Alert archive / Colorado / Broomfield County
Weather alerts in Broomfield County, Colorado, 2018
96 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Broomfield County and its neighbors
Each county as a circle sized by its count in 2018. Tap one for its archive.
- Alerts
- 96
- Warnings
- 24
- Watches
- 16
- Advisories
- 16
- Busiest month
- July17 alerts
- Busiest day
- June 19, 20189 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Broomfield County, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 10 | 7 | 30% | 3 | 100% | 13 min |
| Flash flood warnings | 0 | 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 15, 6:46 AM MST | Winter Weather Advisory | BOU | 6 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 |
| Feb 9, 5:37 PM MST | Dense Fog Advisory | BOU | 3 hr |
| Feb 18, 2:01 PM MST | Winter Weather Advisory | BOU | 34 hr |
| Mar 3, 3:17 PM MST | Fire Weather Watch | BOU | 5 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 Watch | BOU | 9 hr |
| Mar 4, 9:49 AM MST | Red Flag Warning | BOU | 32 hr |
| Mar 17, 2:40 PM MDT | Winter Weather Advisory | BOU | 37 hr |
| Mar 25, 7:31 PM MDT | Dense Fog Advisory | BOU | 13 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 16, 3:45 AM MDT | Red Flag Warning | BOU | 42 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 18, 8:27 PM MDT | Red Flag Warning | BOU | 24 hr |
| May 1, 1:01 PM MDT | Mesoscale Discussion | SPC | 119 min |
| May 11, 12:00 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 11, 10:58 PM MDT | Dense Fog Advisory | BOU | 10 hr |
| May 12, 7:10 PM MDT | Special Weather Statement | BOU | 35 min |
| May 13, 4:19 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 13, 9:07 PM MDT | Special Weather Statement | BOU | 38 min |
| May 14, 12:38 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 18, 11:02 AM MDT | Flash Flood Watch | BOU | 30 hr |
| May 18, 2:59 PM MDT | Special Weather Statement | BOU | 46 min |
| May 18, 3:06 PM MDT | Mesoscale Discussion | SPC | 114 min |
| May 18, 5:28 PM MDT | Special Weather Statement | BOU | 47 min |
| May 22, 4:56 PM MDT | Severe Thunderstorm Warning | BOU | 26 min |
| May 23, 1:00 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 27, 4:30 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 28, 1:39 PM MDT | Mesoscale Discussion | SPC | 96 min |
| May 28, 2:01 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 18, 3:06 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 18, 6:12 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Jun 18, 7:19 PM MDT | Special Weather Statement | BOU | 26 min |
| Jun 18, 7:24 PM MDT | Severe Thunderstorm Warning | BOU | 51 min |
| Jun 18, 8:16 PM MDT | Severe Thunderstorm Warning | BOU | 29 min |
| Jun 18, 8:31 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Jun 18, 8:44 PM MDT | Severe Thunderstorm Warning | BOU | 46 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, 6:21 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jun 24, 12:01 PM MDT | Special Weather Statement | BOU | 44 min |
| Jun 27, 6:01 PM MDT | Special Weather Statement | BOU | 44 min |
| Jun 27, 6:10 PM MDT | Special Weather Statement | BOU | 50 min |
| Jun 30, 1:03 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jul 4, 1:51 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jul 15, 4:14 AM MDT | Flash Flood Watch | BOU | 16 hr |
| Jul 16, 3:36 AM MDT | Dense Fog Advisory | BOU | 3 hr |
| Jul 23, 1:00 PM MDT | Mesoscale Discussion | SPC | 90 min |
| Jul 23, 1:27 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 24, 3:44 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 25, 10:41 AM MDT | Flash Flood Watch | BOU | 11 hr |
| Jul 25, 12:48 PM MDT | Mesoscale Discussion | SPC | 57 min |
| Jul 25, 1:22 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 25, 5:08 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 25, 6:33 PM MDT | Severe Thunderstorm Warning | BOU | 42 min |
| Jul 25, 6:38 PM MDT | Severe Thunderstorm Warning | BOU | 52 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 29, 12:46 PM MDT | Mesoscale Discussion | SPC | 59 min |
| Jul 29, 5:23 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Aug 3, 8:39 PM MDT | Severe Thunderstorm Warning | BOU | 51 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, 12:59 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 14, 5:31 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Aug 17, 2:56 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 18, 10:10 PM MDT | Severe Thunderstorm Warning | BOU | 15 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 |
| Sep 5, 2:31 AM MDT | Areal Flood Advisory | BOU | 89 min |
| Sep 5, 3:14 PM MDT | Areal Flood Advisory | BOU | 61 min |
| Sep 6, 3:42 PM MDT | Special Weather Statement | BOU | 33 min |
| Sep 7, 4:04 AM MDT | Dense Fog Advisory | BOU | 5 hr |
| Sep 11, 11:58 AM MDT | Special Weather Statement | BOU | 32 min |
| Sep 11, 2:05 PM MDT | Special Weather Statement | BOU | 40 min |
| 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 9, 3:24 PM MDT | Winter Weather Advisory | 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 2, 10:06 PM MDT | Special Weather Statement | BOU | 24 min |
| Nov 2, 10:35 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Nov 10, 4:18 AM MST | Winter Weather Advisory | BOU | 44 hr |
| Nov 16, 10:36 AM MST | Winter Weather Advisory | BOU | 34 hr |
| Nov 24, 5:39 AM MST | High Wind Warning | BOU | 19 hr |
| Dec 1, 2:47 AM MST | Dense Fog Advisory | BOU | 4 hr |
| Dec 30, 1:56 PM MST | Winter Weather Advisory | BOU | 27 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 | 10 |
| Severe Thunderstorm Watch | 5 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 28 |
| Special Weather Statement | 12 |
| Flooding | |
| Flash Flood Watch | 3 |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 8 |
| Cold | |
| Freeze Warning | 3 |
| Freeze Watch | 1 |
| Wind and dust | |
| High Wind Warning | 3 |
| High Wind Watch | 2 |
| Fire | |
| Red Flag Warning | 7 |
| Fire Weather Watch | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 6 |
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.