Alert archive / Colorado / Jefferson County
Weather alerts in Jefferson County, Colorado, 2008
113 weather alerts in 2008, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Jefferson County and its neighbors
Each county as a circle sized by its count in 2008. Tap one for its archive.
- Alerts
- 113
- Warnings
- 35
- Watches
- 24
- Advisories
- 51
- Busiest month
- April19 alerts
- Busiest day
- February 6, 20083 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Jefferson County, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 3 | 2 | 33% | 4 | 75% | 7 min |
| Flash flood warnings | 1 | 1 | 0% | 0 |
Each office's whole area, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Denver/Boulder, CO: tornado warnings | 58 | 16 | 72% | 44 | 64% | 13 min |
| NWS Denver/Boulder, CO: severe thunderstorm warnings | 147 | 52 | 65% | 140 | 54% | 20 min |
| NWS Denver/Boulder, CO: flash flood warnings | 14 | 3 | 79% | 7 | 86% | 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 |
|---|---|---|---|
| Dec 31, 8:19 PM MST | Blowing Snow Advisory | BOU | 14 hr |
| Jan 4, 2:12 PM MST | Snow and Blowing Snow Advisory | BOU | 6 hr |
| Jan 4, 2:12 PM MST | Winter Storm Warning | BOU | 40 hr |
| Jan 4, 8:14 PM MST | High Wind Warning | BOU | 15 hr |
| Jan 6, 5:52 AM MST | Snow Advisory | BOU | 41 hr |
| Jan 8, 2:12 PM MST | Snow and Blowing Snow Advisory | BOU | 33 hr |
| Jan 10, 11:40 PM MST | Snow and Blowing Snow Advisory | BOU | 16 hr |
| Jan 15, 3:55 PM MST | Snow and Blowing Snow Advisory | BOU | 13 hr |
| Jan 26, 1:57 PM MST | Winter Storm Watch | BOU | 22 hr |
| Jan 27, 11:52 AM MST | Snow and Blowing Snow Advisory | BOU | 41 hr |
| Jan 29, 1:44 PM MST | Snow and Blowing Snow Advisory | BOU | 27 hr |
| Jan 31, 2:24 PM MST | Blowing Snow Advisory | BOU | 22 hr |
| Jan 31, 2:24 PM MST | Snow and Blowing Snow Advisory | BOU | 28 hr |
| Feb 4, 4:56 AM MST | Snow Advisory | BOU | 23 hr |
| Feb 5, 2:56 PM MST | High Wind Watch | BOU | 24 hr |
| Feb 6, 5:20 AM MST | Winter Storm Watch | BOU | 10 hr |
| Feb 6, 3:20 PM MST | High Wind Warning | BOU | 26 hr |
| Feb 6, 3:24 PM MST | Winter Storm Warning | BOU | 38 hr |
| Feb 8, 5:08 AM MST | High Wind Watch | BOU | 10 hr |
| Feb 8, 5:12 AM MST | Snow and Blowing Snow Advisory | BOU | 24 hr |
| Feb 8, 5:12 AM MST | Winter Storm Warning | BOU | 4 hr |
| Feb 13, 3:43 PM MST | Blowing Snow Advisory | BOU | 53 min |
| Feb 13, 4:36 PM MST | Snow and Blowing Snow Advisory | BOU | 24 hr |
| Feb 24, 4:25 AM MST | Snow and Blowing Snow Advisory | BOU | 9 hr |
| Feb 24, 4:25 AM MST | Winter Storm Warning | BOU | 25 hr |
| Mar 1, 4:54 AM MST | Red Flag Warning | BOU | 13 hr |
