Alert archive / Colorado / Broomfield County
Weather alerts in Broomfield County, Colorado, 2009
106 weather alerts in 2009, 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 2009. Tap one for its archive.
- Alerts
- 106
- Warnings
- 35
- Watches
- 19
- Advisories
- 15
- Busiest month
- June29 alerts
- Busiest day
- June 14, 20096 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 4 tornado warnings covering Broomfield County in 2009 had a tornado report inside them.
Broomfield County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 9 | 5 | 44% | 0 | ||
| Flash flood warnings | 0 | 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 5, 3:55 PM MST | High Wind Watch | BOU | 24 hr |
| Jan 6, 3:49 PM MST | High Wind Warning | BOU | 32 hr |
| Jan 12, 12:58 AM MST | Winter Weather Advisory | BOU | 15 hr |
| Jan 12, 8:49 AM MST | Winter Weather Advisory | BOU | 2 hr |
| Jan 22, 5:44 AM MST | Red Flag Warning | BOU | 12 hr |
| Jan 27, 3:14 PM MST | Winter Weather Advisory | BOU | 12 hr |
| Feb 5, 2:08 PM MST | Red Flag Warning | BOU | 29 hr |
| Feb 9, 9:02 AM MST | High Wind Warning | BOU | 9 hr |
| Feb 17, 12:16 PM MST | Red Flag Warning | BOU | 6 hr |
| Feb 25, 5:42 AM MST | Red Flag Warning | BOU | 12 hr |
| Mar 2, 3:05 PM MST | Red Flag Warning | BOU | 26 hr |
| Mar 3, 3:01 PM MST | Fire Weather Watch | BOU | 24 hr |
| Mar 4, 3:34 AM MST | Red Flag Warning | BOU | 17 hr |
| Mar 4, 2:42 PM MST | Red Flag Warning | BOU | 27 hr |
| Mar 14, 3:13 AM MDT | Fire Weather Watch | BOU | 25 hr |
| Mar 15, 4:01 AM MDT | Red Flag Warning | BOU | 16 hr |
| Mar 21, 2:47 PM MDT | Red Flag Warning | BOU | 30 hr |
| Mar 24, 3:59 PM MDT | Winter Storm Watch | BOU | 20 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 26, 10:35 AM MDT | Mesoscale Discussion | SPC | 5 hr |
| Mar 26, 4:46 PM MDT | Winter Weather Advisory | BOU | 13 hr |
| Mar 31, 4:27 AM MDT | Winter Weather Advisory | BOU | 44 hr |
| Apr 2, 4:20 AM MDT | Winter Storm Watch | BOU | 32 hr |
| Apr 3, 4:22 AM MDT | Winter Storm Warning | BOU | 32 hr |
| Apr 15, 4:18 AM MDT | Winter Storm Watch | BOU | 31 hr |
| Apr 16, 4:41 AM MDT | Winter Storm Warning | BOU | 61 hr |
| Apr 17, 1:17 AM MDT | Mesoscale Discussion | SPC | 4 hr |
| May 1, 10:46 PM MDT | Special Weather Statement | BOU | 29 min |
| May 22, 6:44 PM MDT | Areal Flood Advisory | BOU | 72 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 7, 10:44 AM MDT | Mesoscale Discussion | SPC | 61 min |
| Jun 7, 11:02 AM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 7, 1:16 PM MDT | Tornado Warning | BOU | 19 min |
| Jun 7, 2:30 PM MDT | Mesoscale Discussion | SPC | 60 min |
| Jun 8, 2:03 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jun 9, 4:43 PM MDT | Tornado Warning | BOU | 32 min |
| Jun 11, 11:34 AM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 11, 10:13 PM MDT | Special Weather Statement | BOU | 47 min |
| Jun 13, 12:41 PM MDT | Mesoscale Discussion | SPC | 64 min |
| Jun 13, 1:56 PM MDT | Tornado Watch | SPC | 9 hr |
| Jun 13, 3:06 PM MDT | Severe Thunderstorm Warning | BOU | 29 min |
| Jun 13, 6:42 PM MDT | Mesoscale Discussion | SPC | 63 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, 2:42 PM MDT | Tornado Warning | BOU | 48 min |
| Jun 14, 2:44 PM MDT | Areal Flood Advisory | BOU | 91 min |
| Jun 14, 2:58 PM MDT | Tornado Warning | BOU | 47 min |
| Jun 15, 2:15 PM MDT | Mesoscale Discussion | SPC | 30 min |
| Jun 17, 2:30 PM MDT | Tornado Watch | SPC | 8 hr |
| Jun 17, 4:43 PM MDT | Mesoscale Discussion | SPC | 92 min |
