Alert archive / Colorado / Arapahoe County
Weather alerts in Arapahoe County, Colorado, 2024
195 weather alerts in 2024, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Arapahoe County and its neighbors
Each county as a circle sized by its count in 2024. Tap one for its archive.
- Alerts
- 195
- Warnings
- 85
- Watches
- 31
- Advisories
- 33
- Busiest month
- June37 alerts
- Busiest day
- May 31, 202412 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 1 tornado reports fell inside a warning.
Arapahoe County, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 1 | 0% | |||
| Severe thunderstorm warnings | 43 | 18 | 58% | 26 | 85% | 20 min |
| Flash flood warnings | 5 | 2 | 60% | 0 |
Each office's whole area, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 27 | 2 | 93% | 15 | 20% | 11 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 295 | 119 | 60% | 339 | 79% | 20 min |
| NWS Denver/Boulder, CO: flash flood warnings | 32 | 9 | 72% | 14 | 79% | 40 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 7, 3:35 AM MST | Winter Storm Watch | BOU | 11 hr |
| Jan 7, 3:35 AM MST | Winter Weather Advisory | BOU | 31 hr |
| Jan 7, 2:05 PM MST | Winter Storm Warning | BOU | 24 hr |
| Jan 11, 3:10 AM MST | Wind Chill Watch | BOU | 23 hr |
| Jan 12, 2:10 AM MST | Wind Chill Warning | BOU | 4 days |
| Feb 1, 2:09 PM MST | Winter Storm Warning | BOU | 54 hr |
| Feb 1, 2:09 PM MST | Winter Weather Advisory | BOU | 54 hr |
| Feb 2, 2:20 AM MST | Winter Storm Watch | BOU | 12 hr |
| Feb 2, 2:23 PM MST | Winter Storm Watch | BOU | 18 hr |
| Feb 3, 5:53 PM MST | Dense Fog Advisory | BOU | 16 hr |
| Feb 4, 5:15 PM MST | Dense Fog Advisory | BOU | 18 hr |
| Feb 8, 2:30 PM MST | Winter Storm Watch | BOU | 22 hr |
| Feb 9, 12:47 PM MST | Winter Weather Advisory | BOU | 40 hr |
| Feb 9, 10:19 PM MST | Winter Storm Warning | BOU | 25 hr |
| Feb 14, 2:18 PM MST | Winter Weather Advisory | BOU | 63 hr |
| Feb 15, 2:22 AM MST | Dense Fog Advisory | BOU | 8 hr |
| Feb 24, 1:49 AM MST | Fire Weather Watch | BOU | 12 hr |
| Feb 24, 1:43 PM MST | Red Flag Warning | BOU | 34 hr |
| Feb 25, 2:13 AM MST | Fire Weather Watch | BOU | 11 hr |
| Feb 25, 1:32 PM MST | Red Flag Warning | BOU | 28 hr |
| Feb 27, 8:39 AM MST | Snow Squall Warning | BOU | 36 min |
| Feb 27, 9:09 AM MST | Snow Squall Warning | BOU | 51 min |
| Feb 27, 9:12 AM MST | Mesoscale Discussion | SPC | 3 hr |
| Feb 27, 9:39 AM MST | Snow Squall Warning | BOU | 51 min |
| Feb 27, 10:30 AM MST | Snow Squall Warning | BOU | 30 min |
| Feb 29, 12:10 PM MST | Fire Weather Watch | BOU | 19 hr |
| Mar 1, 6:46 AM MST | Red Flag Warning | BOU | 36 hr |
| Mar 11, 2:29 PM MDT | Winter Storm Watch | BOU | 47 hr |
| Mar 12, 4:17 AM MDT | Winter Weather Advisory | BOU | 3 days |
| Mar 12, 2:12 PM MDT | Winter Storm Warning | BOU | 64 hr |
| Mar 23, 3:22 AM MDT | Winter Weather Advisory | BOU | 57 hr |
| Mar 23, 3:06 PM MDT | Winter Storm Watch | BOU | 13 hr |
| Mar 24, 3:53 AM MDT | Blizzard Warning | BOU | 26 hr |
| Mar 30, 2:14 PM MDT | Red Flag Warning | BOU | 30 hr |
| Apr 2, 2:33 PM MDT | Fire Weather Watch | BOU | 47 hr |
| Apr 4, 4:25 AM MDT | Red Flag Warning | BOU | 41 hr |
| Apr 4, 2:58 PM MDT | High Wind Watch | BOU | 36 hr |
| Apr 5, 11:50 AM MDT | High Wind Warning | BOU | 54 hr |
| Apr 5, 1:37 PM MDT | Red Flag Warning | BOU | 53 hr |
