Alert archive / Michigan / Gratiot County
Weather alerts in Gratiot County, Michigan, 2009
99 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Gratiot County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 99
- Warnings
- 18
- Watches
- 16
- Advisories
- 28
- Busiest month
- April20 alerts
- Busiest day
- April 25, 200910 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 1 tornado warnings covering Gratiot County in 2009 had a tornado report inside them.
Gratiot County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 6 | 2 | 67% | 1 | 100% | 36 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Rapids, MI: tornado warnings | 2 | 0 | 100% | 3 | 0% | |
| NWS Grand Rapids, MI: severe thunderstorm warnings | 40 | 22 | 45% | 85 | 62% | 24 min |
| NWS Grand Rapids, MI: flash flood warnings | 3 | 3 | 0% | 25 | 88% | 109 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, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 3, 3:24 PM EST | Freezing Rain Advisory | GRR | 22 hr |
| Jan 4, 6:56 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Jan 11, 3:38 PM EST | Winter Storm Watch | GRR | 23 hr |
| Jan 12, 2:32 PM EST | Winter Weather Advisory | GRR | 20 hr |
| Jan 14, 4:23 AM EST | Wind Chill Advisory | GRR | 3 days |
| Jan 16, 2:56 PM EST | Winter Storm Watch | GRR | 13 hr |
| Jan 17, 3:37 AM EST | Winter Storm Warning | GRR | 43 hr |
| Feb 3, 3:59 PM EST | Wind Chill Advisory | GRR | 20 hr |
| Feb 10, 12:04 PM EST | Flood Watch | GRR | 24 hr |
| Feb 10, 3:38 PM EST | Wind Advisory | GRR | 37 hr |
| Feb 11, 6:39 AM EST | Dense Fog Advisory | GRR | 5 hr |
| Feb 11, 11:56 AM EST | Areal Flood Warning | GRR | 23 hr |
| Feb 19, 3:53 PM EST | Winter Storm Watch | GRR | 24 hr |
| Feb 20, 3:43 PM EST | Winter Storm Warning | GRR | 27 hr |
| Feb 21, 6:35 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Feb 26, 8:38 PM EST | Areal Flood Advisory | GRR | 102 days |
| Mar 6, 3:12 PM EST | Flood Watch | GRR | 51 hr |
| Mar 10, 4:09 AM EDT | Wind Advisory | GRR | 36 hr |
| Apr 6, 2:04 AM EDT | Mesoscale Discussion | SPC | 4 hr |
| Apr 25, 10:23 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 25, 10:44 AM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Apr 25, 11:42 AM EDT | Special Weather Statement | GRR | 48 min |
| Apr 25, 11:55 AM EDT | Mesoscale Discussion | SPC | 95 min |
| Apr 25, 1:06 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Apr 25, 2:24 PM EDT | Severe Thunderstorm Warning | GRR | 50 min |
| Apr 25, 2:55 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Apr 25, 3:36 PM EDT | Special Weather Statement | GRR | 54 min |
| Apr 25, 5:43 PM EDT | Special Weather Statement | GRR | 62 min |
| Apr 25, 6:12 PM EDT | Severe Thunderstorm Warning | GRR | 21 min |
| Apr 26, 2:02 AM EDT | Areal Flood Advisory | GRR | 88 days |
| Apr 26, 2:09 PM EDT | Areal Flood Advisory | GRR | 87 days |
| Apr 26, 2:48 PM EDT | Areal Flood Warning | GRR | 5 hr |
| Apr 26, 2:51 PM EDT | River Flood Warning | GRR | 16 hr |
| Apr 26, 8:07 PM EDT | Areal Flood Advisory | GRR | 87 days |
| Apr 27, 3:18 AM EDT | Wind Advisory | GRR | 14 hr |
| Apr 27, 4:04 PM EDT | Flood Watch | GRR | 19 hr |
| Apr 28, 12:41 AM EDT | River Flood Advisory | GRR | 34 hr |
| Apr 28, 8:59 AM EDT | Areal Flood Advisory | GRR | 103 days |
| Apr 30, 10:43 PM EDT | River Flood Advisory | GRR | 13 hr |
| May 10, 3:47 AM EDT | Freeze Warning | GRR | 28 hr |
| May 11, 12:44 PM EDT | Freeze Warning | GRR | 19 hr |
| May 13, 11:18 PM EDT | Areal Flood Advisory | GRR | 87 days |
| May 13, 11:54 PM EDT | Special Weather Statement | GRR | 66 min |
