Alert archive / Colorado / Washington County
Weather alerts in Washington County, Colorado, 2009
184 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
- 184
- Warnings
- 68
- Watches
- 33
- Advisories
- 15
- Busiest month
- July54 alerts
- Busiest day
- July 6, 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 6 tornado warnings covering Washington County in 2009 had a tornado report inside them.
Washington County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 6 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 43 | 16 | 63% | 23 | 87% | 14 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 81 | 16 | 80% | 45 | 44% | 12 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 279 | 128 | 54% | 321 | 70% | 17 min |
| NWS Denver/Boulder, CO: flash flood warnings | 19 | 6 | 68% | 13 | 62% | 43 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 12, 4:13 AM MST | High Wind Warning | BOU | 11 hr |
| Jan 19, 10:21 AM MST | Red Flag Warning | BOU | 7 hr |
| Feb 5, 2:08 PM MST | Fire Weather Watch | BOU | 15 hr |
| Feb 5, 2:08 PM MST | Red Flag Warning | BOU | 29 hr |
| Feb 11, 2:42 PM MST | Winter Storm Watch | BOU | 19 hr |
| Feb 12, 9:44 AM MST | Winter Storm Warning | BOU | 25 hr |
| Feb 25, 5:42 AM MST | Red Flag Warning | BOU | 12 hr |
| Mar 3, 3:01 PM MST | Fire Weather Watch | BOU | 24 hr |
| Mar 4, 2:42 PM MST | Red Flag Warning | BOU | 27 hr |
| Mar 21, 2:59 AM MDT | Dense Fog Advisory | BOU | 7 hr |
| Mar 21, 4:45 PM MDT | Severe Thunderstorm Warning | BOU | 60 min |
| Mar 21, 5:23 PM MDT | Mesoscale Discussion | SPC | 97 min |
| Mar 21, 6:00 PM MDT | Severe Thunderstorm Warning | BOU | 60 min |
| Mar 21, 6:43 PM MDT | Tornado Warning | BOU | 47 min |
| Mar 22, 4:38 AM MDT | Winter Weather Advisory | BOU | 33 hr |
| Mar 23, 1:38 PM MDT | High Wind Warning | BOU | 28 hr |
| Mar 25, 11:47 AM MDT | Winter Storm Warning | BOU | 29 hr |
| Mar 26, 2:57 AM MDT | Blizzard Warning | BOU | 33 hr |
| Mar 26, 6:55 AM MDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 30, 5:32 PM MDT | High Wind Warning | BOU | 4 hr |
| Apr 2, 4:20 AM MDT | Winter Storm Watch | BOU | 32 hr |
| Apr 3, 11:50 AM MDT | Blizzard Warning | BOU | 42 hr |
| Apr 15, 3:41 PM MDT | Mesoscale Discussion | SPC | 94 min |
| Apr 16, 1:10 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Apr 16, 2:22 PM MDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Apr 16, 5:01 PM MDT | Mesoscale Discussion | SPC | 59 min |
| Apr 28, 4:45 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| May 25, 6:25 PM MDT | Special Weather Statement | BOU | 50 min |
| May 30, 4:18 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jun 4, 1:27 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 4, 5:16 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jun 5, 2:18 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jun 5, 2:48 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 5, 5:37 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Jun 7, 10:44 AM MDT | Mesoscale Discussion | SPC | 61 min |
| Jun 7, 11:02 AM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 7, 2:30 PM MDT | Mesoscale Discussion | SPC | 60 min |
| Jun 7, 3:43 PM MDT | Tornado Warning | BOU | 47 min |
| Jun 7, 4:05 PM MDT | Tornado Warning | BOU | 40 min |
| Jun 8, 2:03 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jun 10, 6:47 PM MDT | Areal Flood Advisory | BOU | 88 min |
| Jun 11, 2:00 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 11, 3:36 PM MDT | Severe Thunderstorm Warning | BOU | 54 min |
| Jun 11, 11:59 PM MDT | Severe Thunderstorm Warning | BOU | 61 min |
| Jun 12, 4:04 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 12, 6:56 PM MDT | Mesoscale Discussion | SPC | 64 min |
| Jun 13, 1:56 PM MDT | Tornado Watch | SPC | 9 hr |
| Jun 13, 6:42 PM MDT | Mesoscale Discussion | SPC | 63 min |
| Jun 13, 8:31 PM MDT | Severe Thunderstorm Warning | BOU | 17 min |
| Jun 13, 9:25 PM MDT | Areal Flood Advisory | BOU | 95 min |
| Jun 14, 1:06 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jun 14, 1:50 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 14, 4:26 PM MDT | Severe Thunderstorm Warning | BOU | 49 min |
| Jun 14, 4:55 PM MDT | Severe Thunderstorm Warning | BOU | 28 min |
| Jun 14, 5:35 PM MDT | Severe Thunderstorm Warning | BOU | 43 min |
| Jun 14, 6:09 PM MDT | Severe Thunderstorm Warning | BOU | 10 min |
| Jun 15, 2:34 PM MDT | Tornado Watch | SPC | 8 hr |
