Alert archive / Colorado / Washington County
Weather alerts in Washington County, Colorado, 2018
177 weather alerts in 2018, 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 2018. Tap one for its archive.
- Alerts
- 177
- Warnings
- 61
- Watches
- 30
- Advisories
- 27
- Busiest month
- June46 alerts
- Busiest day
- June 19, 201811 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
3 of 10 tornado warnings covering Washington County in 2018 had a tornado report inside them; 6 of 10 tornado reports fell inside a warning, on average 13 minutes after it went out.
Washington County, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 10 | 3 | 70% | 10 | 60% | 13 min |
| Severe thunderstorm warnings | 32 | 14 | 56% | 27 | 78% | 20 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 52 | 11 | 79% | 36 | 53% | 12 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 322 | 114 | 65% | 369 | 75% | 20 min |
| NWS Denver/Boulder, CO: flash flood warnings | 13 | 3 | 77% | 14 | 79% | 32 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 1, 5:26 PM MST | Wind Chill Advisory | BOU | 9 hr |
| Jan 15, 4:15 AM MST | Wind Chill Advisory | BOU | 29 hr |
| Jan 19, 1:54 PM MST | Winter Storm Watch | BOU | 16 hr |
| Jan 20, 5:24 AM MST | Winter Storm Warning | BOU | 36 hr |
| Jan 21, 4:15 AM MST | Blizzard Warning | BOU | 20 hr |
| Jan 21, 11:59 PM MST | Winter Weather Advisory | BOU | 5 hr |
| Feb 19, 11:42 PM MST | Wind Chill Advisory | BOU | 8 hr |
| Feb 22, 3:37 PM MST | Winter Storm Watch | BOU | 12 hr |
| Feb 23, 3:13 AM MST | Winter Weather Advisory | BOU | 27 hr |
| Mar 2, 3:51 AM MST | Red Flag Warning | BOU | 14 hr |
| Mar 2, 6:04 PM MST | Fire Weather Watch | BOU | 21 hr |
| Mar 3, 2:22 PM MST | High Wind Watch | BOU | 15 hr |
| Mar 3, 3:17 PM MST | Fire Weather Watch | BOU | 19 hr |
| Mar 3, 3:17 PM MST | Red Flag Warning | BOU | 28 hr |
| Mar 4, 5:22 AM MST | High Wind Warning | BOU | 36 hr |
| Mar 4, 9:49 AM MST | Red Flag Warning | BOU | 32 hr |
| Mar 15, 3:45 AM MDT | Winter Weather Advisory | BOU | 25 hr |
| Mar 17, 2:40 PM MDT | Winter Weather Advisory | BOU | 37 hr |
| Mar 23, 6:35 PM MDT | Special Weather Statement | BOU | 40 min |
| Mar 25, 7:31 PM MDT | Dense Fog Advisory | BOU | 13 hr |
| Apr 1, 2:29 PM MDT | High Wind Watch | BOU | 23 hr |
| Apr 2, 1:46 PM MDT | High Wind Warning | BOU | 21 hr |
| Apr 10, 3:44 AM MDT | Red Flag Warning | BOU | 39 hr |
| Apr 10, 3:44 AM MDT | Red Flag Warning | BOU | 65 hr |
| Apr 11, 2:59 PM MDT | High Wind Watch | BOU | 19 hr |
| Apr 12, 4:29 AM MDT | Winter Storm Watch | BOU | 5 hr |
| Apr 12, 9:51 AM MDT | Blizzard Warning | BOU | 43 hr |
| Apr 16, 2:16 PM MDT | High Wind Watch | BOU | 18 hr |
| Apr 17, 4:58 AM MDT | High Wind Warning | BOU | 16 hr |
| Apr 29, 2:53 PM MDT | Red Flag Warning | BOU | 28 hr |
| May 1, 1:01 PM MDT | Mesoscale Discussion | SPC | 119 min |
| May 1, 4:51 PM MDT | Severe Thunderstorm Warning | BOU | 39 min |
| May 10, 5:42 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| May 10, 6:06 PM MDT | Mesoscale Discussion | SPC | 114 min |
| May 11, 10:58 PM MDT | Dense Fog Advisory | BOU | 10 hr |
| May 13, 4:19 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 13, 4:40 PM MDT | Severe Thunderstorm Warning | BOU | 20 min |
| May 17, 4:19 PM MDT | Mesoscale Discussion | SPC | 116 min |
| May 18, 11:02 AM MDT | Flash Flood Watch | BOU | 30 hr |
| May 18, 3:06 PM MDT | Mesoscale Discussion | SPC | 114 min |
| May 18, 8:08 PM MDT | Mesoscale Discussion | SPC | 67 min |
| May 21, 3:00 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 27, 12:38 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| May 27, 1:13 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 27, 4:20 PM MDT | Severe Thunderstorm Warning | BOU | 40 min |
| May 27, 4:30 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 28, 1:12 PM MDT | Tornado Watch | SPC | 8 hr |
| May 28, 2:38 PM MDT | Flash Flood Watch | BOU | 6 hr |
| May 28, 4:18 PM MDT | Severe Thunderstorm Warning | BOU | 42 min |
| May 28, 4:54 PM MDT | Mesoscale Discussion | SPC | 96 min |
| May 28, 4:59 PM MDT | Severe Thunderstorm Warning | BOU | 46 min |
| May 28, 5:04 PM MDT | Tornado Warning | BOU | 26 min |
| May 28, 5:27 PM MDT | Tornado Warning | BOU | 33 min |
