15, 3:36 PM CDT | Special Weather Statement | FGF | 24 min |
| Jul 15, 4:42 PM CDT | Areal Flood Advisory | FGF | 2 hr |
| Jul 15, 6:49 PM CDT | Flash Flood Warning | FGF | 4 hr |
| Jul 15, 10:44 PM CDT | Areal Flood Warning | FGF | 11 hr |
| Jul 19, 11:28 AM CDT | Severe Thunderstorm Warning | FGF | 62 min |
| Jul 19, 12:11 PM CDT | Severe Thunderstorm Warning | FGF | 64 min |
| Jul 19, 12:21 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jul 19, 1:02 PM CDT | Special Weather Statement | FGF | 58 min |
| Jul 19, 1:32 PM CDT | Severe Thunderstorm Warning | FGF | 58 min |
| Jul 19, 7:04 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 19, 8:31 PM CDT | Special Weather Statement | FGF | 59 min |
| Jul 20, 3:08 AM CDT | Dense Fog Advisory | FGF | 7 hr |
| Aug 9, 2:56 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 9, 4:01 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 9, 6:34 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Aug 9, 8:08 PM CDT | Severe Thunderstorm Warning | FGF | 27 min |
| Aug 9, 9:09 PM CDT | Severe Thunderstorm Warning | FGF | 66 min |
| Aug 9, 9:20 PM CDT | Tornado Warning | FGF | 40 min |
| Aug 9, 9:42 PM CDT | Tornado Warning | FGF | 48 min |
| Aug 9, 9:52 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Aug 9, 9:54 PM CDT | Severe Thunderstorm Warning | FGF | 66 min |
| Aug 9, 10:30 PM CDT | Severe Thunderstorm Warning | FGF | 30 min |
| Aug 9, 10:42 PM CDT | Severe Thunderstorm Warning | FGF | 63 min |
| Aug 20, 9:47 AM CDT | Special Weather Statement | FGF | 28 min |
| Aug 20, 11:04 AM CDT | Areal Flood Advisory | FGF | 4 hr |
| Aug 20, 1:41 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 20, 2:24 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 20, 5:13 PM CDT | Severe Thunderstorm Warning | FGF | 39 min |
| Aug 20, 7:04 PM CDT | High Wind Warning | FGF | 4 hr |
| Aug 22, 10:01 AM CDT | Wind Advisory | FGF | 10 hr |
| Aug 22, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 22, 5:59 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Aug 22, 7:40 PM CDT | Severe Thunderstorm Warning | FGF | 23 min |
| Aug 22, 7:46 PM CDT | Tornado Warning | FGF | 18 min |
| Aug 28, 12:41 AM CDT | Dense Fog Advisory | FGF | 11 hr |
| Aug 28, 8:48 AM CDT | Special Weather Statement | FGF | 57 min |
| Sep 15, 10:47 PM CDT | Severe Thunderstorm Warning | FGF | 43 min |
| Oct 15, 11:45 AM CDT | Freeze Warning | FGF | 21 hr |
| Oct 26, 3:37 AM CDT | Wind Advisory | FGF | 14 hr |
| Oct 28, 1:41 AM CDT | Dense Fog Advisory | FGF | 7 hr |
| Nov 10, 3:06 PM CST | Winter Weather Advisory | FGF | 45 hr |
| Nov 13, 6:59 AM CST | Winter Weather Advisory | FGF | 16 hr |
| Nov 15, 9:19 AM CST | Winter Weather Advisory | FGF | 5 hr |
| Nov 16, 2:59 AM CST | Wind Advisory | FGF | 43 hr |
| Dec 3, 3:22 AM CST | Winter Storm Watch | FGF | 35 hr |
| Dec 4, 3:52 AM CST | Winter Storm Warning | FGF | 47 hr |
| Dec 5, 6:04 PM CST | Blizzard Warning | FGF | 9 hr |
| Dec 5, 9:46 PM CST | Wind Chill Advisory | FGF | 15 hr |
| Dec 15, 3:25 AM CST | Winter Weather Advisory | FGF | 31 hr |
| Dec 15, 6:43 AM CST | Dense Fog Advisory | FGF | 13 hr |
| Dec 25, 3:21 AM CST | Winter Storm Watch | FGF | 24 hr |
| Dec 26, 3:22 AM CST | Winter Storm Warning | FGF | 36 hr |
| Dec 26, 4:44 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 26, 9:07 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 27, 3:41 PM CST | Wind Chill Advisory | FGF | 26 hr |
| Dec 28, 6:53 AM CST | Winter Weather Advisory | FGF | 16 hr |
| Dec 28, 3:21 PM CST | Wind Chill Warning | FGF | 40 hr |
| Dec 28, 3:21 PM CST | Wind Chill Advisory | FGF | 45 hr |
| Dec 30, 3:08 PM CST | Wind Chill Warning | FGF | 67 hr |
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 archive20202022
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.