Alert archive / Iowa / Black Hawk County
Weather alerts in Black Hawk County, Iowa, 2009
134 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Black Hawk County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 134
- Warnings
- 35
- Watches
- 23
- Advisories
- 42
- Busiest month
- June25 alerts
- Busiest day
- August 9, 20099 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 4 tornado warnings covering Black Hawk County in 2009 had a tornado report inside them.
Black Hawk County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 10 | 6 | 40% | 17 | 100% | 31 min |
| Flash flood warnings | 1 | 1 | 0% | 3 | 67% | 245 min |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Des Moines, IA: tornado warnings | 17 | 7 | 59% | 24 | 83% | 16 min |
| NWS Des Moines, IA: severe thunderstorm warnings | 194 | 106 | 45% | 399 | 80% | 22 min |
| NWS Des Moines, IA: flash flood warnings | 12 | 5 | 58% | 27 | 85% | 110 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 | 20 hr |
| Jan 9, 9:32 PM CST | Winter Weather Advisory | DMX | 11 hr |
| Jan 11, 3:57 AM CST | Blizzard Watch | DMX | 24 hr |
| Jan 11, 4:24 PM CST | Winter Weather Advisory | DMX | 31 hr |
| Jan 12, 4:00 AM CST | Blizzard Warning | DMX | 17 hr |
| Jan 12, 4:00 AM CST | Wind Chill Advisory | DMX | 32 hr |
| Jan 12, 6:27 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 13, 3:55 AM CST | Winter Weather Advisory | DMX | 24 hr |
| Jan 13, 6:12 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 13, 11:38 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 14, 3:50 AM CST | Wind Chill Warning | DMX | 54 hr |
| Jan 14, 8:50 AM CST | Winter Weather Advisory | DMX | 6 hr |
| Jan 23, 3:38 AM CST | Wind Chill Advisory | DMX | 32 hr |
| Jan 23, 7:02 AM CST | Wind Advisory | DMX | 4 hr |
| Jan 23, 9:39 AM CST | Winter Weather Advisory | DMX | 4 hr |
| Jan 23, 2:15 PM CST | Winter Weather Advisory | DMX | 4 hr |
| Feb 2, 3:16 PM CST | Wind Chill Advisory | DMX | 19 hr |
| Feb 9, 12:00 PM CST | Wind Advisory | DMX | 16 hr |
| Feb 11, 9:30 PM CST | River Flood Warning | DMX | 31 hr |
| Feb 14, 2:23 PM CST | River Flood Warning | DMX | 29 hr |
| Feb 20, 3:53 AM CST | Winter Weather Advisory | DMX | 32 hr |
| Feb 20, 3:56 PM CST | Winter Storm Warning | DMX | 11 hr |
| Feb 25, 9:25 PM CST | Winter Weather Advisory | DMX | 18 hr |
| Mar 5, 9:16 PM CST | Dense Fog Advisory | DMX | 6 hr |
| Mar 7, 3:59 PM CST | Flash Flood Watch | DMX | 20 hr |
| Mar 8, 7:35 AM CDT | River Flood Warning | DMX | 4 days |
| Mar 10, 9:25 AM CDT | Dense Fog Advisory | DMX | 4 hr |
| Mar 10, 3:39 PM CDT | Wind Advisory | DMX | 15 hr |
| Mar 23, 3:50 AM CDT | Wind Advisory | DMX | 18 hr |
| Apr 4, 4:23 AM CDT | Winter Storm Warning | DMX | 39 hr |
| Apr 24, 3:18 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 24, 4:45 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Apr 24, 7:42 PM CDT | Mesoscale Discussion | SPC | 63 min |
| Apr 24, 9:40 PM CDT | Mesoscale Discussion | SPC | 65 min |
| Apr 26, 3:38 AM CDT | Flash Flood Watch | DMX | 24 hr |
| Apr 26, 3:51 PM CDT | Areal Flood Advisory | DMX | 3 hr |
| Apr 26, 4:08 PM CDT | Flash Flood Warning | DMX | 6 hr |
| Apr 26, 5:02 PM CDT | Tornado Watch | SPC | 6 hr |
| Apr 26, 6:08 PM CDT | Tornado Warning | DMX | 37 min |
| Apr 26, 6:14 PM CDT | Mesoscale Discussion | SPC | 61 min |
| Apr 26, 8:21 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Apr 26, 9:45 PM CDT | River Flood Warning | DMX | 59 hr |
| Apr 26, 9:45 PM CDT | River Flood Warning | DMX | 6 hr |
| Apr 26, 10:00 PM CDT | Areal Flood Warning | DMX | 13 hr |
| Apr 27, 7:35 PM CDT | River Flood Warning | DMX | 28 hr |
| Apr 30, 4:49 AM CDT | Dense Fog Advisory | DMX | 5 hr |
| May 8, 1:05 PM CDT | Mesoscale Discussion | SPC | 85 min |
| May 8, 1:21 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 8, 5:47 PM CDT | Mesoscale Discussion | SPC | 58 min |
| May 16, 3:41 AM CDT | Frost Advisory | DMX | 27 hr |
| May 27, 10:16 AM CDT | River Flood Warning | DMX | 34 hr |
| May 27, 10:16 AM CDT | River Flood Warning | DMX | 6 days |
| May 27, 10:16 AM CDT | River Flood Warning | DMX | 59 hr |
| Jun 7, 8:40 PM CDT | Areal Flood Advisory | DMX | 2 hr |
| Jun 17, 3:53 AM CDT | Dense Fog Advisory | DMX | 6 hr |
| Jun 17, 11:53 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 18, 6:41 AM CDT | Mesoscale Discussion | SPC | 94 min |
| Jun 18, 7:04 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jun 18, 3:15 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Jun 19, 2:13 AM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 19, 12:37 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 19, 3:13 PM CDT | Areal Flood Advisory | DMX | 59 hr |