| Mar 1, 3:56 PM MST | Snow and Blowing Snow Advisory | BOU | 28 hr |
| Mar 1, 9:51 PM MST | Winter Storm Warning | BOU | 22 hr |
| Mar 13, 4:13 AM MDT | Snow and Blowing Snow Advisory | BOU | 24 hr |
| Mar 14, 4:25 AM MDT | Snow Advisory | BOU | 11 hr |
| Mar 15, 12:14 PM MDT | Winter Storm Watch | BOU | 26 hr |
| Mar 16, 1:47 PM MDT | Heavy Snow Warning | BOU | 19 hr |
| Mar 17, 9:04 AM MDT | Snow Advisory | BOU | 4 hr |
| Mar 30, 5:03 AM MDT | Snow Advisory | BOU | 37 hr |
| Apr 7, 5:49 AM MDT | Snow Advisory | BOU | 15 hr |
| Apr 7, 9:46 AM MDT | Snow and Blowing Snow Advisory | BOU | 11 hr |
| Apr 8, 3:06 PM MDT | Winter Storm Watch | BOU | 22 hr |
| Apr 9, 12:40 PM MDT | Snow and Blowing Snow Advisory | BOU | 27 hr |
| Apr 9, 12:40 PM MDT | Winter Storm Warning | BOU | 33 hr |
| Apr 10, 3:49 PM MDT | Snow and Blowing Snow Advisory | BOU | 26 hr |
| Apr 14, 4:05 AM MDT | Fire Weather Watch | BOU | 11 hr |
| Apr 14, 2:59 PM MDT | Red Flag Warning | BOU | 28 hr |
| Apr 15, 3:16 PM MDT | Winter Storm Watch | BOU | 13 hr |
| Apr 16, 4:00 AM MDT | Winter Storm Warning | BOU | 25 hr |
| Apr 16, 11:15 AM MDT | Snow Advisory | BOU | 8 hr |
| Apr 19, 10:17 AM MDT | Red Flag Warning | BOU | 10 hr |
| Apr 19, 8:00 PM MDT | Red Flag Warning | BOU | 24 hr |
| Apr 21, 3:21 PM MDT | Fire Weather Watch | BOU | 24 hr |
| Apr 22, 3:47 PM MDT | Red Flag Warning | BOU | 29 hr |
| Apr 28, 3:53 PM MDT | Fire Weather Watch | BOU | 12 hr |
| Apr 29, 4:01 AM MDT | Red Flag Warning | BOU | 16 hr |
| Apr 29, 8:23 PM MDT | Red Flag Warning | BOU | 24 hr |
| Apr 30, 4:50 PM MDT | Winter Storm Warning | BOU | 47 hr |
| May 1, 3:50 PM MDT | High Wind Watch | BOU | 12 hr |
| May 2, 8:36 PM MDT | Freeze Warning | BOU | 12 hr |
| May 10, 2:22 PM MDT | Freeze Warning | BOU | 18 hr |
| May 11, 3:30 PM MDT | Winter Storm Watch | BOU | 25 hr |
| May 12, 4:35 PM MDT | Snow Advisory | BOU | 23 hr |
| May 14, 4:31 PM MDT | Snow Advisory | BOU | 12 hr |
| May 22, 11:25 AM MDT | Tornado Watch | SPC | 9 hr |
| May 22, 12:34 PM MDT | Mesoscale Discussion | SPC | 86 min |
| May 22, 4:50 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jun 4, 2:58 PM MDT | Severe Thunderstorm Warning | BOU | 47 min |
| Jun 9, 3:51 PM MDT | Red Flag Warning | BOU | 28 hr |
| Jun 12, 12:19 PM MDT | Red Flag Warning | BOU | 9 hr |
| Jun 19, 6:22 PM MDT | Severe Thunderstorm Watch | SPC | 27 hr |
| Jun 20, 6:08 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Jun 25, 8:38 PM MDT | Severe Thunderstorm Warning | BOU | 37 min |
| Jul 25, 2:12 PM MDT | Areal Flood Advisory | BOU | 93 min |
| Jul 31, 3:55 PM MDT | Heat Advisory | BOU | 29 hr |
| Aug 2, 10:43 AM MDT | Heat Advisory | BOU | 9 hr |