| Apr 14, 1:05 AM MDT | Red Flag Warning | BOU | 19 hr |
| Apr 14, 3:30 AM MDT | Fire Weather Watch | BOU | 11 hr |
| Apr 14, 2:13 PM MDT | Red Flag Warning | BOU | 30 hr |
| Apr 19, 3:22 AM MDT | Winter Weather Advisory | BOU | 30 hr |
| Apr 20, 2:00 PM MDT | Dense Fog Advisory | BOU | 19 hr |
| Apr 26, 8:38 PM MDT | Winter Weather Advisory | BOU | 27 hr |
| May 5, 1:59 PM MDT | High Wind Warning | BOU | 37 hr |
| May 6, 1:24 PM MDT | Freeze Watch | BOU | 23 hr |
| May 7, 3:07 AM MDT | Freeze Warning | BOU | 29 hr |
| May 7, 4:07 PM MDT | Frost Advisory | BOU | 16 hr |
| May 21, 7:03 PM MDT | Frost Advisory | BOU | 13 hr |
| May 22, 6:39 AM MDT | Areal Flood Advisory | BOU | 9 hr |
| May 28, 7:51 PM MDT | Severe Thunderstorm Warning | BOU | 24 min |
| May 28, 8:15 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| May 29, 12:18 PM MDT | Mesoscale Discussion | SPC | 117 min |
| May 29, 1:51 PM MDT | Special Weather Statement | BOU | 39 min |
| May 29, 2:27 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 30, 9:43 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| May 30, 10:12 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| May 30, 10:35 PM MDT | Severe Thunderstorm Warning | BOU | 40 min |
| May 30, 10:47 PM MDT | Severe Thunderstorm Warning | BOU | 58 min |
| May 30, 10:57 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| May 30, 11:11 PM MDT | Severe Thunderstorm Warning | BOU | 38 min |
| May 31, 2:00 PM MDT | Mesoscale Discussion | SPC | 90 min |
| May 31, 4:07 PM MDT | Special Weather Statement | BOU | 23 min |
| May 31, 4:27 PM MDT | Special Weather Statement | BOU | 33 min |
| May 31, 4:33 PM MDT | Severe Thunderstorm Warning | BOU | 27 min |
| May 31, 5:00 PM MDT | Severe Thunderstorm Warning | BOU | 30 min |
| May 31, 5:44 PM MDT | Mesoscale Discussion | SPC | 91 min |
| Jun 1, 1:08 PM MDT | Mesoscale Discussion | SPC | 97 min |
| Jun 7, 2:23 PM MDT | Severe Thunderstorm Warning | BOU | 40 min |
| Jun 7, 7:54 PM MDT | Severe Thunderstorm Warning | BOU | 36 min |
| Jun 8, 11:51 AM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 8, 12:26 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 8, 1:34 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Jun 8, 2:06 PM MDT | Severe Thunderstorm Warning | BOU | 39 min |
| Jun 8, 2:10 PM MDT | Severe Thunderstorm Warning | BOU | 35 min |
| Jun 8, 2:44 PM MDT | Severe Thunderstorm Warning | BOU | 31 min |
| Jun 8, 3:58 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| Jun 8, 4:26 PM MDT | Severe Thunderstorm Warning | BOU | 49 min |
| Jun 8, 4:42 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jun 8, 5:09 PM MDT | Areal Flood Advisory | BOU | 2 hr |
| Jun 8, 5:11 PM MDT | Severe Thunderstorm Warning | BOU | 49 min |
| Jun 9, 3:08 PM MDT | Severe Thunderstorm Warning | BOU | 37 min |
| Jun 9, 3:32 PM MDT | Flash Flood Warning | BOU | 113 min |
| Jun 9, 3:42 PM MDT | Severe Thunderstorm Warning | BOU | 33 min |
| Jun 9, 4:34 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Jun 9, 4:48 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jun 9, 5:50 PM MDT | Flash Flood Warning | BOU | 3 hr |
| Jun 9, 8:51 PM MDT | Areal Flood Warning | BOU | 6 hr |
| Jun 10, 2:45 AM MDT | Areal Flood Warning | BOU | 5 hr |
