Alert archive / Minnesota / Norman County
Weather alerts in Norman County, Minnesota, 2009
105 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Norman County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 105
- Warnings
- 30
- Watches
- 15
- Advisories
- 40
- Busiest month
- January22 alerts
- Busiest day
- June 27, 20098 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 1 tornado warnings covering Norman County in 2009 had a tornado report inside them.
Norman County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 1 | 0% | 0 | ||
| Severe thunderstorm warnings | 2 | 2 | 0% | 1 | 100% | 8 min |
| Flash flood warnings | 1 | 1 | 0% | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Forks, ND: tornado warnings | 19 | 10 | 47% | 26 | 69% | 31 min |
| NWS Grand Forks, ND: severe thunderstorm warnings | 53 | 41 | 23% | 115 | 60% | 24 min |
| NWS Grand Forks, ND: flash flood warnings | 17 | 7 | 59% | 16 | 94% | 185 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, 3:50 PM CST | Winter Storm Watch | FGF | 24 hr |
| Jan 2, 3:43 PM CST | Winter Storm Warning | FGF | 36 hr |
| Jan 2, 3:43 PM CST | Winter Weather Advisory | FGF | 30 hr |
| Jan 3, 6:29 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 3, 12:34 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 3, 3:09 PM CST | Wind Chill Advisory | FGF | 27 hr |
| Jan 7, 3:54 AM CST | Winter Storm Watch | FGF | 31 hr |
| Jan 10, 2:56 PM CST | Winter Storm Watch | FGF | 24 hr |
| Jan 11, 3:00 PM CST | Winter Weather Advisory | FGF | 24 hr |
| Jan 12, 9:59 AM CST | Wind Chill Advisory | FGF | 14 hr |
| Jan 13, 4:13 AM CST | Wind Chill Advisory | FGF | 31 hr |
| Jan 13, 8:34 PM CST | Wind Chill Warning | FGF | 39 hr |
| Jan 13, 8:34 PM CST | Wind Chill Advisory | FGF | 14 hr |
| Jan 16, 7:39 AM CST | Wind Chill Warning | FGF | 4 hr |
| Jan 16, 10:57 PM CST | Winter Weather Advisory | FGF | 10 hr |
| Jan 22, 5:57 AM CST | Dense Fog Advisory | FGF | 6 hr |
| Jan 22, 3:10 PM CST | Wind Chill Advisory | FGF | 5 days |
| Jan 22, 9:43 PM CST | Winter Weather Advisory | FGF | 8 hr |
| Jan 30, 3:04 PM CST | Blizzard Watch | FGF | 13 hr |
| Jan 31, 4:23 AM CST | High Wind Warning | FGF | 14 hr |
| Jan 31, 4:23 AM CST | Wind Advisory | FGF | 18 hr |
| Jan 31, 11:21 AM CST | Wind Advisory | FGF | 11 hr |
| Feb 1, 4:08 AM CST | Wind Advisory | FGF | 17 hr |
| Feb 1, 9:23 PM CST | Wind Chill Advisory | FGF | 30 hr |
| Feb 7, 3:24 PM CST | Winter Storm Watch | FGF | 24 hr |
| Feb 8, 3:44 PM CST | Ice Storm Warning | FGF | 32 hr |
| Feb 8, 3:44 PM CST | Winter Weather Advisory | FGF | 36 hr |
| Feb 25, 2:49 PM CST | Wind Chill Advisory | FGF | 45 hr |
| Feb 26, 8:42 AM CST | Winter Weather Advisory | FGF | 9 hr |
| Mar 8, 5:13 AM CDT | Blizzard Watch | FGF | 35 hr |
| Mar 9, 4:24 AM CDT | Winter Weather Advisory | FGF | 18 hr |
| Mar 9, 3:56 PM CDT | Blizzard Warning | FGF | 37 hr |
| Mar 10, 9:53 AM CDT | Mesoscale Discussion | SPC | 4 hr |
| Mar 11, 4:48 AM CDT | Wind Chill Advisory | FGF | 31 hr |
| Mar 18, 4:08 PM CDT | River Flood Warning | FGF | 9 days |
| Mar 18, 4:08 PM CDT | River Flood Warning | FGF | 43 hr |
| Mar 19, 11:50 AM CDT | River Flood Watch | FGF | 6 days |
| Mar 19, 12:09 PM CDT | River Flood Watch | FGF | 6 days |
| Mar 20, 11:16 AM CDT | River Flood Warning | FGF | 46 days |
| Mar 20, 11:58 AM CDT | River Flood Warning | FGF | 26 days |
| Mar 20, 10:14 PM CDT | River Flood Warning | FGF | 45 days |
| Mar 21, 2:49 PM CDT | Areal Flood Warning | FGF | 4 days |
| Mar 22, 4:26 AM CDT | Wind Advisory | FGF | 18 hr |
| Mar 24, 3:51 PM CDT | Winter Storm Warning | FGF | 21 hr |
| Mar 24, 3:51 PM CDT | Winter Weather Advisory | FGF | 21 hr |
| Mar 24, 8:36 PM CDT | Mesoscale Discussion | SPC | 4 hr |