| Jun 17, 1:29 PM MDT | Mesoscale Discussion | SPC | 61 min |
| Jun 17, 2:30 PM MDT | Tornado Watch | SPC | 8 hr |
| Jun 17, 4:43 PM MDT | Mesoscale Discussion | SPC | 92 min |
| Jun 17, 5:18 PM MDT | Severe Thunderstorm Warning | BOU | 42 min |
| Jun 17, 5:59 PM MDT | Severe Thunderstorm Warning | BOU | 61 min |
| Jun 23, 2:51 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 23, 6:13 PM MDT | Mesoscale Discussion | SPC | 62 min |
| Jun 25, 1:06 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jun 25, 1:30 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 25, 4:22 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Jun 25, 5:50 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Jun 25, 6:36 PM MDT | Areal Flood Advisory | BOU | 84 min |
| Jun 26, 2:23 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Jun 26, 2:38 PM MDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 26, 3:50 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 26, 4:37 PM MDT | Severe Thunderstorm Warning | BOU | 53 min |
| Jul 1, 6:38 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 1, 8:19 PM MDT | Special Weather Statement | BOU | 26 min |
| Jul 1, 8:52 PM MDT | Special Weather Statement | BOU | 23 min |
| Jul 1, 9:19 PM MDT | Mesoscale Discussion | SPC | 56 min |
| Jul 2, 6:29 PM MDT | Mesoscale Discussion | SPC | 61 min |
| Jul 2, 6:36 PM MDT | Severe Thunderstorm Warning | BOU | 24 min |
| Jul 3, 2:48 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 3, 5:25 PM MDT | Mesoscale Discussion | SPC | 65 min |
| Jul 3, 8:43 PM MDT | Mesoscale Discussion | SPC | 32 min |
| Jul 3, 9:45 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| Jul 3, 10:26 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jul 5, 6:06 PM MDT | Severe Thunderstorm Warning | BOU | 54 min |
| Jul 5, 6:15 PM MDT | Mesoscale Discussion | SPC | 60 min |
| Jul 5, 6:21 PM MDT | Areal Flood Advisory | BOU | 84 min |
| Jul 5, 7:12 PM MDT | Tornado Warning | BOU | 48 min |
| Jul 5, 7:27 PM MDT | Areal Flood Advisory | BOU | 69 min |
| Jul 6, 12:22 PM MDT | Mesoscale Discussion | SPC | 113 min |
| Jul 6, 1:40 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jul 6, 2:07 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 6, 5:35 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Jul 6, 6:25 PM MDT | Severe Thunderstorm Warning | BOU | 65 min |
| Jul 6, 6:53 PM MDT | Severe Thunderstorm Warning | BOU | 52 min |
| Jul 6, 7:07 PM MDT | Mesoscale Discussion | SPC | 23 min |
| Jul 6, 7:31 PM MDT | Severe Thunderstorm Warning | BOU | 44 min |
| Jul 11, 3:35 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Jul 11, 3:56 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jul 11, 4:48 PM MDT | Severe Thunderstorm Warning | BOU | 42 min |
| Jul 11, 5:30 PM MDT | Severe Thunderstorm Warning | BOU | 60 min |
| Jul 11, 5:51 PM MDT | Flash Flood Warning | BOU | 2 hr |
| Jul 11, 7:46 PM MDT | Mesoscale Discussion | SPC | 59 min |
| Jul 12, 2:05 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jul 12, 4:22 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jul 12, 5:27 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jul 12, 6:12 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Jul 12, 6:56 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Jul 13, 12:07 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Jul 13, 1:45 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 14, 6:18 PM MDT | Special Weather Statement | BOU | 27 min |
| Jul 14, 6:49 PM MDT | Special Weather Statement | BOU | 26 min |
| Jul 15, 6:27 PM MDT | Special Weather Statement | BOU | 48 min |
| Jul 17, 12:06 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Jul 17, 12:59 PM MDT | Tornado Watch | SPC | 6 hr |
| Jul 17, 4:28 PM MDT | Tornado Warning | BOU | 26 min |
| Jul 17, 5:00 PM MDT | Special Weather Statement | BOU | 45 min |
| Jul 17, 6:32 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 18, 2:12 AM MDT | Mesoscale Discussion | SPC | 93 min |
| Jul 18, 4:07 AM MDT | Severe Thunderstorm Warning | BOU | 24 min |
| Jul 21, 8:37 PM MDT | Severe Thunderstorm Warning | BOU | 38 min |
| Jul 21, 9:15 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Jul 22, 1:16 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jul 22, 1:55 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 22, 5:47 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Jul 23, 1:25 PM MDT | Mesoscale Discussion | SPC | 65 min |
