Alert archive / Michigan / Mason County
Weather alerts in Mason County, Michigan, 2020
92 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Mason County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 92
- Warnings
- 14
- Watches
- 12
- Advisories
- 31
- Busiest month
- August13 alerts
- Busiest day
- June 3, 20203 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Mason County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 5 | 3 | 40% | 8 | 88% | 37 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Rapids, MI: severe thunderstorm warnings | 87 | 49 | 44% | 198 | 75% | 30 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, 2:58 PM EST | Lakeshore Flood Advisory | GRR | 70 hr |
| Jan 6, 3:34 PM EST | Lakeshore Flood Advisory | GRR | 43 hr |
| Jan 9, 10:15 AM EST | Winter Storm Watch | GRR | 18 hr |
| Jan 10, 3:47 AM EST | Winter Storm Warning | GRR | 47 hr |
| Jan 16, 3:46 PM EST | Winter Weather Advisory | GRR | 72 hr |
| Jan 16, 4:05 PM EST | Lakeshore Flood Watch | GRR | 5 hr |
| Jan 16, 9:15 PM EST | Lakeshore Flood Warning | GRR | 68 hr |
| Jan 21, 12:19 PM EST | Lakeshore Flood Advisory | GRR | 28 hr |
| Feb 8, 2:29 PM EST | Winter Weather Advisory | GRR | 33 hr |
| Feb 11, 3:47 PM EST | Winter Weather Advisory | GRR | 66 hr |
| Feb 14, 9:56 AM EST | Lakeshore Flood Warning | GRR | 31 hr |
| Feb 17, 3:35 AM EST | Winter Weather Advisory | GRR | 30 hr |
| Feb 21, 4:08 AM EST | Lakeshore Flood Advisory | GRR | 21 hr |
| Mar 12, 3:40 PM EDT | Lakeshore Flood Advisory | GRR | 28 hr |
| Mar 19, 3:48 AM EDT | Lakeshore Flood Advisory | GRR | 40 hr |
| Apr 7, 4:06 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Apr 7, 4:55 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Apr 8, 3:54 PM EDT | Lakeshore Flood Advisory | GRR | 40 hr |
| Apr 11, 3:29 PM EDT | High Wind Watch | GRR | 21 hr |
| Apr 11, 3:29 PM EDT | Lakeshore Flood Watch | GRR | 12 hr |
| Apr 12, 3:37 AM EDT | Lakeshore Flood Warning | GRR | 41 hr |
| Apr 12, 12:42 PM EDT | Wind Advisory | GRR | 31 hr |
| Apr 28, 3:33 AM EDT | Dense Fog Advisory | GRR | 6 hr |
| Apr 28, 3:31 PM EDT | Lakeshore Flood Advisory | GRR | 52 hr |
| May 16, 11:56 AM EDT | Flood Watch | GRR | 21 hr |
| May 16, 3:30 PM EDT | Lakeshore Flood Advisory | GRR | 57 hr |
| May 17, 8:26 AM EDT | Flood Watch | GRR | 18 hr |
| May 27, 3:10 PM EDT | Special Weather Statement | GRR | 4 hr |
| May 30, 3:32 PM EDT | Frost Advisory | GRR | 16 hr |
| Jun 1, 3:57 AM EDT | Beach Hazards Statement | GRR | 34 hr |
| Jun 2, 10:28 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 2, 10:50 PM EDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Jun 2, 11:07 PM EDT | Severe Thunderstorm Warning | GRR | 83 min |
| Jun 9, 3:42 AM EDT | Wind Advisory | GRR | 28 hr |
| Jun 9, 3:32 PM EDT | Beach Hazards Statement | GRR | 54 hr |
| Jun 11, 5:14 PM EDT | Special Weather Statement | GRR | 3 hr |
| Jun 22, 6:01 AM EDT | Beach Hazards Statement | GRR | 38 hr |
| Jun 26, 6:09 PM EDT | Special Weather Statement | GRR | 111 min |
| Jul 9, 1:16 PM EDT | Special Weather Statement | GRR | 4 hr |
| Jul 9, 10:03 PM EDT | Beach Hazards Statement | GRR | 25 hr |
| Jul 11, 3:51 PM EDT | Beach Hazards Statement | GRR | 30 hr |
| Jul 17, 3:43 PM EDT | Beach Hazards Statement | GRR | 56 hr |
| Jul 19, 7:07 AM EDT | Severe Thunderstorm Warning | GRR | 39 min |
| Jul 26, 10:45 AM EDT | Beach Hazards Statement | GRR | 11 hr |
| Jul 26, 6:33 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Aug 2, 10:10 AM EDT | Beach Hazards Statement | GRR | 59 hr |
