Alert archive / Utah / San Juan County
Weather alerts in San Juan County, Utah, 2008
66 weather alerts in 2008, 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 2008. Tap one for its archive.
- Alerts
- 66
- Warnings
- 23
- Watches
- 16
- Advisories
- 24
- Busiest month
- January12 alerts
- Busiest day
- February 2, 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.
San Juan County, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 2 | 0 | 100% | 0 | ||
| Flash flood warnings | 6 | 0 | 100% | 0 |
Each office's whole area, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Salt Lake City, UT: severe thunderstorm warnings | 62 | 8 | 87% | 45 | 22% | 25 min |
| NWS Salt Lake City, UT: flash flood warnings | 36 | 10 | 72% | 29 | 45% | 93 min |
| NWS Grand Junction, CO: tornado warnings | 0 | 1 | 0% | |||
| NWS Grand Junction, CO: severe thunderstorm warnings | 8 | 0 | 100% | 4 | 0% | |
| NWS Grand Junction, CO: flash flood warnings | 16 | 1 | 94% | 2 | 50% | 58 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 3, 4:20 AM MST | Winter Storm Watch | GJT | 35 hr |
| Jan 4, 4:04 AM MST | Winter Storm Warning | GJT | 4 days |
| Jan 5, 1:44 PM MST | Heavy Snow Warning | GJT | 55 hr |
| Jan 5, 1:44 PM MST | Snow Advisory | GJT | 52 hr |
| Jan 6, 3:01 PM MST | Snow and Blowing Snow Advisory | GJT | 14 hr |
| Jan 23, 3:59 AM MST | Winter Storm Watch | GJT | 25 hr |
| Jan 23, 3:37 PM MST | Winter Storm Warning | GJT | 44 hr |
| Jan 25, 3:46 PM MST | Winter Storm Watch | GJT | 43 hr |
| Jan 26, 3:28 PM MST | Winter Storm Warning | GJT | 57 hr |
| Jan 27, 4:09 AM MST | Snow Advisory | GJT | 41 hr |
| Jan 28, 11:06 AM MST | Mesoscale Discussion | SPC | 6 hr |
| Jan 29, 4:18 AM MST | Snow and Blowing Snow Advisory | GJT | 44 hr |
| Feb 2, 9:08 AM MST | Snow Advisory | GJT | 9 hr |
| Feb 2, 3:41 PM MST | Heavy Snow Warning | GJT | 48 hr |
| Feb 2, 3:41 PM MST | Winter Storm Warning | GJT | 56 hr |
| Feb 13, 4:29 AM MST | Snow and Blowing Snow Advisory | GJT | 50 hr |
| Feb 20, 4:00 AM MST | Snow Advisory | GJT | 35 hr |
| Feb 21, 3:33 PM MST | Snow Advisory | GJT | 44 hr |
| Feb 23, 11:00 PM MST | Snow and Blowing Snow Advisory | GJT | 34 hr |
| Mar 16, 4:16 AM MDT | Snow and Blowing Snow Advisory | GJT | 32 hr |
| Apr 8, 3:38 AM MDT | Winter Storm Watch | GJT | 24 hr |
| Apr 8, 3:13 PM MDT | Winter Storm Warning | GJT | 48 hr |
| Apr 14, 2:43 PM MDT | Wind Advisory | GJT | 30 hr |
| Apr 19, 3:03 PM MDT | Wind Advisory | GJT | 30 hr |
| Apr 29, 3:19 PM MDT | Freeze Watch | GJT | 36 hr |
| May 1, 3:21 AM MDT | Freeze Warning | GJT | 29 hr |
| May 8, 11:56 AM MDT | Mesoscale Discussion | SPC | 64 min |
| May 8, 12:30 PM MDT | Severe Thunderstorm Warning | SLC | 30 min |
| May 8, 12:43 PM MDT | Severe Thunderstorm Warning | GJT | 33 min |
| May 20, 11:27 AM MDT | River Flood Advisory | GJT | 5 days |
| May 21, 4:30 AM MDT | Winter Storm Warning | GJT | 3 days |
| May 21, 10:51 AM MDT | River Flood Advisory | GJT | 3 days |
| Jun 4, 3:00 PM MDT | Snow Advisory | GJT | 27 hr |
| Jun 10, 4:48 AM MDT | Wind Advisory | GJT | 15 hr |
| Jul 22, 7:56 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 25, 3:10 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 27, 1:48 PM MDT | Areal Flood Advisory | GJT | 93 min |
| Aug 5, 3:34 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Aug 6, 4:34 AM MDT | Flash Flood Watch | GJT | 16 hr |
| Aug 6, 4:18 PM MDT | Flash Flood Warning | SLC | 3 hr |
| Aug 7, 4:25 AM MDT | Flash Flood Watch | GJT | 16 hr |
| Aug 7, 2:19 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 8, 4:30 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Aug 8, 5:03 PM MDT | Flash Flood Warning | SLC | 5 hr |
| Aug 8, 5:19 PM MDT | Flash Flood Warning | SLC | 3 hr |
| Aug 8, 8:04 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 9, 4:27 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Aug 18, 2:32 PM MDT | Flash Flood Warning | SLC | 3 hr |
| Sep 11, 12:44 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 4, 5:13 AM MDT | Winter Storm Warning | GJT | 47 hr |
| Oct 11, 4:14 AM MDT | Wind Advisory | GJT | 17 hr |
| Oct 12, 3:00 AM MDT | Freeze Watch | GJT | 13 hr |
| Oct 12, 3:30 PM MDT | Freeze Warning | GJT | 18 hr |
| Nov 26, 3:44 AM MST | Winter Weather Advisory | GJT | 62 hr |
| Dec 11, 3:35 PM MST | Winter Storm Watch | GJT | 19 hr |
| Dec 12, 10:53 AM MST | Winter Storm Warning | GJT | 52 hr |
| Dec 13, 3:27 PM MST | Winter Storm Watch | GJT | 23 hr |
| Dec 14, 2:37 PM MST | Winter Storm Warning | GJT | 5 days |
| Dec 14, 2:37 PM MST | Winter Weather Advisory | GJT | 51 hr |
| Dec 16, 3:58 PM MST | Winter Storm Watch | GJT | 23 hr |
| Dec 17, 2:35 PM MST | Winter Weather Advisory | GJT | 27 hr |
| Dec 20, 3:14 PM MST | Winter Storm Watch | GJT | 35 hr |
| Dec 21, 4:41 AM MST | Winter Storm Warning | GJT | 67 hr |
| Dec 21, 3:29 PM MST | Winter Weather Advisory | GJT | 48 hr |
| Dec 23, 4:15 AM MST | Winter Storm Watch | GJT | 35 hr |
| Dec 23, 3:37 PM MST | Winter Storm Warning | GJT | 3 days |
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 | 2 |
| Mesoscale Discussion | 3 |
| Flooding | |
| Flash Flood Warning | 6 |
| Flash Flood Watch | 5 |
| Areal Flood Advisory | 3 |
| River Flood Advisory | 2 |
| Winter | |
| Heavy Snow Warning | 2 |
| Winter Storm Warning | 11 |
| Winter Storm Watch | 9 |
| Snow Advisory | 6 |
| Snow and Blowing Snow Advisory | 5 |
| Winter Weather Advisory | 4 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 2 |
| Wind and dust | |
| Wind Advisory | 4 |
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.