| Jun 13, 12:53 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 14, 1:44 PM MDT | Mesoscale Discussion | SPC | 61 min |
| Jun 14, 1:52 PM MDT | Severe Thunderstorm Warning | BOU | 38 min |
| Jun 14, 2:10 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 14, 2:26 PM MDT | Severe Thunderstorm Warning | BOU | 15 min |
| Jun 15, 2:32 PM MDT | Red Flag Warning | BOU | 27 hr |
| Jun 15, 2:35 PM MDT | Heat Advisory | BOU | 28 hr |
| Jun 16, 2:42 PM MDT | Fire Weather Watch | BOU | 12 hr |
| Jun 16, 2:42 PM MDT | Red Flag Warning | BOU | 30 hr |
| Jun 20, 5:16 PM MDT | Special Weather Statement | BOU | 29 min |
| Jun 22, 2:15 PM MDT | Heat Advisory | BOU | 3 days |
| Jun 26, 2:53 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 26, 5:50 PM MDT | Special Weather Statement | BOU | 25 min |
| Jun 27, 8:04 PM MDT | Special Weather Statement | BOU | 26 min |
| Jun 30, 3:54 PM MDT | Mesoscale Discussion | SPC | 96 min |
| Jul 3, 3:24 PM MDT | Severe Thunderstorm Warning | BOU | 36 min |
| Jul 3, 3:47 PM MDT | Severe Thunderstorm Warning | BOU | 43 min |
| Jul 3, 4:27 PM MDT | Severe Thunderstorm Warning | BOU | 28 min |
| Jul 7, 2:12 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 7, 2:51 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 7, 5:01 PM MDT | Special Weather Statement | BOU | 29 min |
| Jul 10, 12:24 PM MDT | Heat Advisory | BOU | 56 hr |
| Jul 10, 12:24 PM MDT | Heat Advisory | BOU | 3 days |
| Jul 10, 12:24 PM MDT | Heat Advisory | BOU | 4 days |
| Jul 13, 10:27 PM MDT | Special Weather Statement | BOU | 48 min |
| Jul 15, 2:49 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jul 17, 12:20 PM MDT | Mesoscale Discussion | SPC | 115 min |
| Jul 17, 2:47 PM MDT | Special Weather Statement | BOU | 28 min |
| Jul 17, 2:49 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Jul 18, 4:01 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jul 18, 7:05 PM MDT | Severe Thunderstorm Warning | BOU | 40 min |
| Jul 20, 1:57 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 20, 9:14 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Jul 20, 9:20 PM MDT | Severe Thunderstorm Warning | BOU | 25 min |
| Jul 25, 9:55 AM MDT | Red Flag Warning | BOU | 9 hr |
| Jul 27, 3:16 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Jul 29, 2:41 AM MDT | Heat Advisory | BOU | 41 hr |
| Aug 2, 1:42 PM MDT | Heat Advisory | BOU | 54 hr |
| Aug 2, 2:49 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Aug 2, 3:31 PM MDT | Special Weather Statement | BOU | 44 min |
| Aug 2, 7:29 PM MDT | Severe Thunderstorm Warning | BOU | 46 min |
| Aug 2, 8:08 PM MDT | Severe Thunderstorm Warning | BOU | 52 min |
| Aug 5, 6:33 PM MDT | Special Weather Statement | BOU | 42 min |
| Aug 6, 5:35 PM MDT | Special Weather Statement | BOU | 40 min |
| Aug 6, 5:46 PM MDT | Special Weather Statement | BOU | 44 min |
| Aug 6, 5:52 PM MDT | Special Weather Statement | BOU | 38 min |
| Aug 7, 12:57 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 7, 5:09 PM MDT | Severe Thunderstorm Warning | BOU | 37 min |
| Aug 11, 6:06 PM MDT | Severe Thunderstorm Warning | BOU | 24 min |
| Aug 12, 9:50 AM MDT | Flood Watch | BOU | 14 hr |
| Aug 12, 1:05 PM MDT | Mesoscale Discussion | SPC | 115 min |
| Aug 12, 3:51 PM MDT | Special Weather Statement | BOU | 39 min |
| Aug 12, 5:09 PM MDT | Flash Flood Warning | BOU | 3 hr |
