Alert archive / Iowa / Polk County
Weather alerts in Polk County, Iowa, 2015
151 weather alerts in 2015, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Polk County and its neighbors
Each county as a circle sized by its count in 2015. Tap one for its archive.
- Alerts
- 151
- Warnings
- 48
- Watches
- 25
- Advisories
- 30
- Busiest month
- June33 alerts
- Busiest day
- June 25, 20159 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 3 tornado reports fell inside a warning.
Polk County, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 3 | 0% | |||
| Severe thunderstorm warnings | 9 | 5 | 44% | 12 | 83% | 16 min |
| Flash flood warnings | 2 | 2 | 0% | 7 | 43% | 125 min |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Des Moines, IA: tornado warnings | 38 | 14 | 63% | 37 | 62% | 13 min |
| NWS Des Moines, IA: severe thunderstorm warnings | 201 | 101 | 50% | 301 | 78% | 19 min |
| NWS Des Moines, IA: flash flood warnings | 39 | 22 | 44% | 86 | 86% | 121 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 3, 3:51 AM CST | Winter Weather Advisory | DMX | 26 hr |
| Jan 4, 4:00 AM CST | Winter Storm Watch | DMX | 24 hr |
| Jan 4, 6:07 AM CST | Wind Chill Advisory | DMX | 27 hr |
| Jan 4, 3:42 PM CST | Winter Storm Warning | DMX | 31 hr |
| Jan 5, 12:25 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 6, 4:15 AM CST | Wind Chill Warning | DMX | 32 hr |
| Jan 6, 4:15 AM CST | Wind Chill Advisory | DMX | 53 hr |
| Jan 7, 3:44 PM CST | Winter Weather Advisory | DMX | 38 hr |
| Jan 8, 4:57 PM CST | Special Weather Statement | DMX | 48 min |
| Jan 9, 5:38 AM CST | Wind Chill Advisory | DMX | 6 hr |
| Jan 28, 3:36 PM CST | Wind Advisory | DMX | 17 hr |
| Jan 30, 10:48 AM CST | Winter Storm Watch | DMX | 17 hr |
| Jan 31, 3:31 AM CST | Winter Storm Warning | DMX | 41 hr |
| Jan 31, 10:13 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 17, 3:51 AM CST | Wind Chill Advisory | DMX | 32 hr |
| Feb 20, 3:08 PM CST | Wind Chill Advisory | DMX | 67 hr |
| Feb 24, 11:34 AM CST | Winter Storm Watch | DMX | 4 hr |
| Feb 24, 3:19 PM CST | Winter Storm Warning | DMX | 30 hr |
| Feb 24, 3:19 PM CST | Winter Weather Advisory | DMX | 30 hr |
| Feb 26, 9:48 PM CST | Wind Chill Advisory | DMX | 11 hr |
| Mar 2, 4:11 PM CST | Winter Weather Advisory | DMX | 19 hr |
| Mar 14, 11:06 AM CDT | Fire Weather Watch | DMX | 17 hr |
| Mar 15, 3:41 AM CDT | Red Flag Warning | DMX | 15 hr |
| Mar 16, 3:43 AM CDT | Red Flag Warning | DMX | 15 hr |
| Mar 28, 3:44 PM CDT | Wind Advisory | DMX | 26 hr |
| Mar 30, 4:14 AM CDT | Red Flag Warning | DMX | 15 hr |
| Mar 31, 3:38 PM CDT | Fire Weather Watch | DMX | 12 hr |
| Apr 1, 3:46 AM CDT | Red Flag Warning | DMX | 15 hr |
| Apr 8, 12:09 PM CDT | Special Weather Statement | DMX | 36 min |
| Apr 8, 12:23 PM CDT | Severe Thunderstorm Warning | DMX | 37 min |
| Apr 12, 10:48 PM CDT | Special Weather Statement | DMX | 42 min |
| Apr 18, 6:49 PM CDT | Special Weather Statement | DMX | 41 min |
| Apr 20, 3:45 AM CDT | Wind Advisory | DMX | 15 hr |
| Apr 22, 3:23 PM CDT | Freeze Warning | DMX | 17 hr |
| May 10, 9:19 PM CDT | Mesoscale Discussion | SPC | 56 min |
| May 15, 12:05 AM CDT | Dense Fog Advisory | DMX | 9 hr |
| May 25, 5:33 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 25, 8:18 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jun 6, 3:37 PM CDT | Flash Flood Watch | DMX | 12 hr |
| Jun 6, 11:23 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 7, 1:43 AM CDT | Special Weather Statement | DMX | 47 min |