| Jun 23, 2:51 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 24, 5:15 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Jun 25, 1:06 PM MDT | Mesoscale Discussion | SPC | 54 min |
| Jun 25, 4:22 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Jun 25, 5:50 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Jun 26, 2:46 PM MDT | Severe Thunderstorm Warning | BOU | 28 min |
| Jun 26, 2:58 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| Jul 3, 3:19 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Jul 3, 4:27 PM MDT | Special Weather Statement | BOU | 63 min |
| Jul 3, 4:43 PM MDT | Special Weather Statement | BOU | 32 min |
| Jul 4, 1:52 PM MDT | Mesoscale Discussion | SPC | 113 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 10, 8:38 PM MDT | Special Weather Statement | BOU | 37 min |
| Jul 10, 9:01 PM MDT | Areal Flood Advisory | BOU | 89 min |
| Jul 11, 3:35 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Jul 12, 2:05 PM MDT | Mesoscale Discussion | SPC | 85 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 20, 9:47 PM MDT | Special Weather Statement | BOU | 28 min |
| Jul 20, 9:56 PM MDT | Severe Thunderstorm Warning | BOU | 34 min |
| Jul 20, 10:06 PM MDT | Severe Thunderstorm Warning | BOU | 39 min |
| Jul 20, 10:56 PM MDT | Mesoscale Discussion | SPC | 94 min |
| Jul 21, 2:44 PM MDT | Mesoscale Discussion | SPC | 61 min |
| Jul 22, 1:16 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Aug 3, 3:20 PM MDT | Severe Thunderstorm Warning | BOU | 31 min |
| Aug 5, 8:42 PM MDT | Special Weather Statement | BOU | 48 min |
| Aug 5, 9:19 PM MDT | Severe Thunderstorm Warning | BOU | 26 min |
| Aug 10, 1:07 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Aug 10, 4:43 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 15, 1:07 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Aug 18, 11:41 AM MDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 29, 3:27 PM MDT | Fire Weather Watch | BOU | 14 hr |
| Sep 30, 5:00 AM MDT | Red Flag Warning | BOU | 15 hr |
| Sep 30, 2:21 PM MDT | Freeze Watch | BOU | 13 hr |
| Sep 30, 2:21 PM MDT | High Wind Warning | BOU | 13 hr |
| Oct 1, 3:05 AM MDT | Freeze Warning | BOU | 29 hr |
| Oct 2, 3:38 PM MDT | Freeze Warning | BOU | 16 hr |
| Oct 14, 4:12 AM MDT | Dense Fog Advisory | BOU | 5 hr |
| Oct 14, 9:07 AM MDT | Dense Fog Advisory | BOU | 113 min |
| Oct 18, 4:35 AM MDT | Red Flag Warning | BOU | 13 hr |
| Oct 26, 3:15 PM MDT | Winter Storm Watch | BOU | 12 hr |
| Oct 27, 3:26 AM MDT | Winter Storm Warning | BOU | 69 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 5, 10:22 AM MST | Winter Weather Advisory | BOU | 24 hr |
| Dec 7, 5:21 AM MST | Winter Weather Advisory | BOU | 47 hr |
| Dec 9, 4:31 AM MST | Wind Chill Advisory | BOU | 4 hr |
| Dec 10, 2:41 AM MST | Winter Weather Advisory | BOU | 8 hr |
| Dec 21, 7:53 PM MST | Winter Weather Advisory | BOU | 61 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 | 9 |
| Tornado Warning | 4 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 3 |
| Mesoscale Discussion | 30 |
| Special Weather Statement | 7 |
| Flooding | |
| Areal Flood Advisory | 3 |
| Winter | |
| Blizzard Warning | 1 |
| Winter Storm Warning | 5 |
| Winter Storm Watch | 5 |
| Winter Weather Advisory | 9 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 1 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 3 |
| High Wind Watch | 1 |
| Fire | |
| Red Flag Warning | 11 |
| 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 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.