| Aug 13, 10:29 AM MDT | Flood Watch | BOU | 10 hr |
| Aug 13, 2:42 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 13, 3:35 PM MDT | Special Weather Statement | BOU | 25 min |
| Aug 13, 3:50 PM MDT | Severe Thunderstorm Warning | BOU | 40 min |
| Aug 13, 4:26 PM MDT | Severe Thunderstorm Warning | BOU | 49 min |
| Aug 13, 4:52 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 13, 5:25 PM MDT | Severe Thunderstorm Warning | BOU | 50 min |
| Aug 13, 6:02 PM MDT | Areal Flood Advisory | BOU | 28 min |
| Aug 13, 6:30 PM MDT | Flash Flood Warning | BOU | 95 min |
| Aug 19, 1:19 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Aug 19, 2:57 PM MDT | Severe Thunderstorm Warning | BOU | 48 min |
| Aug 19, 3:36 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Aug 19, 3:41 PM MDT | Severe Thunderstorm Warning | BOU | 49 min |
| Aug 19, 3:53 PM MDT | Flash Flood Warning | BOU | 3 hr |
| Aug 19, 6:07 PM MDT | Mesoscale Discussion | SPC | 53 min |
| Aug 19, 7:01 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Aug 22, 5:00 PM MDT | Severe Thunderstorm Warning | BOU | 45 min |
| Aug 22, 5:18 PM MDT | Special Weather Statement | BOU | 27 min |
| Aug 23, 3:35 PM MDT | Special Weather Statement | BOU | 40 min |
| Sep 2, 3:53 AM MDT | Red Flag Warning | BOU | 16 hr |
| Sep 4, 4:18 PM MDT | Special Weather Statement | BOU | 42 min |
| Sep 10, 2:01 PM MDT | Fire Weather Watch | BOU | 24 hr |
| Sep 11, 2:14 PM MDT | Red Flag Warning | BOU | 30 hr |
| Sep 17, 1:08 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 17, 2:36 PM MDT | Severe Thunderstorm Warning | BOU | 39 min |
| Sep 17, 2:54 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 17, 3:05 PM MDT | Special Weather Statement | BOU | 40 min |
| Sep 17, 4:04 PM MDT | Severe Thunderstorm Warning | BOU | 41 min |
| Sep 17, 4:29 PM MDT | Severe Thunderstorm Warning | BOU | 28 min |
| Sep 29, 1:13 PM MDT | Fire Weather Watch | BOU | 39 hr |
| Oct 3, 2:18 PM MDT | Fire Weather Watch | BOU | 23 hr |
| Oct 4, 1:27 PM MDT | Red Flag Warning | BOU | 30 hr |
| Oct 16, 2:31 AM MDT | Fire Weather Watch | BOU | 11 hr |
| Oct 16, 1:36 PM MDT | Red Flag Warning | BOU | 28 hr |
| Oct 24, 2:56 AM MDT | Frost Advisory | BOU | 30 hr |
| Oct 24, 3:04 AM MDT | Red Flag Warning | BOU | 15 hr |
| Oct 28, 2:43 PM MDT | Red Flag Warning | BOU | 27 hr |
| Oct 28, 3:04 PM MDT | Freeze Watch | BOU | 23 hr |
| Oct 29, 1:59 PM MDT | Freeze Warning | BOU | 43 hr |
| Nov 2, 2:34 PM MDT | Winter Weather Advisory | BOU | 43 hr |
| Nov 4, 2:48 PM MST | Winter Storm Watch | BOU | 13 hr |
| Nov 5, 3:38 AM MST | Winter Weather Advisory | BOU | 61 hr |
| Nov 5, 2:17 PM MST | Winter Storm Warning | BOU | 4 days |
| Nov 7, 3:51 AM MST | Winter Storm Watch | BOU | 10 hr |
| Nov 7, 1:43 PM MST | Winter Storm Warning | BOU | 46 hr |
| Nov 8, 12:51 PM MST | Mesoscale Discussion | SPC | 4 hr |
| Nov 25, 1:15 AM MST | Winter Weather Advisory | BOU | 61 hr |
| Dec 9, 10:10 AM MST | Winter Weather Advisory | BOU | 13 hr |
| Dec 28, 2:12 PM MST | High Wind Watch | BOU | 24 hr |
| Dec 28, 2:27 PM MST | Fire Weather Watch | BOU | 13 hr |
| Dec 29, 3:35 AM MST | Red Flag Warning | BOU | 37 hr |
| Dec 29, 2:17 PM MST | High Wind Warning | BOU | 27 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 archive20232025
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.