| May 29, 1:31 PM MDT | Severe Thunderstorm Warning | BOU | 26 min |
| May 29, 2:10 PM MDT | Mesoscale Discussion | SPC | 95 min |
| May 29, 5:02 PM MDT | Special Weather Statement | BOU | 43 min |
| May 30, 1:25 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 6, 2:49 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 6, 4:46 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 6, 9:30 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| Jun 6, 10:07 PM MDT | Areal Flood Advisory | BOU | 113 min |
| Jun 6, 10:21 PM MDT | Severe Thunderstorm Warning | BOU | 23 min |
| Jun 6, 10:58 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| Jun 6, 10:58 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 7, 12:06 AM MDT | Special Weather Statement | BOU | 39 min |
| Jun 7, 12:10 AM MDT | Areal Flood Advisory | BOU | 95 min |
| Jun 15, 4:47 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Jun 15, 4:52 PM MDT | Special Weather Statement | BOU | 23 min |
| Jun 17, 1:05 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jun 17, 1:35 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 17, 3:53 PM MDT | Mesoscale Discussion | SPC | 97 min |
| Jun 17, 4:32 PM MDT | Severe Thunderstorm Warning | BOU | 43 min |
| Jun 17, 4:58 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| Jun 17, 5:05 PM MDT | Tornado Warning | BOU | 25 min |
| Jun 17, 5:29 PM MDT | Tornado Warning | BOU | 20 min |
| Jun 17, 5:47 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Jun 18, 3:06 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 18, 6:37 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 18, 8:31 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Jun 18, 9:42 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Jun 18, 10:23 PM MDT | Severe Thunderstorm Warning | BOU | 37 min |
| Jun 18, 10:57 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jun 18, 11:58 PM MDT | Severe Thunderstorm Warning | BOU | 25 min |
| Jun 19, 11:48 AM MDT | Mesoscale Discussion | SPC | 117 min |
| Jun 19, 12:25 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 19, 1:54 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 19, 3:22 PM MDT | Severe Thunderstorm Warning | BOU | 53 min |
| Jun 19, 4:18 PM MDT | Severe Thunderstorm Warning | BOU | 57 min |
| Jun 19, 6:21 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jun 22, 11:53 AM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Jun 22, 12:19 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 22, 12:27 PM MDT | Special Weather Statement | BOU | 48 min |
| Jun 23, 1:02 PM MDT | Special Weather Statement | BOU | 43 min |
| Jun 24, 12:44 AM MDT | Special Weather Statement | BOU | 46 min |
| Jun 24, 12:47 AM MDT | Severe Thunderstorm Warning | BOU | 43 min |
| Jun 24, 1:16 AM MDT | Mesoscale Discussion | SPC | 59 min |
| Jun 24, 1:29 AM MDT | Severe Thunderstorm Warning | BOU | 31 min |
| Jun 24, 2:01 AM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jun 24, 12:51 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Jun 30, 1:03 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jun 30, 2:03 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 4:40 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 5:07 PM MDT | Severe Thunderstorm Warning | BOU | 21 min |
| Jul 2, 4:35 PM MDT | Special Weather Statement | BOU | 40 min |
| Jul 4, 1:51 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jul 4, 10:34 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Jul 5, 8:24 PM MDT | Special Weather Statement | BOU | 51 min |
| Jul 15, 10:46 PM MDT | Areal Flood Advisory | BOU | 2 hr |
| Jul 17, 3:09 PM MDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 17, 5:49 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Jul 17, 6:48 PM MDT | Severe Thunderstorm Warning | BOU | 16 min |
| Jul 22, 11:34 PM MDT | Special Weather Statement | BOU | 26 min |
| Jul 24, 8:12 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Jul 24, 8:41 PM MDT | Severe Thunderstorm Warning | BOU | 49 min |
| Jul 24, 8:47 PM MDT | Areal Flood Advisory | BOU | 2 hr |
| Jul 25, 10:41 AM MDT | Flash Flood Watch | BOU | 11 hr |
| Jul 25, 4:29 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 25, 6:40 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 25, 6:52 PM MDT | Areal Flood Advisory | BOU | 78 min |
