Alert archive / Iowa / Shelby County
Weather alerts in Shelby County, Iowa, 2016
134 weather alerts in 2016, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Shelby County and its neighbors
Each county as a circle sized by its count in 2016. Tap one for its archive.
- Alerts
- 134
- Warnings
- 20
- Watches
- 18
- Advisories
- 29
- Busiest month
- July26 alerts
- Busiest day
- July 7, 20169 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Shelby County, 2016
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 11 | 6 | 45% | 5 | 100% | 6 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2016
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Omaha, NE: tornado warnings | 24 | 7 | 71% | 13 | 62% | 10 min |
| NWS Omaha, NE: severe thunderstorm warnings | 264 | 105 | 60% | 229 | 72% | 16 min |
| NWS Omaha, NE: flash flood warnings | 49 | 16 | 67% | 34 | 79% | 70 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 7, 5:20 AM CST | Dense Fog Advisory | OAX | 4 hr |
| Jan 7, 9:00 AM CST | Dense Fog Advisory | OAX | 2 hr |
| Jan 9, 3:50 AM CST | Wind Chill Advisory | OAX | 30 hr |
| Jan 16, 4:35 AM CST | Wind Chill Advisory | OAX | 31 hr |
| Jan 17, 3:42 PM CST | Wind Chill Advisory | OAX | 12 hr |
| Jan 18, 3:47 PM CST | Winter Weather Advisory | OAX | 25 hr |
| Jan 24, 3:10 PM CST | Winter Weather Advisory | OAX | 27 hr |
| Jan 30, 3:20 PM CST | Winter Storm Watch | OAX | 12 hr |
| Jan 31, 3:38 AM CST | Blizzard Watch | OAX | 36 hr |
| Feb 1, 4:37 AM CST | Winter Storm Warning | OAX | 47 hr |
| Feb 2, 3:39 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 2, 7:50 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Feb 3, 3:35 AM CST | Winter Weather Advisory | OAX | 8 hr |
| Feb 7, 3:09 PM CST | Wind Advisory | OAX | 27 hr |
| Feb 7, 10:54 PM CST | Winter Weather Advisory | OAX | 19 hr |
| Feb 18, 2:59 PM CST | Wind Advisory | OAX | 21 hr |
| Feb 28, 3:47 AM CST | Wind Advisory | OAX | 12 hr |
| Mar 14, 7:13 AM CDT | Dense Fog Advisory | OAX | 3 hr |
| Apr 3, 3:53 AM CDT | Red Flag Warning | OAX | 15 hr |
| Apr 5, 5:17 PM CDT | Wind Advisory | OAX | 22 hr |
| Apr 6, 3:33 PM CDT | Wind Advisory | OAX | 26 hr |
| Apr 7, 3:40 PM CDT | Freeze Watch | OAX | 12 hr |
| Apr 8, 3:17 AM CDT | Freeze Warning | OAX | 30 hr |
| Apr 11, 9:57 AM CDT | Freeze Warning | OAX | 23 hr |
| Apr 24, 1:31 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Apr 24, 2:28 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Apr 24, 6:10 PM CDT | Mesoscale Discussion | SPC | 65 min |
| Apr 24, 8:16 PM CDT | Special Weather Statement | OAX | 44 min |
| Apr 24, 8:45 PM CDT | Mesoscale Discussion | SPC | 60 min |
| May 9, 4:52 PM CDT | Mesoscale Discussion | SPC | 53 min |
| May 9, 5:13 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 9, 7:33 PM CDT | Mesoscale Discussion | SPC | 57 min |
| May 9, 9:40 PM CDT | Special Weather Statement | OAX | 35 min |
| May 9, 10:06 PM CDT | Mesoscale Discussion | SPC | 54 min |
| May 13, 10:30 AM CDT | Special Weather Statement | OAX | 45 min |
| May 13, 10:35 AM CDT | Special Weather Statement | OAX | 40 min |
| May 23, 1:58 PM CDT | Mesoscale Discussion | SPC | 92 min |
| May 25, 2:32 AM CDT | Special Weather Statement | OAX | 43 min |
| May 25, 11:34 PM CDT | Mesoscale Discussion | SPC | 86 min |
| May 26, 1:53 PM CDT | Tornado Watch | SPC | 8 hr |
| May 30, 5:14 PM CDT | Mesoscale Discussion | SPC | 91 min |
| May 30, 11:19 PM CDT | Severe Thunderstorm Warning | OAX | 26 min |
| May 30, 11:43 PM CDT | Special Weather Statement | OAX | 32 min |
| Jun 3, 3:06 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 14, 11:45 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 14, 12:43 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 14, 2:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 20, 12:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 20, 3:00 PM CDT | Special Weather Statement | OAX | 30 min |
| Jun 20, 4:10 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 20, 6:42 PM CDT | Mesoscale Discussion | SPC | 63 min |
| Jun 20, 9:04 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jun 25, 1:52 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 25, 9:57 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 29, 4:25 PM CDT | Special Weather Statement | OAX | 35 min |
| Jun 29, 4:55 PM CDT | Severe Thunderstorm Warning | OAX | 35 min |
| Jun 29, 5:28 PM CDT | Severe Thunderstorm Warning | OAX | 32 min |
| Jun 29, 5:36 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 29, 8:46 PM CDT | Special Weather Statement | OAX | 44 min |
| Jun 30, 1:29 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 5, 8:10 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 5, 10:15 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Jul 5, 10:46 PM CDT | Severe Thunderstorm Warning | OAX | 44 min |
| Jul 5, 11:42 PM CDT | Special Weather Statement | OAX | 33 min |
| Jul 7, 12:30 AM CDT | Mesoscale Discussion | SPC | 90 min |
| Jul 7, 1:12 AM CDT | Special Weather Statement | OAX | 48 min |
| Jul 7, 1:53 AM CDT | Special Weather Statement | OAX | 37 min |
