Alert archive / Iowa / Washington County
Weather alerts in Washington County, Iowa, 2009
146 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Washington County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 146
- Warnings
- 44
- Watches
- 28
- Advisories
- 30
- Busiest month
- June42 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.
1 of 3 tornado warnings covering Washington County in 2009 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 23 minutes after it went out.
Washington County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 3 | 1 | 67% | 1 | 100% | 23 min |
| Severe thunderstorm warnings | 12 | 10 | 17% | 6 | 67% | 26 min |
| Flash flood warnings | 4 | 2 | 50% | 4 | 100% | 174 min |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Quad Cities, IA: tornado warnings | 17 | 6 | 65% | 18 | 78% | 11 min |
| NWS Quad Cities, IA: severe thunderstorm warnings | 117 | 90 | 23% | 347 | 88% | 33 min |
| NWS Quad Cities, IA: flash flood warnings | 49 | 37 | 24% | 86 | 84% | 91 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, 3:46 PM CST | Dense Fog Advisory | DVN | 10 hr |
| Jan 8, 3:11 PM CST | Winter Weather Advisory | DVN | 48 hr |
| Jan 11, 3:24 PM CST | Winter Storm Watch | DVN | 12 hr |
| Jan 12, 3:24 AM CST | Blizzard Watch | DVN | 10 hr |
| Jan 12, 3:24 AM CST | Winter Weather Advisory | DVN | 23 hr |
| Jan 12, 1:06 PM CST | Blizzard Warning | DVN | 11 hr |
| Jan 12, 6:27 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Jan 13, 2:45 AM CST | Wind Chill Advisory | DVN | 12 hr |
| Jan 13, 3:15 AM CST | Winter Weather Advisory | DVN | 36 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, 3:45 AM CST | Wind Chill Warning | DVN | 56 hr |
| Jan 17, 4:48 PM CST | Winter Weather Advisory | DVN | 7 hr |
| Feb 2, 3:16 PM CST | Wind Chill Advisory | DVN | 19 hr |
| Feb 7, 7:56 PM CST | River Flood Warning | DVN | 13 hr |
| Feb 10, 9:49 AM CST | River Flood Warning | DVN | 56 hr |
| Feb 20, 4:17 AM CST | Winter Weather Advisory | DVN | 35 hr |
| Feb 26, 9:26 AM CST | Mesoscale Discussion | SPC | 2 hr |
| Feb 26, 10:09 AM CST | Dense Fog Advisory | DVN | 4 hr |
| Mar 6, 11:21 AM CST | Flash Flood Watch | DVN | 51 hr |
| Mar 7, 8:34 PM CST | Severe Thunderstorm Warning | DVN | 23 min |
| Mar 8, 3:50 AM CDT | River Flood Warning | DVN | 5 days |
| Mar 8, 5:29 AM CDT | River Flood Warning | DVN | 4 days |
| Mar 8, 5:38 AM CDT | Areal Flood Warning | DVN | 15 hr |
| Mar 9, 4:19 AM CDT | Flash Flood Watch | DVN | 32 hr |
| Mar 9, 11:45 PM CDT | Areal Flood Warning | DVN | 12 hr |
| Mar 10, 4:22 AM CDT | Wind Advisory | DVN | 27 hr |
| Mar 10, 9:25 AM CDT | Dense Fog Advisory | DVN | 4 hr |
| Mar 23, 3:39 PM CDT | Wind Advisory | DVN | 4 hr |
| Mar 27, 11:32 AM CDT | Winter Storm Watch | DVN | 16 hr |
| Mar 28, 3:33 AM CDT | Winter Storm Warning | DVN | 24 hr |
| Apr 4, 3:43 PM CDT | Winter Weather Advisory | DVN | 28 hr |
| Apr 21, 11:03 AM CDT | Wind Advisory | DVN | 8 hr |
| Apr 23, 11:42 PM CDT | Dense Fog Advisory | DVN | 8 hr |
| Apr 25, 5:32 PM CDT | Mesoscale Discussion | SPC | 73 min |
| Apr 25, 8:25 PM CDT | Special Weather Statement | DVN | 50 min |
| Apr 26, 3:04 AM CDT | Flash Flood Watch | DVN | 24 hr |
| Apr 26, 6:14 PM CDT | Mesoscale Discussion | SPC | 61 min |
