Alert archive / Colorado / Broomfield County
Weather alerts in Broomfield County, Colorado, 2019
118 weather alerts in 2019, 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 2019. Tap one for its archive.
- Alerts
- 118
- Warnings
- 19
- Watches
- 19
- Advisories
- 30
- Busiest month
- July28 alerts
- Busiest day
- July 6, 20197 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, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 6 | 4 | 33% | 4 | 50% | 9 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 32 | 11 | 66% | 33 | 48% | 11 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 281 | 117 | 58% | 382 | 77% | 18 min |
| NWS Denver/Boulder, CO: flash flood warnings | 15 | 2 | 87% | 3 | 67% | 58 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 6, 4:15 AM MST | High Wind Watch | BOU | 8 hr |
| Jan 6, 12:31 PM MST | High Wind Warning | BOU | 33 hr |
| Jan 6, 8:09 PM MST | High Wind Watch | BOU | 7 hr |
| Jan 10, 2:42 PM MST | Winter Weather Advisory | BOU | 33 hr |
| Jan 20, 3:01 PM MST | Winter Weather Advisory | BOU | 42 hr |
| Feb 5, 4:11 AM MST | Winter Weather Advisory | BOU | 48 hr |
| Feb 20, 3:59 PM MST | Winter Weather Advisory | BOU | 66 hr |
| Feb 25, 11:00 PM MST | Dense Fog Advisory | BOU | 9 hr |
| Feb 27, 3:10 AM MST | Dense Fog Advisory | BOU | 6 hr |
| Feb 28, 5:33 PM MST | Winter Storm Watch | BOU | 17 hr |
| Feb 28, 5:33 PM MST | Winter Weather Advisory | BOU | 58 hr |
| Mar 3, 3:36 AM MST | Wind Chill Advisory | BOU | 5 hr |
| Mar 3, 3:36 AM MST | Wind Chill Advisory | BOU | 29 hr |
| Mar 11, 6:48 AM MDT | Winter Storm Watch | BOU | 28 hr |
| Mar 11, 3:24 PM MDT | Blizzard Warning | BOU | 68 hr |
| Mar 12, 10:55 AM MDT | Winter Storm Warning | BOU | 34 hr |
| Mar 13, 10:27 AM MDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 13, 1:37 PM MDT | Mesoscale Discussion | SPC | 4 hr |
| Apr 8, 3:10 PM MDT | Winter Storm Watch | BOU | 21 hr |
| Apr 9, 11:47 AM MDT | Blizzard Warning | BOU | 47 hr |
| Apr 9, 11:47 AM MDT | Winter Storm Warning | BOU | 47 hr |
| Apr 10, 8:31 PM MDT | Winter Weather Advisory | BOU | 22 hr |
| Apr 26, 6:54 PM MDT | Special Weather Statement | BOU | 51 min |
| May 6, 12:50 PM MDT | Mesoscale Discussion | SPC | 115 min |
| May 6, 6:37 PM MDT | Special Weather Statement | BOU | 38 min |
| May 6, 6:45 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| May 6, 6:47 PM MDT | Severe Thunderstorm Warning | BOU | 22 min |
| May 7, 1:01 AM MDT | Dense Fog Advisory | BOU | 7 hr |
| May 7, 12:29 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 7, 8:53 PM MDT | Dense Fog Advisory | BOU | 12 hr |
| May 8, 3:50 PM MDT | Freeze Watch | BOU | 24 hr |
| May 9, 4:03 PM MDT | Frost Advisory | BOU | 16 hr |
| May 10, 2:51 PM MDT | Frost Advisory | BOU | 18 hr |
| May 18, 2:49 PM MDT | Frost Advisory | BOU | 17 hr |
| May 20, 4:50 AM MDT | Winter Weather Advisory | BOU | 31 hr |
| May 21, 12:01 PM MDT | Freeze Warning | BOU | 19 hr |
| May 26, 2:07 PM MDT | Mesoscale Discussion | SPC | 113 min |
| May 28, 3:44 AM MDT | Special Weather Statement | BOU | 46 min |
| May 28, 2:27 PM MDT | Special Weather Statement | BOU | 33 min |
| Jun 2, 10:57 AM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 2, 12:11 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 2, 2:26 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 7, 12:37 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 8, 3:39 PM MDT | Severe Thunderstorm Warning | BOU | 40 min |
| Jun 8, 3:44 PM MDT | Mesoscale Discussion | SPC | 61 min |
| Jun 8, 4:35 PM MDT | Severe Thunderstorm Warning | BOU | 25 min |
| Jun 14, 12:44 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 16, 8:40 PM MDT | Special Weather Statement | BOU | 50 min |
| Jun 17, 12:04 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 18, 4:39 PM MDT | Special Weather Statement | BOU | 21 min |
| Jun 20, 2:51 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 21, 11:56 AM MDT | Mesoscale Discussion | SPC | 94 min |
| Jun 23, 11:36 AM MDT | Special Weather Statement | BOU | 24 min |
| Jul 1, 2:46 PM MDT | Special Weather Statement | BOU | 29 min |
| Jul 4, 2:10 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 4, 3:01 PM MDT | Tornado Watch | SPC | 7 hr |
| Jul 4, 5:40 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jul 4, 6:56 PM MDT | Severe Thunderstorm Warning | BOU | 17 min |