| Jun 7, 1:56 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 7, 2:32 AM CDT | Special Weather Statement | DMX | 43 min |
| Jun 10, 2:12 PM CDT | Flash Flood Watch | DMX | 38 hr |
| Jun 10, 8:38 PM CDT | Special Weather Statement | DMX | 52 min |
| Jun 11, 12:52 PM CDT | River Flood Warning | DMX | 8 days |
| Jun 11, 12:53 PM CDT | River Flood Warning | DMX | 7 days |
| Jun 11, 1:27 PM CDT | River Flood Warning | DMX | 42 hr |
| Jun 15, 3:18 AM CDT | Flash Flood Warning | DMX | 6 hr |
| Jun 15, 4:17 AM CDT | River Flood Warning | DMX | 55 hr |
| Jun 15, 5:25 PM CDT | River Flood Warning | DMX | 40 hr |
| Jun 20, 12:48 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jun 20, 3:10 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 20, 3:49 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 20, 6:33 PM CDT | Mesoscale Discussion | SPC | 57 min |
| Jun 20, 10:12 PM CDT | Mesoscale Discussion | SPC | 63 min |
| Jun 22, 1:22 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Jun 23, 3:59 PM CDT | Flash Flood Watch | DMX | 38 hr |
| Jun 24, 12:39 AM CDT | Mesoscale Discussion | SPC | 66 min |
| Jun 24, 5:58 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 24, 6:21 PM CDT | Tornado Watch | SPC | 5 hr |
| Jun 24, 11:26 PM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Jun 25, 12:59 AM CDT | Flash Flood Warning | DMX | 6 hr |
| Jun 25, 1:25 AM CDT | Severe Thunderstorm Warning | DMX | 35 min |
| Jun 25, 1:54 AM CDT | River Flood Warning | DMX | 6 days |
| Jun 25, 1:54 AM CDT | River Flood Warning | DMX | 5 days |
| Jun 25, 1:54 AM CDT | River Flood Warning | DMX | 5 days |
| Jun 25, 2:27 AM CDT | River Flood Warning | DMX | 6 days |
| Jun 25, 5:07 AM CDT | River Flood Warning | DMX | 4 days |
| Jun 25, 6:57 AM CDT | Areal Flood Warning | DMX | 9 hr |
| Jun 28, 4:38 AM CDT | Special Weather Statement | DMX | 52 min |
| Jul 11, 3:19 PM CDT | Heat Advisory | DMX | 28 hr |
| Jul 11, 3:19 PM CDT | Heat Advisory | DMX | 52 hr |
| Jul 15, 11:52 PM CDT | Flash Flood Watch | DMX | 10 hr |
| Jul 18, 4:12 AM CDT | Heat Advisory | DMX | 12 hr |
| Jul 24, 11:16 AM CDT | Special Weather Statement | DMX | 59 min |
| Jul 26, 1:13 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 26, 4:49 AM CDT | Severe Thunderstorm Warning | DMX | 26 min |
| Jul 27, 11:41 AM CDT | Special Weather Statement | DMX | 64 min |
| Jul 27, 12:13 PM CDT | Severe Thunderstorm Warning | DMX | 32 min |
| Jul 27, 12:40 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 27, 12:45 PM CDT | Special Weather Statement | DMX | 45 min |
| Jul 28, 3:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 28, 3:59 PM CDT | Flash Flood Watch | DMX | 11 hr |
| Jul 28, 7:56 PM CDT | Special Weather Statement | DMX | 34 min |
| Jul 28, 8:04 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 28, 9:39 PM CDT | River Flood Warning | DMX | 34 hr |
| Jul 28, 11:58 PM CDT | River Flood Warning | DMX | 57 hr |
| Aug 2, 4:48 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 2, 5:22 PM CDT | Severe Thunderstorm Warning | DMX | 38 min |
| Aug 2, 6:22 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Aug 8, 3:42 PM CDT | Flash Flood Watch | DMX | 15 hr |
| Aug 8, 11:33 PM CDT | Severe Thunderstorm Warning | DMX | 42 min |
| Aug 9, 12:18 AM CDT | Special Weather Statement | DMX | 57 min |
| Aug 22, 2:13 PM CDT | Mesoscale Discussion | SPC | 62 min |
| Aug 22, 2:55 PM CDT | Mesoscale Discussion | SPC | 65 min |