| Aug 7, 3:40 PM EDT | Beach Hazards Statement | GRR | 35 hr |
| Aug 8, 1:04 PM EDT | Special Weather Statement | GRR | 56 min |
| Aug 10, 4:46 PM EDT | Mesoscale Discussion | SPC | 89 min |
| Aug 10, 8:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Aug 19, 7:37 PM EDT | Beach Hazards Statement | GRR | 26 hr |
| Aug 26, 3:20 AM EDT | Beach Hazards Statement | GRR | 34 hr |
| Aug 26, 4:09 AM EDT | Severe Thunderstorm Warning | GRR | 66 min |
| Aug 27, 10:41 AM EDT | Severe Thunderstorm Warning | GRR | 54 min |
| Aug 27, 11:02 AM EDT | Mesoscale Discussion | SPC | 118 min |
| Aug 28, 3:45 AM EDT | Beach Hazards Statement | GRR | 52 hr |
| Aug 28, 1:50 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Aug 31, 3:19 AM EDT | Beach Hazards Statement | GRR | 21 hr |
| Sep 2, 6:38 AM EDT | Beach Hazards Statement | GRR | 63 hr |
| Sep 5, 3:43 PM EDT | Beach Hazards Statement | GRR | 52 hr |
| Sep 6, 7:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Sep 6, 9:38 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Sep 7, 12:20 AM EDT | Mesoscale Discussion | SPC | 115 min |
| Sep 13, 4:00 AM EDT | Beach Hazards Statement | GRR | 12 hr |
| Sep 14, 3:14 PM EDT | Beach Hazards Statement | GRR | 50 hr |
| Sep 17, 3:38 AM EDT | Frost Advisory | GRR | 28 hr |
| Sep 18, 9:03 AM EDT | Freeze Warning | GRR | 24 hr |
| Sep 19, 11:38 AM EDT | Frost Advisory | GRR | 21 hr |
| Sep 20, 11:39 AM EDT | Beach Hazards Statement | GRR | 32 hr |
| Sep 25, 12:45 PM EDT | Beach Hazards Statement | GRR | 51 hr |
| Oct 2, 11:16 AM EDT | Frost Advisory | GRR | 21 hr |
| Oct 16, 3:54 PM EDT | Wind Advisory | GRR | 34 hr |
| Oct 17, 11:26 AM EDT | Lakeshore Flood Advisory | GRR | 17 hr |
| Oct 23, 9:09 AM EDT | Lakeshore Flood Advisory | GRR | 24 hr |
| Oct 30, 2:47 PM EDT | Lakeshore Flood Warning | GRR | 58 hr |
| Oct 31, 4:29 AM EDT | Wind Advisory | GRR | 40 hr |
| Nov 9, 11:44 AM EST | Lakeshore Flood Statement | GRR | 12 hr |
| Nov 10, 11:36 AM EST | Wind Advisory | GRR | 17 hr |
| Nov 10, 6:52 PM EST | Severe Thunderstorm Warning | GRR | 83 min |
| Nov 13, 5:20 PM EST | Lakeshore Flood Watch | GRR | 17 hr |
| Nov 13, 5:25 PM EST | High Wind Watch | GRR | 10 hr |
| Nov 14, 3:27 AM EST | High Wind Warning | GRR | 42 hr |
| Nov 14, 9:50 AM EST | Lakeshore Flood Warning | GRR | 39 hr |
| Nov 15, 9:53 PM EST | Wind Advisory | GRR | 6 hr |
| Nov 18, 3:45 AM EST | Lakeshore Flood Advisory | GRR | 36 hr |
| Nov 23, 3:28 PM EST | Winter Weather Advisory | GRR | 36 hr |
| Dec 10, 1:06 AM EST | Freezing Fog Advisory | GRR | 8 hr |
| Dec 10, 2:54 PM EST | Winter Storm Watch | GRR | 13 hr |
| Dec 11, 3:28 AM EST | Winter Storm Warning | GRR | 41 hr |
| Dec 23, 3:59 AM EST | Winter Weather Advisory | GRR | 59 hr |
| Dec 28, 3:28 PM EST | Winter Weather Advisory | GRR | 44 hr |
| Dec 29, 8:50 PM EST | Mesoscale Discussion | SPC | 4 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 5 |
| Severe Thunderstorm Watch | 3 |
| Mesoscale Discussion | 10 |
| Special Weather Statement | 5 |
| Flooding | |
| Flood Watch | 2 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 7 |
| Cold | |
| Freeze Warning | 1 |
| Frost Advisory | 4 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 2 |
| Wind Advisory | 6 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
| Freezing Fog Advisory | 1 |
| Coast and beach | |
| Lakeshore Flood Warning | 5 |
| Lakeshore Flood Watch | 3 |
| Lakeshore Flood Advisory | 12 |
| Beach Hazards Statement | 19 |
| Lakeshore Flood Statement | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.