| Jul 5, 1:18 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Jul 5, 3:36 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 5, 6:01 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jul 5, 7:01 PM MDT | Severe Thunderstorm Warning | BOU | 44 min |
| Jul 5, 7:38 PM MDT | Areal Flood Advisory | BOU | 2 hr |
| Jul 5, 9:18 PM MDT | Mesoscale Discussion | SPC | 57 min |
| Jul 6, 12:25 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jul 6, 12:42 PM MDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 6, 4:55 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jul 7, 2:14 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 7, 6:17 PM MDT | Special Weather Statement | BOU | 43 min |
| Jul 8, 7:17 PM MDT | Special Weather Statement | BOU | 28 min |
| Jul 13, 6:43 PM MDT | Special Weather Statement | BOU | 47 min |
| Jul 13, 7:14 PM MDT | Special Weather Statement | BOU | 46 min |
| Jul 15, 2:38 PM MDT | Special Weather Statement | BOU | 37 min |
| Jul 20, 12:53 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 20, 2:29 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 20, 5:43 PM MDT | Mesoscale Discussion | SPC | 92 min |
| Jul 21, 4:37 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Jul 21, 10:34 PM MDT | Areal Flood Advisory | BOU | 116 min |
| Jul 21, 10:59 PM MDT | Special Weather Statement | BOU | 46 min |
| Jul 22, 2:05 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 22, 5:38 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Aug 11, 4:51 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Aug 16, 1:40 PM MDT | Mesoscale Discussion | SPC | 65 min |
| Aug 21, 12:51 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Aug 21, 2:47 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 21, 4:39 PM MDT | Mesoscale Discussion | SPC | 96 min |
| Aug 21, 6:22 PM MDT | Areal Flood Advisory | BOU | 113 min |
| Aug 22, 2:11 PM MDT | Mesoscale Discussion | SPC | 94 min |
| Aug 30, 2:13 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 8, 2:40 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Sep 8, 2:56 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 8, 5:34 PM MDT | Special Weather Statement | BOU | 41 min |
| Sep 20, 10:02 AM MDT | Red Flag Warning | BOU | 10 hr |
| Sep 27, 3:02 PM MDT | Fire Weather Watch | BOU | 13 hr |
| Sep 28, 4:15 AM MDT | Red Flag Warning | BOU | 39 hr |
| Sep 29, 7:46 AM MDT | Special Weather Statement | BOU | 59 min |
| Oct 6, 3:37 AM MDT | Frost Advisory | BOU | 28 hr |
| Oct 8, 3:06 PM MDT | Freeze Watch | BOU | 13 hr |
| Oct 9, 4:18 AM MDT | Freeze Warning | BOU | 29 hr |
| Oct 9, 3:17 PM MDT | Winter Weather Advisory | BOU | 23 hr |
| Oct 18, 2:31 PM MDT | Fire Weather Watch | BOU | 23 hr |
| Oct 20, 2:49 AM MDT | High Wind Warning | BOU | 16 hr |
| Oct 23, 3:54 AM MDT | Winter Weather Advisory | BOU | 27 hr |
| Oct 25, 1:52 PM MDT | Winter Storm Watch | BOU | 24 hr |
| Oct 26, 1:54 PM MDT | Winter Weather Advisory | BOU | 46 hr |
| Oct 28, 2:26 PM MDT | Winter Storm Warning | BOU | 37 hr |
| Nov 6, 2:54 PM MST | Winter Weather Advisory | BOU | 12 hr |
| Nov 10, 2:55 PM MST | Winter Weather Advisory | BOU | 18 hr |
| Nov 21, 4:11 AM MST | Winter Weather Advisory | BOU | 5 hr |
| Nov 24, 4:38 AM MST | Winter Storm Watch | BOU | 9 hr |
| Nov 24, 1:40 PM MST | Winter Storm Warning | BOU | 51 hr |
| Nov 25, 7:42 PM MST | Mesoscale Discussion | SPC | 6 hr |
| Nov 28, 3:00 AM MST | High Wind Watch | BOU | 24 hr |
| Nov 29, 1:44 AM MST | Dense Fog Advisory | BOU | 9 hr |
| Nov 29, 3:02 AM MST | High Wind Warning | BOU | 39 hr |
| Nov 29, 5:39 PM MST | Dense Fog Advisory | BOU | 6 hr |
| Dec 26, 7:16 AM MST | Dense Fog Advisory | BOU | 3 hr |
| Dec 27, 1:57 PM MST | Winter Weather Advisory | BOU | 34 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 | 6 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 34 |
| Special Weather Statement | 16 |
| Flooding | |
| Areal Flood Advisory | 3 |
| Winter | |
| Blizzard Warning | 2 |
| Winter Storm Warning | 4 |
| Winter Storm Watch | 5 |
| Winter Weather Advisory | 14 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 2 |
| Frost Advisory | 4 |
| Wind Chill Advisory | 2 |
| Wind and dust | |
| High Wind Warning | 3 |
| High Wind Watch | 3 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 7 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20182020
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.