| Aug 2, 11:52 AM MDT | Severe Thunderstorm Warning | BOU | 23 min |
| Aug 5, 2:05 PM MDT | Areal Flood Advisory | BOU | 85 min |
| Aug 5, 6:25 PM MDT | Areal Flood Advisory | BOU | 80 min |
| Aug 6, 11:52 AM MDT | Flash Flood Watch | BOU | 12 hr |
| Aug 6, 5:03 PM MDT | Areal Flood Advisory | BOU | 87 min |
| Aug 6, 7:20 PM MDT | Areal Flood Advisory | BOU | 85 min |
| Aug 7, 11:37 AM MDT | Flash Flood Watch | BOU | 8 hr |
| Aug 8, 7:30 PM MDT | Areal Flood Advisory | BOU | 90 min |
| Aug 9, 11:40 AM MDT | Flash Flood Watch | BOU | 8 hr |
| Aug 9, 5:42 PM MDT | Areal Flood Advisory | BOU | 3 hr |
| Aug 10, 4:10 AM MDT | Flash Flood Watch | BOU | 16 hr |
| Aug 15, 2:32 PM MDT | Flood Watch | BOU | 32 hr |
| Aug 24, 6:56 PM MDT | Flash Flood Warning | BOU | 109 min |
| Oct 6, 11:13 AM MDT | Frost Advisory | BOU | 22 hr |
| Oct 11, 2:37 AM MDT | Dense Fog Advisory | BOU | 12 hr |
| Oct 11, 5:17 AM MDT | Winter Weather Advisory | BOU | 25 hr |
| Oct 12, 8:07 PM MDT | Freeze Warning | BOU | 13 hr |
| Oct 13, 2:47 PM MDT | Freeze Warning | BOU | 18 hr |
| Oct 22, 4:02 AM MDT | Freeze Warning | BOU | 29 hr |
| Nov 4, 5:16 AM MST | Winter Weather Advisory | BOU | 43 hr |
| Nov 11, 2:49 PM MST | High Wind Watch | BOU | 24 hr |
| Nov 12, 5:11 AM MST | Winter Storm Watch | BOU | 22 hr |
| Nov 12, 5:11 AM MST | Winter Weather Advisory | BOU | 53 hr |
| Nov 20, 2:46 AM MST | Winter Weather Advisory | BOU | 11 hr |
| Nov 29, 4:27 AM MST | Winter Weather Advisory | BOU | 8 hr |
| Nov 29, 12:48 PM MST | Winter Storm Warning | BOU | 34 hr |
| Dec 4, 2:32 AM MST | Winter Weather Advisory | BOU | 17 hr |
| Dec 4, 8:57 PM MST | Dense Fog Advisory | BOU | 6 hr |
| Dec 7, 9:31 AM MST | Winter Storm Watch | BOU | 20 hr |
| Dec 8, 5:49 AM MST | Winter Weather Advisory | BOU | 23 hr |
| Dec 8, 10:23 PM MST | Winter Storm Warning | BOU | 7 hr |
| Dec 13, 3:54 AM MST | Winter Storm Warning | BOU | 31 hr |
| Dec 14, 12:34 AM MST | Winter Weather Advisory | BOU | 15 hr |
| Dec 14, 4:04 PM MST | Winter Storm Watch | BOU | 24 hr |
| Dec 15, 4:03 PM MST | Winter Storm Warning | BOU | 18 hr |
| Dec 17, 3:00 PM MST | Winter Weather Advisory | BOU | 29 hr |
| Dec 18, 5:32 PM MST | High Wind Warning | BOU | 10 hr |
| Dec 19, 4:01 AM MST | Winter Weather Advisory | BOU | 37 hr |
| Dec 22, 3:52 PM MST | Winter Weather Advisory | BOU | 24 hr |
| Dec 25, 3:17 AM MST | Winter Weather Advisory | BOU | 38 hr |
| Dec 28, 10:45 AM MST | High Wind Watch | BOU | 24 hr |
| Dec 29, 10:30 AM MST | High Wind Warning | BOU | 22 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 archive20072009
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.