| Jul 7, 1:50 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jul 7, 3:54 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 7, 5:57 PM CDT | Special Weather Statement | OAX | 33 min |
| Jul 7, 6:00 PM CDT | Severe Thunderstorm Warning | OAX | 29 min |
| Jul 7, 6:27 PM CDT | Special Weather Statement | OAX | 33 min |
| Jul 7, 6:30 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 11, 3:16 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Jul 11, 4:03 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 11, 8:43 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jul 17, 2:06 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 17, 3:27 AM CDT | Special Weather Statement | OAX | 48 min |
| Jul 17, 11:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 18, 2:23 AM CDT | Flash Flood Watch | OAX | 7 hr |
| Jul 18, 2:56 AM CDT | Areal Flood Advisory | OAX | 3 hr |
| Jul 18, 3:32 PM CDT | Excessive Heat Watch | OAX | 24 hr |
| Jul 19, 11:05 AM CDT | Special Weather Statement | OAX | 25 min |
| Jul 19, 11:26 AM CDT | Severe Thunderstorm Warning | OAX | 34 min |
| Jul 19, 12:28 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 19, 3:53 PM CDT | Excessive Heat Warning | OAX | 4 days |
| Aug 1, 10:24 AM CDT | Special Weather Statement | OAX | 36 min |
| Aug 3, 6:28 AM CDT | Dense Fog Advisory | OAX | 3 hr |
| Aug 4, 5:00 PM CDT | Special Weather Statement | OAX | 45 min |
| Aug 11, 3:49 AM CDT | Heat Advisory | OAX | 16 hr |
| Aug 11, 12:37 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 11, 3:26 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 11, 3:55 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 11, 6:17 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Aug 11, 6:35 PM CDT | Severe Thunderstorm Warning | OAX | 55 min |
| Aug 11, 7:13 PM CDT | Severe Thunderstorm Warning | OAX | 62 min |
| Aug 11, 9:07 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Aug 23, 2:05 PM CDT | Mesoscale Discussion | SPC | 55 min |
| Aug 23, 5:00 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Aug 23, 6:48 PM CDT | Special Weather Statement | OAX | 27 min |
| Aug 23, 8:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Aug 23, 10:01 PM CDT | Severe Thunderstorm Warning | OAX | 29 min |
| Aug 23, 10:27 PM CDT | Severe Thunderstorm Warning | OAX | 48 min |
| Aug 28, 5:27 PM CDT | Special Weather Statement | OAX | 33 min |
| Aug 28, 6:24 PM CDT | Areal Flood Advisory | OAX | 2 hr |
| Sep 6, 3:47 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 6, 7:00 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Sep 9, 10:42 AM CDT | Mesoscale Discussion | SPC | 93 min |
| Sep 12, 5:31 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Sep 12, 8:47 PM CDT | Special Weather Statement | OAX | 28 min |
| Sep 15, 3:45 PM CDT | Flash Flood Watch | OAX | 12 hr |
| Sep 15, 3:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Sep 15, 4:38 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Sep 15, 7:16 PM CDT | Severe Thunderstorm Warning | OAX | 44 min |
| Sep 15, 8:44 PM CDT | Flash Flood Warning | OAX | 5 hr |
| Sep 15, 8:49 PM CDT | Special Weather Statement | OAX | 41 min |
| Sep 16, 1:40 AM CDT | Flash Flood Warning | OAX | 3 hr |
| Sep 24, 1:16 PM CDT | Special Weather Statement | OAX | 29 min |
| Oct 11, 3:29 AM CDT | Freeze Watch | OAX | 24 hr |
| Oct 12, 3:25 AM CDT | Freeze Warning | OAX | 31 hr |
| Oct 15, 3:11 PM CDT | Dense Fog Advisory | OAX | 20 hr |
| Oct 16, 3:22 PM CDT | Dense Fog Advisory | OAX | 21 hr |
| Oct 27, 7:13 AM CDT | Dense Fog Advisory | OAX | 3 hr |
| Nov 17, 3:47 PM CST | Wind Advisory | OAX | 26 hr |
| Dec 15, 3:46 PM CST | Winter Weather Advisory | OAX | 50 hr |
| Dec 16, 3:35 AM CST | Wind Chill Warning | OAX | 55 hr |
| Dec 16, 3:35 AM CST | Wind Chill Advisory | OAX | 55 hr |
| Dec 23, 3:32 AM CST | Winter Weather Advisory | OAX | 9 hr |
| Dec 23, 3:48 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Dec 24, 1:54 AM CST | Dense Fog Advisory | OAX | 11 hr |
| Dec 24, 3:41 PM CST | Dense Fog Advisory | OAX | 17 hr |
| Dec 25, 4:20 PM CST | Special Weather Statement | OAX | 40 min |
| Dec 25, 4:57 PM CST | Special Weather Statement | OAX | 33 min |
| Dec 29, 9:09 AM CST | Wind Advisory | OAX | 7 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 | 11 |
| Severe Thunderstorm Watch | 10 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 42 |
| Special Weather Statement | 25 |
| Flooding | |
| Flash Flood Warning | 2 |
| Flash Flood Watch | 2 |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 1 |
| Blizzard Watch | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 6 |
| Heat | |
| Excessive Heat Warning | 1 |
| Excessive Heat Watch | 1 |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 3 |
| Wind Chill Warning | 1 |
| Freeze Watch | 2 |
| Wind Chill Advisory | 4 |
| Wind and dust | |
| Wind Advisory | 7 |
| Fire | |
| Red Flag Warning | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 9 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20152017
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.