| Jul 23, 3:45 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| Aug 3, 4:19 PM MDT | Severe Thunderstorm Warning | BOU | 56 min |
| Aug 5, 3:51 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Aug 5, 4:15 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 5, 7:26 PM MDT | Mesoscale Discussion | SPC | 64 min |
| Aug 5, 10:09 PM MDT | Mesoscale Discussion | SPC | 66 min |
| Aug 6, 5:28 PM MDT | Mesoscale Discussion | SPC | 92 min |
| Aug 6, 7:06 PM MDT | Severe Thunderstorm Warning | BOU | 54 min |
| Aug 7, 5:37 PM MDT | Mesoscale Discussion | SPC | 113 min |
| Aug 8, 3:34 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Aug 8, 10:57 PM MDT | Tornado Warning | BOU | 48 min |
| Aug 10, 12:52 AM MDT | Severe Thunderstorm Warning | BOU | 38 min |
| Aug 10, 1:29 AM MDT | Mesoscale Discussion | SPC | 61 min |
| Aug 10, 1:49 AM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 10, 5:02 AM MDT | Mesoscale Discussion | SPC | 118 min |
| Aug 10, 1:07 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Aug 10, 4:38 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Aug 10, 4:43 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 10, 7:14 PM MDT | Mesoscale Discussion | SPC | 91 min |
| Aug 10, 7:56 PM MDT | Severe Thunderstorm Warning | BOU | 42 min |
| Aug 10, 8:11 PM MDT | Severe Thunderstorm Warning | BOU | 26 min |
| Aug 15, 1:07 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Aug 15, 4:10 PM MDT | Mesoscale Discussion | SPC | 65 min |
| Aug 16, 6:12 PM MDT | Mesoscale Discussion | SPC | 93 min |
| Aug 17, 5:46 PM MDT | Severe Thunderstorm Warning | BOU | 51 min |
| Aug 17, 6:32 PM MDT | Severe Thunderstorm Warning | BOU | 43 min |
| Aug 17, 7:14 PM MDT | Severe Thunderstorm Warning | BOU | 46 min |
| Aug 17, 7:55 PM MDT | Severe Thunderstorm Warning | BOU | 27 min |
| Aug 18, 12:29 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 25, 5:18 PM MDT | Areal Flood Advisory | BOU | 117 min |
| Aug 25, 5:19 PM MDT | Areal Flood Advisory | BOU | 116 min |
| Aug 29, 6:37 PM MDT | Severe Thunderstorm Warning | BOU | 53 min |
| Sep 8, 4:17 PM MDT | Severe Thunderstorm Warning | BOU | 28 min |
| Sep 8, 5:15 PM MDT | Severe Thunderstorm Warning | BOU | 60 min |
| Sep 8, 6:10 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 8, 6:54 PM MDT | Severe Thunderstorm Warning | BOU | 36 min |
| Sep 8, 7:16 PM MDT | Severe Thunderstorm Warning | BOU | 44 min |
| Sep 8, 7:32 PM MDT | Areal Flood Advisory | BOU | 118 min |
| Sep 24, 10:21 AM MDT | Special Weather Statement | BOU | 24 min |
| Sep 29, 3:27 PM MDT | Fire Weather Watch | BOU | 14 hr |
| Sep 30, 5:00 AM MDT | Red Flag Warning | BOU | 15 hr |
| Oct 1, 3:05 AM MDT | High Wind Warning | BOU | 17 hr |
| Oct 2, 3:38 PM MDT | Freeze Warning | BOU | 16 hr |
| Oct 9, 10:20 PM MDT | Mesoscale Discussion | SPC | 4 hr |
| Oct 20, 3:11 PM MDT | Winter Weather Advisory | BOU | 36 hr |
| Oct 27, 3:26 AM MDT | Winter Storm Watch | BOU | 25 hr |
| Oct 27, 3:26 AM MDT | Winter Storm Warning | BOU | 69 hr |
| Oct 28, 9:56 PM MDT | Mesoscale Discussion | SPC | 4 hr |
| Oct 29, 12:59 PM MDT | Blizzard Warning | BOU | 16 hr |
| Oct 29, 5:57 PM MDT | Mesoscale Discussion | SPC | 4 hr |
| Nov 13, 5:06 AM MST | Winter Storm Watch | BOU | 34 hr |
| Nov 14, 10:57 AM MST | Winter Storm Warning | BOU | 26 hr |
| Dec 7, 5:21 AM MST | Winter Weather Advisory | BOU | 47 hr |
| Dec 8, 12:53 PM MST | Wind Chill Advisory | BOU | 9 hr |
| Dec 21, 3:56 AM MST | Winter Storm Watch | BOU | 16 hr |
| Dec 21, 7:53 PM MST | Winter Storm Warning | BOU | 43 hr |
| Dec 21, 7:53 PM MST | Winter Weather Advisory | BOU | 61 hr |
| Dec 24, 3:52 PM MST | Winter Weather Advisory | BOU | 49 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 | 43 |
| Tornado Warning | 6 |
| Severe Thunderstorm Watch | 17 |
| Tornado Watch | 8 |
| Mesoscale Discussion | 60 |
| Special Weather Statement | 8 |
| Flooding | |
| Flash Flood Warning | 1 |
| Areal Flood Advisory | 8 |
| Winter | |
| Blizzard Warning | 3 |
| Winter Storm Warning | 5 |
| Winter Storm Watch | 5 |
| Winter Weather Advisory | 5 |
| Cold | |
| Freeze Warning | 1 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 4 |
| Fire | |
| Red Flag Warning | 5 |
| Fire Weather Watch | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
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.