Alert archive / Colorado / Denver County
Weather alerts in Denver County, Colorado, 2015
115 weather alerts in 2015, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Denver County and its neighbors
Each county as a circle sized by its count in 2015. Tap one for its archive.
- Alerts
- 115
- Warnings
- 28
- Watches
- 12
- Advisories
- 26
- Busiest month
- June52 alerts
- Busiest day
- June 5, 201513 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 3 tornado warnings covering Denver County in 2015 had a tornado report inside them.
Denver County, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 3 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 14 | 7 | 50% | 11 | 82% | 14 min |
| Flash flood warnings | 3 | 1 | 67% | 3 | 100% | 13 min |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 59 | 12 | 80% | 29 | 52% | 13 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 193 | 70 | 64% | 208 | 67% | 15 min |
| NWS Denver/Boulder, CO: flash flood warnings | 33 | 5 | 85% | 9 | 100% | 37 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, 6:16 PM MST | Winter Weather Advisory | BOU | 5 hr |
| Jan 7, 3:25 AM MST | Winter Weather Advisory | BOU | 6 hr |
| Jan 8, 3:08 PM MST | Winter Weather Advisory | BOU | 17 hr |
| Jan 31, 10:49 PM MST | Winter Weather Advisory | BOU | 8 hr |
| Feb 15, 3:56 AM MST | Winter Weather Advisory | BOU | 40 hr |
| Feb 19, 2:26 PM MST | Winter Storm Watch | BOU | 22 hr |
| Feb 20, 4:25 AM MST | Winter Storm Warning | BOU | 67 hr |
| Feb 21, 12:38 PM MST | Mesoscale Discussion | SPC | 5 hr |
| Feb 25, 4:18 AM MST | Winter Weather Advisory | BOU | 24 hr |
| Mar 3, 4:27 AM MST | Winter Weather Advisory | BOU | 25 hr |
| Mar 23, 2:40 PM MDT | Red Flag Warning | BOU | 27 hr |
| Mar 23, 11:28 PM MDT | Special Weather Statement | BOU | 32 min |
| May 1, 12:31 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 4, 7:09 PM MDT | Areal Flood Advisory | BOU | 111 min |
| May 8, 11:08 AM MDT | Areal Flood Advisory | BOU | 60 hr |
| May 9, 5:10 AM MDT | Flash Flood Watch | BOU | 15 hr |
| May 9, 5:15 AM MDT | Winter Storm Warning | BOU | 25 hr |
| May 9, 8:50 AM MDT | Areal Flood Warning | BOU | 12 hr |
| May 9, 9:09 AM MDT | Winter Storm Watch | BOU | 4 hr |
| May 10, 5:26 AM MDT | Frost Advisory | BOU | 26 hr |
| May 10, 5:56 AM MDT | Winter Storm Warning | BOU | 3 hr |
| May 14, 8:36 PM MDT | Special Weather Statement | BOU | 24 min |
| May 23, 12:54 PM MDT | Tornado Watch | SPC | 6 hr |
| May 23, 1:38 PM MDT | Areal Flood Advisory | BOU | 2 hr |
| May 25, 6:31 PM MDT | Special Weather Statement | BOU | 29 min |
| May 25, 6:58 PM MDT | Special Weather Statement | BOU | 32 min |
| May 27, 6:29 PM MDT | Special Weather Statement | BOU | 46 min |
| Jun 1, 1:45 PM MDT | Special Weather Statement | BOU | 30 min |
| Jun 3, 12:34 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 3, 2:03 PM MDT | Tornado Watch | SPC | 7 hr |
| Jun 3, 4:59 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Jun 3, 5:29 PM MDT | Severe Thunderstorm Warning | BOU | 46 min |
| Jun 3, 7:14 PM MDT | Mesoscale Discussion | SPC | 61 min |
| Jun 3, 7:16 PM MDT | Special Weather Statement | BOU | 44 min |
| Jun 4, 2:20 PM MDT | Tornado Watch | SPC | 8 hr |
| Jun 4, 4:28 PM MDT | Severe Thunderstorm Warning | BOU | 24 min |
| Jun 4, 5:22 PM MDT | Mesoscale Discussion | SPC | 113 min |
| Jun 4, 8:20 PM MDT | Mesoscale Discussion | SPC | 115 min |
| Jun 4, 9:19 PM MDT | Severe Thunderstorm Warning | BOU | 26 min |
| Jun 4, 9:42 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jun 4, 9:47 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jun 4, 10:39 PM MDT | Severe Thunderstorm Warning | BOU | 22 min |
| Jun 4, 11:00 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Jun 4, 11:16 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jun 5, 12:42 AM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jun 5, 12:48 AM MDT | Areal Flood Advisory | BOU | 117 min |
| Jun 5, 1:45 AM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| Jun 5, 4:27 AM MDT | Flash Flood Watch | BOU | 18 hr |
| Jun 5, 12:49 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 5, 1:09 PM MDT | Tornado Watch | SPC | 6 hr |