| Apr 26, 8:21 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Apr 26, 11:01 PM CDT | Special Weather Statement | DVN | 119 min |
| Apr 26, 11:15 PM CDT | Mesoscale Discussion | SPC | 60 min |
| May 8, 1:05 PM CDT | Mesoscale Discussion | SPC | 85 min |
| May 8, 5:47 PM CDT | Mesoscale Discussion | SPC | 58 min |
| May 8, 6:10 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| May 8, 6:18 PM CDT | Severe Thunderstorm Warning | DVN | 57 min |
| May 8, 7:07 PM CDT | Severe Thunderstorm Warning | DVN | 41 min |
| May 13, 2:39 PM CDT | Tornado Watch | SPC | 7 hr |
| May 13, 5:47 PM CDT | Mesoscale Discussion | SPC | 88 min |
| May 13, 6:19 PM CDT | Special Weather Statement | DVN | 86 min |
| May 13, 7:05 PM CDT | Mesoscale Discussion | SPC | 85 min |
| May 14, 3:19 PM CDT | Flash Flood Watch | DVN | 31 hr |
| May 15, 10:10 AM CDT | River Flood Warning | DVN | 11 hr |
| May 15, 10:10 AM CDT | River Flood Warning | DVN | 48 hr |
| May 16, 3:53 AM CDT | Frost Advisory | DVN | 28 hr |
| Jun 1, 3:29 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 7, 4:45 AM CDT | Mesoscale Discussion | SPC | 30 min |
| Jun 7, 5:31 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 7, 8:49 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jun 7, 11:09 PM CDT | Severe Thunderstorm Warning | DVN | 51 min |
| Jun 16, 4:52 PM CDT | Special Weather Statement | DVN | 53 min |
| Jun 16, 5:52 PM CDT | Special Weather Statement | DVN | 68 min |
| Jun 17, 4:30 AM CDT | Dense Fog Advisory | DVN | 4 hr |
| Jun 17, 11:53 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 18, 1:47 AM CDT | Severe Thunderstorm Warning | DVN | 58 min |
| Jun 18, 3:20 AM CDT | Mesoscale Discussion | SPC | 85 min |
| Jun 18, 9:39 AM CDT | River Flood Warning | DVN | 17 hr |
| Jun 18, 10:11 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 18, 1:17 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Jun 19, 6:58 AM CDT | Mesoscale Discussion | SPC | 62 min |
| Jun 19, 7:14 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 19, 12:37 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jun 19, 1:54 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jun 19, 2:24 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 19, 4:24 PM CDT | Severe Thunderstorm Warning | DVN | 54 min |
| Jun 19, 4:42 PM CDT | Severe Thunderstorm Warning | DVN | 46 min |
| Jun 19, 5:03 PM CDT | Severe Thunderstorm Warning | DVN | 57 min |
| Jun 20, 4:15 AM CDT | River Flood Warning | DVN | 3 days |
| Jun 21, 9:40 AM CDT | River Flood Warning | DVN | 48 hr |
| Jun 21, 3:17 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 21, 8:06 PM CDT | Tornado Warning | DVN | 39 min |
| Jun 21, 8:38 PM CDT | Tornado Warning | DVN | 52 min |
| Jun 21, 9:13 PM CDT | Flash Flood Warning | DVN | 6 hr |
| Jun 21, 9:21 PM CDT | Tornado Warning | DVN | 54 min |
| Jun 22, 12:07 PM CDT | Heat Advisory | DVN | 7 hr |
| Jun 22, 3:25 PM CDT | Heat Advisory | DVN | 29 hr |
| Jun 23, 3:21 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Jun 23, 3:28 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 23, 5:19 PM CDT | Severe Thunderstorm Warning | DVN | 71 min |
| Jun 23, 6:06 PM CDT | Severe Thunderstorm Warning | DVN | 69 min |
| Jun 23, 11:12 PM CDT | River Flood Warning | DVN | 29 hr |
| Jun 24, 3:57 AM CDT | Heat Advisory | DVN | 11 hr |
| Jun 25, 10:40 AM CDT | Heat Advisory | DVN | 9 hr |