| May 15, 3:40 PM EDT | Flood Watch | GRR | 12 hr |
| May 17, 2:58 PM EDT | Freeze Warning | GRR | 17 hr |
| May 30, 12:28 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 3, 3:47 PM EDT | Frost Advisory | GRR | 15 hr |
| Jun 8, 4:02 PM EDT | Tornado Watch | SPC | 6 hr |
| Jun 8, 5:46 PM EDT | Special Weather Statement | GRR | 59 min |
| Jun 8, 5:59 PM EDT | Severe Thunderstorm Warning | GRR | 61 min |
| Jun 8, 6:10 PM EDT | Tornado Warning | GRR | 35 min |
| Jun 8, 6:46 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jun 19, 4:29 AM EDT | Flash Flood Watch | GRR | 20 hr |
| Jun 19, 5:44 AM EDT | Special Weather Statement | GRR | 46 min |
| Jun 19, 7:04 PM EDT | Mesoscale Discussion | SPC | 86 min |
| Jun 25, 2:08 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 25, 4:12 PM EDT | Mesoscale Discussion | SPC | 63 min |
| Jul 5, 2:33 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 11, 3:31 AM EDT | Mesoscale Discussion | SPC | 29 min |
| Jul 22, 1:57 PM EDT | Special Weather Statement | GRR | 48 min |
| Jul 22, 2:53 PM EDT | Special Weather Statement | GRR | 112 min |
| Jul 25, 11:01 AM EDT | Special Weather Statement | GRR | 89 min |
| Aug 9, 1:10 AM EDT | Special Weather Statement | GRR | 65 min |
| Aug 9, 1:33 AM EDT | Severe Thunderstorm Warning | GRR | 27 min |
| Aug 9, 5:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Aug 9, 5:48 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 9, 7:40 PM EDT | Severe Thunderstorm Warning | GRR | 65 min |
| Aug 10, 1:58 AM EDT | Special Weather Statement | GRR | 92 min |
| Aug 10, 3:51 AM EDT | Special Weather Statement | GRR | 84 min |
| Aug 16, 4:41 PM EDT | Severe Thunderstorm Warning | GRR | 37 min |
| Aug 16, 7:35 PM EDT | Special Weather Statement | GRR | 55 min |
| Aug 19, 9:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Aug 27, 3:54 PM EDT | Flood Watch | GRR | 18 hr |
| Sep 22, 2:54 AM EDT | Dense Fog Advisory | GRR | 7 hr |
| Sep 27, 3:00 PM EDT | Wind Advisory | GRR | 31 hr |
| Sep 27, 10:14 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 27, 10:46 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Sep 27, 11:44 PM EDT | Special Weather Statement | GRR | 61 min |
| Sep 28, 12:29 AM EDT | Special Weather Statement | GRR | 61 min |
| Sep 30, 3:56 AM EDT | Freeze Warning | GRR | 29 hr |
| Oct 6, 4:23 PM EDT | Special Weather Statement | GRR | 67 min |
| Oct 6, 9:12 PM EDT | Special Weather Statement | GRR | 93 min |
| Oct 10, 2:41 AM EDT | Dense Fog Advisory | GRR | 6 hr |
| Oct 10, 2:41 AM EDT | Freeze Warning | GRR | 29 hr |
| Oct 30, 3:46 PM EDT | Wind Advisory | GRR | 12 hr |
| Oct 30, 7:19 PM EDT | Special Weather Statement | GRR | 116 min |
| Oct 30, 9:17 PM EDT | Special Weather Statement | GRR | 73 min |
| Nov 8, 12:25 AM EST | Dense Fog Advisory | GRR | 9 hr |
| Nov 21, 9:34 PM EST | Dense Fog Advisory | GRR | 12 hr |
| Dec 3, 2:40 PM EST | Winter Weather Advisory | GRR | 25 hr |
| Dec 7, 4:00 AM EST | Winter Storm Watch | GRR | 49 hr |
| Dec 7, 3:47 PM EST | Winter Storm Warning | GRR | 37 hr |
| Dec 9, 12:09 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Dec 9, 4:30 AM EST | Winter Weather Advisory | GRR | 48 hr |
| Dec 12, 8:04 PM EST | Winter Weather Advisory | GRR | 15 hr |
| Dec 22, 4:14 PM EST | Winter Storm Watch | GRR | 36 hr |
| Dec 24, 3:45 AM EST | Winter Weather Advisory | GRR | 33 hr |
| Dec 24, 7:28 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Dec 26, 12:54 AM EST | Winter Weather Advisory | GRR | 10 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.