Alert archive / Michigan / Ottawa County
Weather alerts in Ottawa County, Michigan, 2009
108 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Ottawa County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 108
- Warnings
- 25
- Watches
- 18
- Advisories
- 42
- Busiest month
- June14 alerts
- Busiest day
- June 19, 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.
Ottawa County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 6 | 5 | 17% | 9 | 78% | 25 min |
| Flash flood warnings | 2 | 2 | 0% | 9 | 78% | 125 min |
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 7, 3:16 PM EST | Lake Effect Snow Advisory | GRR | 25 hr |
| Jan 10, 4:16 AM EST | Winter Weather Advisory | GRR | 14 hr |
| Jan 11, 3:38 PM EST | Winter Storm Watch | GRR | 23 hr |
| Jan 12, 2:32 PM EST | Winter Storm Warning | GRR | 24 hr |
| Jan 13, 10:55 PM EST | Lake Effect Snow Watch | GRR | 17 hr |
| Jan 14, 4:23 AM EST | Wind Chill Advisory | GRR | 3 days |
| Jan 14, 3:39 PM EST | Lake Effect Snow Advisory | GRR | 36 hr |
| Jan 17, 3:37 AM EST | Winter Storm Warning | GRR | 43 hr |
| Jan 17, 3:37 AM EST | Winter Weather Advisory | GRR | 43 hr |
| Jan 29, 11:45 AM EST | Lake Effect Snow Advisory | GRR | 28 hr |
| Feb 10, 3:39 AM EST | High Wind Watch | GRR | 12 hr |
| Feb 10, 12:04 PM EST | Flood Watch | GRR | 24 hr |
| Feb 10, 3:38 PM EST | Wind Advisory | GRR | 37 hr |
| Feb 10, 9:30 PM EST | River Flood Warning | GRR | 7 days |
| 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 17, 3:44 PM EST | Winter Weather Advisory | GRR | 51 hr |
| Feb 18, 4:12 PM EST | Winter Storm Warning | GRR | 27 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 21, 4:17 PM EST | Lake Effect Snow Advisory | GRR | 35 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 9, 12:01 PM EDT | River Flood Advisory | GRR | 24 hr |
| Mar 10, 4:09 AM EDT | Wind Advisory | GRR | 36 hr |
| Mar 10, 11:37 AM EDT | River Flood Warning | GRR | 6 days |
| 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, 1:23 PM EDT | Special Weather Statement | GRR | 37 min |
| Apr 25, 2:34 PM EDT | Severe Thunderstorm Warning | GRR | 41 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, 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, 12:30 AM EDT | River Flood Warning | GRR | 8 days |
| Apr 28, 8:59 AM EDT | Areal Flood Advisory | GRR | 103 days |
| May 8, 4:21 PM EDT | Wind Advisory | GRR | 23 hr |
| May 10, 3:47 AM EDT | Frost Advisory | GRR | 28 hr |
| May 11, 12:44 PM EDT | Frost Advisory | GRR | 19 hr |
| May 13, 11:17 PM EDT | Mesoscale Discussion | SPC | 58 min |
| May 13, 11:51 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| 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 | Frost Advisory | GRR | 17 hr |
| Jun 8, 4:02 PM EDT | Tornado Watch | SPC | 6 hr |
| Jun 8, 6:42 PM EDT | Severe Thunderstorm Warning | GRR | 63 min |
| Jun 8, 6:46 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jun 19, 12:07 AM EDT | Mesoscale Discussion | SPC | 53 min |
| Jun 19, 12:30 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 19, 2:50 AM EDT | Flash Flood Warning | GRR | 6 hr |
| 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, 1:06 PM EDT | Special Weather Statement | GRR | 114 min |
| Jun 19, 7:04 PM EDT | Mesoscale Discussion | SPC | 86 min |
| Jun 19, 7:53 PM EDT | Special Weather Statement | GRR | 82 min |
| Jun 19, 8:35 PM EDT | Flash Flood Warning | GRR | 6 hr |
| Jun 19, 8:36 PM EDT | Severe Thunderstorm Warning | GRR | 39 min |
| Jun 20, 2:23 AM EDT | Areal Flood Warning | GRR | 57 hr |
| Jul 11, 3:31 AM EDT | Mesoscale Discussion | SPC | 29 min |
| Jul 19, 11:14 AM EDT | Special Weather Statement | GRR | 61 min |
| Jul 22, 1:57 PM EDT | Special Weather Statement | GRR | 48 min |
| Jul 24, 4:25 AM EDT | Dense Fog Advisory | GRR | 4 hr |
| Aug 8, 7:33 AM EDT | Special Weather Statement | GRR | 72 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, 6:01 PM EDT | Severe Thunderstorm Warning | GRR | 66 min |
| Aug 9, 6:45 PM EDT | Severe Thunderstorm Warning | GRR | 60 min |
| Aug 10, 12:42 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 10, 12:50 AM EDT | Special Weather Statement | GRR | 55 min |
| Aug 10, 1:37 AM EDT | Areal Flood Advisory | GRR | 7 hr |
| Aug 10, 1:58 AM EDT | Special Weather Statement | GRR | 92 min |
| Aug 25, 7:47 PM EDT | Special Weather Statement | GRR | 43 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 | High Wind Warning | GRR | 31 hr |
| Sep 27, 10:14 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 27, 10:41 PM EDT | Special Weather Statement | GRR | 94 min |
| Sep 27, 10:46 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Sep 27, 10:51 PM EDT | Severe Thunderstorm Warning | GRR | 39 min |
| Sep 28, 9:52 PM EDT | Wind Advisory | GRR | 11 hr |
| Sep 30, 3:56 AM EDT | Frost Advisory | GRR | 17 hr |
| Sep 30, 3:56 AM EDT | Freeze Warning | GRR | 29 hr |
| Oct 6, 12:04 PM EDT | Wind Advisory | GRR | 22 hr |
| Oct 6, 9:50 PM EDT | High Wind Warning | GRR | 6 hr |
| Oct 10, 2:41 AM EDT | Dense Fog Advisory | GRR | 6 hr |
| Oct 10, 2:41 AM EDT | Freeze Warning | GRR | 29 hr |
| Oct 23, 10:36 AM EDT | Areal Flood Advisory | GRR | 4 hr |
| Oct 30, 4:51 AM EDT | Areal Flood Advisory | GRR | 31 hr |
| Oct 30, 3:46 PM EDT | Wind Advisory | GRR | 12 hr |
| 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 3, 10:43 PM EST | Winter Storm Warning | GRR | 17 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 | Blizzard Warning | 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 23, 9:50 PM EST | Winter Weather Advisory | GRR | 10 hr |
| Dec 24, 3:45 AM EST | Winter Weather Advisory | GRR | 33 hr |
| Dec 26, 12:54 AM EST | Winter Weather Advisory | GRR | 10 hr |
| Dec 26, 3:48 PM EST | Winter Weather Advisory | GRR | 2 hr |
| Dec 26, 6:08 PM EST | Winter Storm Warning | GRR | 17 hr |
| Dec 27, 3:22 PM EST | Winter Weather Advisory | GRR | 6 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.