| Mar 25, 3:09 PM CDT | Areal Flood Warning | FGF | 6 days |
| Mar 28, 5:04 PM CDT | River Flood Warning | FGF | 51 min |
| Mar 29, 3:27 PM CDT | Winter Storm Warning | FGF | 61 hr |
| Mar 29, 3:27 PM CDT | Winter Weather Advisory | FGF | 61 hr |
| Mar 31, 2:34 PM CDT | Areal Flood Warning | FGF | 6 days |
| Apr 6, 2:04 PM CDT | Areal Flood Warning | FGF | 4 days |
| Apr 7, 12:56 PM CDT | River Flood Warning | FGF | 5 days |
| Apr 10, 11:08 AM CDT | Areal Flood Warning | FGF | 5 days |
| Apr 15, 1:54 PM CDT | Areal Flood Warning | FGF | 9 days |
| Apr 22, 5:19 PM CDT | Areal Flood Warning | FGF | 46 hr |
| Apr 23, 4:51 PM CDT | Wind Advisory | FGF | 11 hr |
| May 12, 8:42 PM CDT | Mesoscale Discussion | SPC | 93 min |
| May 13, 5:01 AM CDT | Wind Advisory | FGF | 16 hr |
| May 15, 2:50 PM CDT | Frost Advisory | FGF | 18 hr |
| May 29, 2:07 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 2, 10:31 AM CDT | Frost Advisory | FGF | 21 hr |
| Jun 19, 5:28 PM CDT | Severe Thunderstorm Warning | FGF | 62 min |
| Jun 23, 10:35 AM CDT | Mesoscale Discussion | SPC | 115 min |
| Jun 23, 11:01 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 26, 6:43 PM CDT | Tornado Watch | SPC | 4 hr |
| Jun 26, 9:06 PM CDT | Tornado Warning | FGF | 54 min |
| Jun 26, 9:19 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jun 26, 10:01 PM CDT | Special Weather Statement | FGF | 59 min |
| Jun 26, 10:11 PM CDT | Flash Flood Warning | FGF | 11 hr |
| Jun 27, 8:53 AM CDT | Areal Flood Warning | FGF | 3 days |
| Jun 27, 1:39 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 27, 3:16 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 27, 5:02 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 27, 7:16 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jul 9, 3:07 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 20, 6:09 AM CDT | Severe Thunderstorm Warning | FGF | 47 min |
| Jul 20, 1:07 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 23, 4:51 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jul 23, 9:29 PM CDT | Mesoscale Discussion | SPC | 61 min |
| Aug 2, 2:35 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Aug 7, 11:37 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Aug 14, 3:42 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Aug 14, 5:40 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 14, 8:37 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Aug 27, 5:10 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Sep 13, 3:34 AM CDT | Dense Fog Advisory | FGF | 6 hr |
| Sep 28, 4:02 AM CDT | Frost Advisory | FGF | 29 hr |
| Sep 30, 11:30 AM CDT | Wind Advisory | FGF | 8 hr |
| Oct 7, 4:58 PM CDT | Freeze Watch | FGF | 11 hr |
| Oct 8, 4:21 AM CDT | Freeze Warning | FGF | 30 hr |
| Oct 14, 4:11 AM CDT | Winter Weather Advisory | FGF | 27 hr |
| Nov 23, 7:30 AM CST | Freezing Rain Advisory | FGF | 3 hr |
| Dec 8, 2:20 PM CST | Wind Chill Advisory | FGF | 22 hr |
| Dec 9, 12:08 PM CST | Wind Chill Advisory | FGF | 22 hr |
| Dec 10, 3:28 PM CST | Wind Chill Advisory | FGF | 19 hr |
| Dec 12, 3:12 PM CST | Wind Chill Advisory | FGF | 20 hr |
| Dec 13, 11:14 AM CST | Wind Chill Advisory | FGF | 24 hr |
| Dec 14, 2:53 PM CST | Wind Chill Advisory | FGF | 21 hr |
| Dec 16, 10:29 PM CST | Freezing Rain Advisory | FGF | 5 hr |
| Dec 22, 3:57 AM CST | Winter Storm Watch | FGF | 24 hr |
| Dec 23, 4:10 AM CST | Winter Storm Warning | FGF | 3 days |
| Dec 24, 10:51 AM CST | Blizzard Warning | FGF | 46 hr |
| Dec 26, 9:01 AM CST | Winter Weather Advisory | FGF | 9 hr |
| Dec 27, 6:41 AM CST | Freezing Rain Advisory | FGF | 3 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 archive20082010
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.