| Aug 22, 3:48 PM CDT | Tornado Watch | SPC | 8 hr |
| Aug 22, 6:21 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Aug 22, 8:49 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Aug 28, 3:01 PM CDT | River Flood Warning | DMX | 64 hr |
| Aug 29, 7:36 AM CDT | River Flood Warning | DMX | 4 days |
| Aug 30, 6:08 AM CDT | Dense Fog Advisory | DMX | 4 hr |
| Sep 6, 4:06 AM CDT | Flash Flood Watch | DMX | 28 hr |
| Sep 6, 6:02 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Sep 6, 8:42 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Sep 6, 9:12 PM CDT | Severe Thunderstorm Warning | DMX | 28 min |
| Sep 6, 9:39 PM CDT | Special Weather Statement | DMX | 51 min |
| Sep 6, 11:41 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Sep 7, 4:21 AM CDT | Flash Flood Watch | DMX | 30 hr |
| Sep 7, 10:48 PM CDT | River Flood Warning | DMX | 4 days |
| Sep 8, 1:43 PM CDT | River Flood Warning | DMX | 41 hr |
| Sep 17, 5:47 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Oct 11, 3:59 PM CDT | Wind Advisory | DMX | 26 hr |
| Oct 16, 3:54 AM CDT | Frost Advisory | DMX | 29 hr |
| Oct 18, 2:56 PM CDT | Red Flag Warning | DMX | 28 hr |
| Oct 21, 9:07 AM CDT | Special Weather Statement | DMX | 53 min |
| Nov 3, 8:35 AM CST | Dense Fog Advisory | DMX | 2 hr |
| Nov 5, 3:17 PM CST | Mesoscale Discussion | SPC | 118 min |
| Nov 10, 3:20 AM CST | High Wind Watch | DMX | 24 hr |
| Nov 10, 3:39 PM CST | High Wind Warning | DMX | 38 hr |
| Nov 10, 3:39 PM CST | Wind Advisory | DMX | 50 hr |
| Nov 11, 10:17 AM CST | Mesoscale Discussion | SPC | 118 min |
| Nov 11, 11:25 AM CST | Tornado Watch | SPC | 6 hr |
| Nov 11, 1:42 PM CST | Mesoscale Discussion | SPC | 93 min |
| Nov 11, 2:13 PM CST | Special Weather Statement | DMX | 92 min |
| Nov 11, 3:07 PM CST | Severe Thunderstorm Warning | DMX | 53 min |
| Nov 11, 3:52 PM CST | Severe Thunderstorm Warning | DMX | 53 min |
| Nov 18, 3:12 PM CST | Wind Advisory | DMX | 27 hr |
| Nov 18, 4:05 PM CST | Winter Storm Watch | DMX | 36 hr |
| Nov 19, 3:41 PM CST | Winter Storm Warning | DMX | 38 hr |
| Nov 20, 1:51 PM CST | Mesoscale Discussion | SPC | 5 hr |
| Nov 20, 7:33 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Nov 25, 4:39 PM CST | Winter Weather Advisory | DMX | 34 hr |
| Nov 29, 3:46 PM CST | Winter Weather Advisory | DMX | 36 hr |
| Dec 6, 8:12 PM CST | Dense Fog Advisory | DMX | 15 hr |
| Dec 12, 4:10 PM CST | Dense Fog Advisory | DMX | 12 hr |
| Dec 13, 7:47 AM CST | Flood Watch | DMX | 25 hr |
| Dec 13, 1:03 PM CST | River Flood Warning | DMX | 12 days |
| Dec 13, 1:03 PM CST | River Flood Warning | DMX | 9 days |
| Dec 13, 9:27 PM CST | River Flood Warning | DMX | 6 days |
| Dec 13, 9:27 PM CST | River Flood Warning | DMX | 6 days |
| Dec 14, 8:45 AM CST | River Flood Warning | DMX | 56 hr |
| Dec 14, 9:59 AM CST | River Flood Warning | DMX | 31 hr |
| Dec 14, 11:32 AM CST | River Flood Warning | DMX | 4 days |
| Dec 24, 3:27 AM CST | Winter Weather Advisory | DMX | 15 hr |
| Dec 25, 4:38 AM CST | Dense Fog Advisory | DMX | 4 hr |
| Dec 25, 9:10 AM CST | Dense Fog Advisory | DMX | 6 hr |
| Dec 26, 3:46 PM CST | Winter Storm Watch | DMX | 23 hr |
| Dec 27, 4:46 AM CST | Winter Storm Warning | DMX | 49 hr |
| Dec 28, 3:35 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Dec 28, 3:42 PM CST | 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.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20142016
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.