| Jun 25, 12:48 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 25, 5:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 27, 1:19 PM CDT | Mesoscale Discussion | SPC | 56 min |
| Jun 27, 2:41 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 7, 4:42 PM CDT | Special Weather Statement | DVN | 108 min |
| Jul 10, 10:24 AM CDT | Special Weather Statement | DVN | 66 min |
| Jul 15, 5:06 AM CDT | Special Weather Statement | DVN | 69 min |
| Jul 15, 5:50 AM CDT | Special Weather Statement | DVN | 85 min |
| Jul 15, 7:02 AM CDT | Special Weather Statement | DVN | 58 min |
| Jul 23, 5:30 PM CDT | Special Weather Statement | DVN | 60 min |
| Jul 24, 1:12 PM CDT | Tornado Watch | SPC | 4 hr |
| Jul 24, 3:52 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 24, 5:02 PM CDT | Tornado Watch | SPC | 6 hr |
| Jul 24, 7:20 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Jul 24, 9:18 PM CDT | Severe Thunderstorm Warning | DVN | 57 min |
| Jul 24, 9:22 PM CDT | Mesoscale Discussion | SPC | 53 min |
| Aug 8, 2:43 AM CDT | Heat Advisory | DVN | 40 hr |
| Aug 9, 9:55 AM CDT | Mesoscale Discussion | SPC | 35 min |
| Aug 9, 5:52 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 9, 7:34 PM CDT | Severe Thunderstorm Warning | DVN | 56 min |
| Aug 9, 8:30 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Aug 26, 9:10 AM CDT | Flash Flood Watch | DVN | 42 hr |
| Aug 26, 9:17 AM CDT | Flash Flood Warning | DVN | 6 hr |
| Aug 27, 12:57 AM CDT | Flash Flood Warning | DVN | 6 hr |
| Aug 27, 3:59 AM CDT | River Flood Warning | DVN | 4 days |
| Aug 27, 9:52 AM CDT | River Flood Warning | DVN | 49 hr |
| Aug 27, 6:31 PM CDT | Flash Flood Warning | DVN | 6 hr |
| Aug 28, 12:03 AM CDT | Areal Flood Warning | DVN | 12 hr |
| Sep 9, 9:22 PM CDT | Dense Fog Advisory | DVN | 13 hr |
| Sep 10, 3:10 PM CDT | Dense Fog Advisory | DVN | 18 hr |
| Sep 23, 4:12 AM CDT | Dense Fog Advisory | DVN | 6 hr |
| Oct 9, 4:02 AM CDT | Freeze Warning | DVN | 29 hr |
| Oct 23, 4:38 AM CDT | River Flood Warning | DVN | 48 hr |
| Oct 29, 2:46 PM CDT | Flash Flood Watch | DVN | 13 hr |
| Oct 29, 7:30 PM CDT | River Flood Warning | DVN | 4 days |
| Oct 29, 8:44 PM CDT | River Flood Warning | DVN | 50 hr |
| Nov 16, 4:01 AM CST | Flood Watch | DVN | 33 hr |
| Nov 20, 9:28 PM CST | Dense Fog Advisory | DVN | 13 hr |
| Dec 6, 3:14 PM CST | Winter Storm Watch | DVN | 25 hr |
| Dec 7, 3:46 AM CST | Blizzard Watch | DVN | 34 hr |
| Dec 7, 3:45 PM CST | Winter Storm Warning | DVN | 50 hr |
| Dec 8, 11:22 AM CST | Mesoscale Discussion | SPC | 5 hr |
| Dec 8, 1:55 PM CST | Blizzard Warning | DVN | 28 hr |
| Dec 8, 2:31 PM CST | Special Weather Statement | DVN | 3 hr |
| Dec 8, 3:53 PM CST | Special Weather Statement | DVN | 2 hr |
| Dec 8, 6:00 PM CST | Mesoscale Discussion | SPC | 5 hr |
| Dec 9, 10:22 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 9, 3:41 PM CST | Winter Weather Advisory | DVN | 12 hr |
| Dec 10, 3:16 AM CST | Wind Chill Advisory | DVN | 9 hr |
| Dec 12, 2:52 PM CST | Freezing Rain Advisory | DVN | 17 hr |
| Dec 14, 3:32 AM CST | Dense Fog Advisory | DVN | 8 hr |
| Dec 21, 3:18 PM CST | Winter Storm Watch | DVN | 3 days |
| Dec 22, 3:47 PM CST | Flood Watch | DVN | 62 hr |
| Dec 25, 10:10 AM CST | River Flood Warning | DVN | 42 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.