| Jul 25, 7:25 PM MDT | Areal Flood Advisory | BOU | 39 min |
| Jul 25, 7:30 PM MDT | Areal Flood Advisory | BOU | 66 min |
| Jul 26, 12:49 PM MDT | Mesoscale Discussion | SPC | 56 min |
| Jul 26, 1:49 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 26, 6:07 PM MDT | Mesoscale Discussion | SPC | 113 min |
| Jul 27, 12:35 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jul 27, 1:04 PM MDT | Tornado Watch | SPC | 8 hr |
| Jul 27, 2:52 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Jul 27, 3:43 PM MDT | Tornado Warning | BOU | 32 min |
| Jul 27, 4:08 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Jul 27, 4:35 PM MDT | Tornado Warning | BOU | 25 min |
| Jul 27, 5:09 PM MDT | Areal Flood Advisory | BOU | 2 hr |
| Jul 29, 12:46 PM MDT | Mesoscale Discussion | SPC | 59 min |
| Jul 29, 1:07 PM MDT | Tornado Watch | SPC | 8 hr |
| Jul 29, 4:10 PM MDT | Tornado Warning | BOU | 35 min |
| Jul 29, 4:37 PM MDT | Tornado Warning | BOU | 23 min |
| Jul 29, 5:01 PM MDT | Tornado Warning | BOU | 44 min |
| Jul 29, 5:23 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Jul 29, 5:32 PM MDT | Tornado Warning | BOU | 28 min |
| Jul 29, 5:57 PM MDT | Severe Thunderstorm Warning | BOU | 23 min |
| Jul 29, 6:25 PM MDT | Severe Thunderstorm Warning | BOU | 50 min |
| Aug 6, 2:37 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 6, 5:24 PM MDT | Mesoscale Discussion | SPC | 66 min |
| Aug 6, 8:06 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Aug 7, 5:42 PM MDT | Areal Flood Advisory | BOU | 46 min |
| Aug 7, 6:07 PM MDT | Severe Thunderstorm Warning | BOU | 38 min |
| Aug 7, 7:57 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 8, 5:56 AM MDT | Special Weather Statement | BOU | 34 min |
| Aug 17, 5:40 PM MDT | Special Weather Statement | BOU | 50 min |
| Aug 17, 5:42 PM MDT | Areal Flood Advisory | BOU | 93 min |
| Aug 17, 5:45 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Aug 17, 6:32 PM MDT | Flash Flood Warning | BOU | 3 hr |
| Aug 25, 2:42 PM MDT | Special Weather Statement | BOU | 48 min |
| Aug 25, 3:26 PM MDT | Special Weather Statement | BOU | 49 min |
| Aug 25, 4:01 PM MDT | Areal Flood Advisory | BOU | 89 min |
| Aug 25, 6:26 PM MDT | Special Weather Statement | BOU | 34 min |
| Aug 25, 7:00 PM MDT | Areal Flood Advisory | BOU | 90 min |
| Aug 26, 3:58 AM MDT | Fire Weather Watch | BOU | 12 hr |
| Aug 26, 3:35 PM MDT | Red Flag Warning | BOU | 26 hr |
| Aug 31, 6:13 PM MDT | Special Weather Statement | GLD | 47 min |
| Sep 1, 4:37 PM MDT | Mesoscale Discussion | SPC | 113 min |
| Sep 9, 7:13 PM MDT | Special Weather Statement | BOU | 32 min |
| Sep 11, 6:01 PM MDT | Special Weather Statement | GLD | 29 min |
| Sep 19, 7:58 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| Sep 24, 2:24 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Oct 7, 2:30 PM MDT | Freeze Watch | BOU | 25 hr |
| Oct 8, 3:01 PM MDT | Freeze Warning | BOU | 13 hr |
| Oct 9, 4:25 AM MDT | Freeze Warning | BOU | 30 hr |
| Oct 10, 2:27 PM MDT | Freeze Warning | BOU | 19 hr |
| Oct 12, 2:20 PM MDT | Winter Weather Advisory | BOU | 49 hr |
| Nov 7, 3:47 AM MST | Winter Weather Advisory | BOU | 22 hr |
| Nov 16, 10:36 AM MST | Winter Weather Advisory | BOU | 34 hr |
| Nov 22, 3:49 PM MST | Winter Weather Advisory | BOU | 61 hr |
| Nov 24, 5:39 AM MST | High Wind Warning | BOU | 19 hr |
| Dec 17, 3:32 PM MST | High Wind Watch | BOU | 18 hr |
| Dec 18, 9:57 AM MST | High Wind Warning | BOU | 31 hr |
| Dec 25, 4:53 AM MST | Winter Storm Watch | BOU | 23 hr |
| Dec 26, 4:21 AM MST | Winter Weather Advisory | BOU | 14 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 | 32 |
| Tornado Warning | 10 |
| Severe Thunderstorm Watch | 9 |
| Tornado Watch | 5 |
| Mesoscale Discussion | 41 |
| Special Weather Statement | 18 |
| Flooding | |
| Flash Flood Warning | 1 |
| Flash Flood Watch | 3 |
| Areal Flood Advisory | 13 |
| Winter | |
| Blizzard Warning | 2 |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 9 |
| Cold | |
| Freeze Warning | 3 |
| Freeze Watch | 1 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 5 |
| High Wind Watch | 5 |
| Fire | |
| Red Flag Warning | 7 |
| Fire Weather Watch | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20172019
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.