| Jun 21, 12:33 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jun 21, 3:17 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 21, 3:41 PM CDT | Heat Advisory | DMX | 66 hr |
| Jun 21, 6:51 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 21, 7:49 PM CDT | Tornado Warning | DMX | 26 min |
| Jun 21, 9:06 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Jun 23, 11:31 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 23, 12:01 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 23, 3:25 PM CDT | Severe Thunderstorm Warning | DMX | 50 min |
| Jun 23, 4:01 PM CDT | Severe Thunderstorm Warning | DMX | 44 min |
| Jun 23, 4:09 PM CDT | Severe Thunderstorm Warning | DMX | 51 min |
| Jun 23, 4:12 PM CDT | Tornado Warning | DMX | 33 min |
| Jun 23, 4:42 PM CDT | Severe Thunderstorm Warning | DMX | 48 min |
| Jun 23, 4:58 PM CDT | Severe Thunderstorm Warning | DMX | 16 min |
| Jun 25, 12:14 PM CDT | Mesoscale Discussion | SPC | 61 min |
| Jun 25, 2:56 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Jul 10, 1:36 AM CDT | Mesoscale Discussion | SPC | 24 min |
| Jul 10, 2:54 AM CDT | Severe Thunderstorm Warning | DMX | 36 min |
| Jul 10, 3:27 AM CDT | Severe Thunderstorm Warning | DMX | 48 min |
| Jul 10, 4:28 AM CDT | Areal Flood Advisory | DMX | 4 hr |
| Jul 10, 4:58 AM CDT | Severe Thunderstorm Warning | DMX | 47 min |
| Jul 14, 8:13 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 14, 10:19 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jul 24, 9:51 AM CDT | Mesoscale Discussion | SPC | 54 min |
| Jul 24, 10:32 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 24, 2:24 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Aug 2, 11:37 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 7, 8:58 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Aug 7, 10:14 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 8, 1:29 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 9, 6:30 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 9, 6:54 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 9, 9:55 AM CDT | Mesoscale Discussion | SPC | 35 min |
| Aug 9, 10:38 AM CDT | Severe Thunderstorm Warning | DMX | 67 min |
| Aug 9, 11:05 AM CDT | Tornado Warning | DMX | 40 min |
| Aug 9, 11:46 AM CDT | Severe Thunderstorm Warning | DMX | 18 min |
| Aug 9, 1:40 PM CDT | Mesoscale Discussion | SPC | 35 min |
| Aug 9, 3:35 PM CDT | Flash Flood Watch | DMX | 5 hr |
| Aug 9, 3:44 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 10, 6:04 PM CDT | Areal Flood Advisory | DMX | 110 min |
| Aug 13, 2:44 AM CDT | Areal Flood Advisory | DMX | 5 hr |
| Aug 20, 1:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Sep 10, 6:30 AM CDT | Dense Fog Advisory | DMX | 4 hr |
| Sep 10, 8:40 PM CDT | Dense Fog Advisory | DMX | 13 hr |
| Sep 28, 9:38 AM CDT | Wind Advisory | DMX | 9 hr |
| Sep 29, 3:38 PM CDT | Frost Advisory | DMX | 16 hr |
| Oct 9, 4:07 AM CDT | Freeze Warning | DMX | 29 hr |
| Oct 29, 11:01 AM CDT | Flash Flood Watch | DMX | 11 hr |
| Oct 31, 8:00 PM CDT | River Flood Warning | DMX | 64 hr |
| Nov 1, 7:52 AM CST | River Flood Warning | DMX | 58 hr |
| Nov 20, 4:05 AM CST | Dense Fog Advisory | DMX | 6 hr |
| Nov 20, 9:27 PM CST | Dense Fog Advisory | DMX | 13 hr |
| Dec 6, 3:49 AM CST | Winter Weather Advisory | DMX | 24 hr |
| Dec 6, 3:34 PM CST | Winter Storm Watch | DMX | 24 hr |
| Dec 7, 3:42 PM CST | Blizzard Watch | DMX | 19 hr |
| Dec 7, 3:42 PM CST | Winter Storm Warning | DMX | 29 hr |
| Dec 8, 10:34 AM CST | Blizzard Warning | DMX | 31 hr |
| Dec 8, 11:22 AM CST | Mesoscale Discussion | SPC | 5 hr |
| Dec 8, 6:00 PM CST | Mesoscale Discussion | SPC | 5 hr |
| Dec 8, 9:38 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Dec 9, 10:22 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 9, 3:29 PM CST | Wind Chill Advisory | DMX | 21 hr |
| Dec 9, 3:29 PM CST | Winter Weather Advisory | DMX | 6 hr |
| Dec 13, 9:08 PM CST | Winter Weather Advisory | DMX | 15 hr |
| Dec 14, 3:30 PM CST | Wind Chill Advisory | DMX | 19 hr |
| Dec 21, 3:44 PM CST | Winter Storm Watch | DMX | 60 hr |
| Dec 22, 12:45 PM CST | Freezing Rain Advisory | DMX | 16 hr |
| Dec 23, 5:07 AM CST | Winter Storm Warning | DMX | 71 hr |
| Dec 23, 5:07 AM CST | Winter Weather Advisory | DMX | 23 hr |
| Dec 23, 12:21 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 23, 3:58 PM CST | Flood Watch | DMX | 12 hr |
| Dec 24, 3:45 PM CST | Winter Weather Advisory | DMX | 36 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.