| Jun 5, 8:50 PM MDT | Special Weather Statement | BOU | 25 min |
| Jun 5, 9:11 PM MDT | Areal Flood Advisory | BOU | 94 min |
| Jun 5, 9:20 PM MDT | Special Weather Statement | BOU | 25 min |
| Jun 6, 2:14 PM MDT | Mesoscale Discussion | SPC | 91 min |
| Jun 6, 2:20 PM MDT | Special Weather Statement | BOU | 40 min |
| Jun 6, 9:33 PM MDT | Mesoscale Discussion | SPC | 57 min |
| Jun 7, 1:36 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 7, 5:55 PM MDT | Areal Flood Advisory | BOU | 95 min |
| Jun 10, 11:41 AM MDT | Flash Flood Watch | BOU | 39 hr |
| Jun 11, 6:43 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jun 11, 8:51 PM MDT | River Flood Warning | BOU | 8 hr |
| Jun 13, 6:35 PM MDT | Severe Thunderstorm Warning | BOU | 25 min |
| Jun 13, 7:01 PM MDT | Flash Flood Warning | BOU | 2 hr |
| Jun 16, 4:53 PM MDT | Mesoscale Discussion | SPC | 97 min |
| Jun 23, 4:09 PM MDT | Mesoscale Discussion | SPC | 96 min |
| Jun 23, 7:15 PM MDT | Special Weather Statement | BOU | 30 min |
| Jun 23, 7:52 PM MDT | Special Weather Statement | BOU | 23 min |
| Jun 24, 2:34 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 24, 4:45 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| Jun 24, 5:00 PM MDT | Tornado Warning | BOU | 19 min |
| Jun 24, 5:08 PM MDT | Areal Flood Advisory | BOU | 52 min |
| Jun 24, 5:09 PM MDT | Tornado Warning | BOU | 21 min |
| Jun 24, 5:22 PM MDT | Flash Flood Warning | BOU | 113 min |
| Jun 24, 7:19 PM MDT | Flash Flood Warning | BOU | 3 hr |
| Jun 25, 2:30 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 25, 4:25 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jun 25, 6:34 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Jun 25, 6:39 PM MDT | Areal Flood Advisory | BOU | 111 min |
| Jun 25, 9:30 PM MDT | Mesoscale Discussion | SPC | 30 min |
| Jul 1, 2:43 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 15, 4:17 PM MDT | Special Weather Statement | BOU | 43 min |
| Jul 15, 4:56 PM MDT | Special Weather Statement | BOU | 49 min |
| Jul 17, 4:00 PM MDT | Special Weather Statement | BOU | 45 min |
| Jul 17, 4:21 PM MDT | Special Weather Statement | BOU | 39 min |
| Jul 18, 2:41 PM MDT | Special Weather Statement | BOU | 49 min |
| Jul 18, 3:33 PM MDT | Special Weather Statement | BOU | 42 min |
| Jul 18, 5:06 PM MDT | Special Weather Statement | BOU | 39 min |
| Jul 21, 12:46 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Aug 2, 3:08 PM MDT | Special Weather Statement | BOU | 37 min |
| Aug 7, 2:12 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 11, 3:39 PM MDT | Special Weather Statement | BOU | 51 min |
| Aug 11, 4:04 PM MDT | Tornado Warning | BOU | 26 min |
| Aug 11, 4:40 PM MDT | Areal Flood Advisory | BOU | 95 min |
| Aug 16, 12:08 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 16, 2:53 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 17, 1:59 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 17, 2:32 PM MDT | Tornado Watch | SPC | 7 hr |
| Aug 31, 4:16 PM MDT | Special Weather Statement | BOU | 29 min |
| Sep 1, 5:22 PM MDT | Special Weather Statement | BOU | 38 min |
| Sep 7, 4:46 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Sep 29, 1:48 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Sep 29, 4:43 PM MDT | Severe Thunderstorm Warning | BOU | 32 min |
| Sep 29, 4:55 PM MDT | Severe Thunderstorm Warning | BOU | 35 min |
| Oct 2, 2:09 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 23, 3:54 AM MDT | Frost Advisory | BOU | 28 hr |
| Oct 27, 3:13 AM MDT | Frost Advisory | BOU | 29 hr |
| Nov 10, 5:05 AM MST | Winter Weather Advisory | BOU | 30 hr |
| Nov 11, 1:27 AM MST | Mesoscale Discussion | SPC | 6 hr |
| Nov 15, 3:36 PM MST | Blizzard Watch | BOU | 14 hr |
| Nov 16, 5:57 AM MST | Blizzard Warning | BOU | 32 hr |
| Nov 25, 10:25 AM MST | Winter Weather Advisory | BOU | 42 hr |
| Dec 14, 3:45 AM MST | Winter Weather Advisory | BOU | 37 hr |
| Dec 14, 3:12 PM MST | Winter Storm Warning | BOU | 26 hr |
| Dec 15, 2:55 AM MST | Mesoscale Discussion | SPC | 4 hr |
| Dec 23, 3:14 AM MST | Dense Fog Advisory | BOU | 7 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20142016
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.