Alert archive / Colorado / San Juan County
Weather alerts in San Juan County, Colorado, 2011
60 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
San Juan County and its neighbors
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Alerts
- 60
- Warnings
- 16
- Watches
- 16
- Advisories
- 26
- Busiest month
- February10 alerts
- Busiest day
- February 16, 20113 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
San Juan County, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 0 | 1 | 0% | |||
| Flash flood warnings | 1 | 0 | 100% | 1 | 0% |
Each office's whole area, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Junction, CO: tornado warnings | 2 | 1 | 50% | 1 | 100% | 6 min |
| NWS Grand Junction, CO: severe thunderstorm warnings | 30 | 6 | 80% | 26 | 42% | 18 min |
| NWS Grand Junction, CO: flash flood warnings | 37 | 3 | 92% | 24 | 13% | 28 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 8, 2:42 AM MST | Winter Weather Advisory | GJT | 49 hr |
| Jan 30, 3:35 AM MST | Winter Weather Advisory | GJT | 3 days |
| Feb 6, 2:28 PM MST | Winter Weather Advisory | GJT | 54 hr |
| Feb 15, 2:59 PM MST | Blizzard Watch | GJT | 14 hr |
| Feb 15, 3:00 PM MST | High Wind Warning | GJT | 33 hr |
| Feb 16, 5:12 AM MST | Blizzard Warning | GJT | 23 hr |
| Feb 16, 5:12 AM MST | Winter Weather Advisory | GJT | 39 hr |
| Feb 16, 5:29 AM MST | Wind Advisory | GJT | 19 hr |
| Feb 17, 3:04 PM MST | Winter Storm Watch | GJT | 37 hr |
| Feb 18, 1:04 PM MST | Winter Storm Warning | GJT | 59 hr |
| Feb 24, 3:56 AM MST | Winter Storm Warning | GJT | 3 days |
| Feb 24, 2:16 PM MST | Winter Storm Watch | GJT | 12 hr |
| Mar 5, 4:12 AM MST | Winter Weather Advisory | GJT | 50 hr |
| Mar 5, 2:15 PM MST | Winter Storm Watch | GJT | 38 hr |
| Mar 6, 3:01 PM MST | Winter Storm Warning | GJT | 51 hr |
| Mar 20, 2:35 PM MDT | Wind Advisory | GJT | 30 hr |
| Mar 20, 3:02 PM MDT | Winter Weather Advisory | GJT | 57 hr |
| Mar 26, 4:22 AM MDT | Winter Weather Advisory | GJT | 34 hr |
| Apr 2, 4:25 AM MDT | Winter Weather Advisory | GJT | 48 hr |
| Apr 6, 3:15 AM MDT | Winter Weather Advisory | GJT | 33 hr |
| Apr 8, 4:40 AM MDT | Winter Storm Watch | GJT | 22 hr |
| Apr 8, 10:01 AM MDT | Winter Storm Warning | GJT | 62 hr |
| Apr 22, 4:30 AM MDT | Winter Storm Watch | GJT | 11 hr |
| Apr 22, 3:00 PM MDT | Winter Storm Warning | GJT | 63 hr |
| Apr 25, 3:00 PM MDT | Winter Weather Advisory | GJT | 33 hr |
| Apr 30, 2:13 PM MDT | Winter Weather Advisory | GJT | 34 hr |
| May 9, 3:13 PM MDT | Winter Storm Watch | GJT | 13 hr |
| May 10, 3:48 AM MDT | Winter Storm Warning | GJT | 44 hr |
| May 10, 3:48 AM MDT | Winter Weather Advisory | GJT | 44 hr |
| May 17, 3:00 PM MDT | Winter Weather Advisory | GJT | 17 hr |
| May 18, 6:17 AM MDT | Winter Weather Advisory | GJT | 8 hr |
| May 18, 2:01 PM MDT | Winter Storm Warning | GJT | 58 hr |
| Jun 19, 2:03 PM MDT | Winter Weather Advisory | GJT | 25 hr |
| Jun 30, 8:51 AM MDT | Mesoscale Discussion | SPC | 54 min |
| Jun 30, 9:06 AM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 1:35 PM MDT | Special Weather Statement | GJT | 55 min |
| Jul 11, 3:21 AM MDT | Flash Flood Watch | GJT | 45 hr |
| Jul 18, 6:27 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 19, 4:45 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Jul 25, 9:03 PM MDT | Flash Flood Watch | GJT | 25 hr |
| Aug 2, 4:40 AM MDT | Flash Flood Watch | GJT | 16 hr |
| Aug 4, 2:31 PM MDT | Areal Flood Advisory | GJT | 118 min |
| Aug 11, 1:46 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 28, 5:53 PM MDT | Areal Flood Advisory | GJT | 2 hr |
| Sep 14, 5:00 AM MDT | Winter Weather Advisory | GJT | 24 hr |
| Oct 4, 4:51 AM MDT | Winter Storm Watch | GJT | 33 hr |
| Oct 5, 5:34 AM MDT | Winter Storm Warning | GJT | 39 hr |
| Oct 23, 10:55 PM MDT | Winter Storm Watch | GJT | 24 hr |
| Oct 24, 10:52 PM MDT | Winter Storm Warning | GJT | 46 hr |
| Nov 3, 4:37 AM MDT | Winter Storm Watch | GJT | 17 hr |
| Nov 3, 2:20 PM MDT | Winter Storm Warning | GJT | 58 hr |
| Nov 6, 2:55 PM MST | Winter Weather Advisory | GJT | 33 hr |
| Nov 10, 3:04 PM MST | Winter Storm Watch | GJT | 24 hr |
| Nov 11, 3:00 PM MST | Winter Weather Advisory | GJT | 51 hr |
| Nov 21, 8:45 AM MST | Winter Weather Advisory | GJT | 9 hr |
| Dec 2, 4:24 AM MST | Winter Storm Warning | GJT | 43 hr |
| Dec 11, 3:13 PM MST | Winter Storm Watch | GJT | 11 hr |
| Dec 12, 2:10 AM MST | Winter Storm Warning | GJT | 58 hr |
| Dec 20, 3:37 PM MST | Winter Weather Advisory | GJT | 52 hr |
| Dec 31, 9:30 AM MST | High Wind Warning | GJT | 5 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 Watch | 1 |
| Mesoscale Discussion | 1 |
| Special Weather Statement | 1 |
| Flooding | |
| Flash Flood Warning | 1 |
| Flash Flood Watch | 3 |
| Areal Flood Advisory | 4 |
| Winter | |
| Blizzard Warning | 1 |
| Winter Storm Warning | 12 |
| Blizzard Watch | 1 |
| Winter Storm Watch | 11 |
| Winter Weather Advisory | 20 |
| Wind and dust | |
| High Wind Warning | 2 |
| Wind Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20102012
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.