Alert archive / Utah / San Juan County
Weather alerts in San Juan County, Utah, 2023
125 weather alerts in 2023, 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 2023. Tap one for its archive.
- Alerts
- 125
- Warnings
- 41
- Watches
- 31
- Advisories
- 36
- Busiest month
- August28 alerts
- Busiest day
- February 20, 20235 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, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 3 | 0 | 100% | 0 | ||
| Flash flood warnings | 5 | 0 | 100% | 0 |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Salt Lake City, UT: tornado warnings | 0 | 1 | 0% | |||
| NWS Salt Lake City, UT: severe thunderstorm warnings | 100 | 38 | 62% | 245 | 38% | 22 min |
| NWS Salt Lake City, UT: flash flood warnings | 75 | 31 | 59% | 55 | 64% | 72 min |
| NWS Grand Junction, CO: severe thunderstorm warnings | 14 | 1 | 93% | 26 | 4% | 8 min |
| NWS Grand Junction, CO: flash flood warnings | 13 | 2 | 85% | 3 | 100% | 52 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 9, 1:43 PM MST | Winter Weather Advisory | GJT | 55 hr |
| Jan 13, 2:00 PM MST | Winter Weather Advisory | GJT | 63 hr |
| Jan 16, 2:58 AM MST | Winter Storm Warning | GJT | 56 hr |
| Jan 16, 2:58 AM MST | Winter Weather Advisory | GJT | 62 hr |
| Jan 18, 2:40 PM MST | Winter Weather Advisory | SLC | 50 hr |
| Jan 22, 2:30 AM MST | Winter Weather Advisory | SLC | 33 hr |
| Jan 22, 2:32 AM MST | Winter Weather Advisory | GJT | 38 hr |
| Feb 12, 1:41 PM MST | Winter Storm Watch | SLC | 24 hr |
| Feb 12, 2:09 PM MST | Winter Storm Watch | GJT | 24 hr |
| Feb 13, 2:10 PM MST | Winter Weather Advisory | SLC | 51 hr |
| Feb 13, 2:37 PM MST | Winter Storm Warning | GJT | 51 hr |
| Feb 13, 2:37 PM MST | Winter Weather Advisory | GJT | 51 hr |
| Feb 14, 2:19 AM MST | Winter Storm Warning | SLC | 34 hr |
| Feb 19, 2:40 PM MST | Winter Storm Watch | GJT | 25 hr |
| Feb 19, 2:46 PM MST | High Wind Watch | SLC | 12 hr |
| Feb 20, 2:23 AM MST | High Wind Watch | GJT | 12 hr |
| Feb 20, 2:45 AM MST | High Wind Warning | SLC | 62 hr |
| Feb 20, 2:31 PM MST | Wind Advisory | GJT | 55 hr |
| Feb 20, 3:40 PM MST | Winter Storm Warning | GJT | 4 days |
| Feb 20, 3:40 PM MST | Winter Weather Advisory | GJT | 4 days |
| Feb 22, 8:26 AM MST | Mesoscale Discussion | SPC | 4 hr |
| Feb 23, 6:54 PM MST | Snow Squall Warning | GJT | 36 min |
| Feb 24, 2:03 PM MST | Winter Weather Advisory | SLC | 6 days |
| Feb 25, 2:13 PM MST | Winter Weather Advisory | GJT | 3 days |
| Feb 27, 4:14 PM MST | Winter Storm Watch | GJT | 21 hr |
| Feb 28, 1:41 PM MST | Winter Storm Warning | GJT | 40 hr |
| Feb 28, 1:41 PM MST | Winter Weather Advisory | GJT | 39 hr |
| Mar 4, 2:20 PM MST | Wind Advisory | SLC | 29 hr |
| Mar 4, 2:31 PM MST | Wind Advisory | GJT | 29 hr |
| Mar 9, 2:18 AM MST | Winter Storm Watch | GJT | 11 hr |
| Mar 9, 1:43 PM MST | Winter Storm Warning | GJT | 63 hr |
| Mar 13, 2:50 PM MDT | Winter Storm Watch | GJT | 13 hr |
| Mar 14, 3:23 AM MDT | Winter Storm Warning | GJT | 57 hr |
| Mar 18, 3:05 PM MDT | Winter Storm Watch | GJT | 37 hr |
| Mar 18, 3:05 PM MDT | Winter Weather Advisory | GJT | 65 hr |
| Mar 19, 3:04 PM MDT | Winter Storm Warning | GJT | 3 days |
| Mar 20, 4:18 AM MDT | Winter Storm Warning | GJT | 68 hr |
| Mar 29, 3:24 PM MDT | Wind Advisory | GJT | 27 hr |
| Apr 1, 2:44 AM MDT | High Wind Watch | GJT | 24 hr |
| Apr 1, 4:03 AM MDT | High Wind Watch | SLC | 24 hr |
| Apr 2, 2:27 AM MDT | High Wind Warning | GJT | 45 hr |
| Apr 2, 4:08 AM MDT | High Wind Warning | SLC | 41 hr |
| Apr 2, 2:57 PM MDT | Winter Weather Advisory | GJT | 54 hr |
| Apr 14, 11:21 AM MDT | Special Weather Statement | GJT | 24 min |
| Apr 14, 11:47 AM MDT | Special Weather Statement | GJT | 28 min |
| Apr 17, 1:39 PM MDT | Wind Advisory | GJT | 31 hr |
| Apr 17, 2:56 PM MDT | Wind Advisory | SLC | 29 hr |
| Apr 18, 2:00 PM MDT | Freeze Watch | GJT | 12 hr |
| Apr 19, 2:28 AM MDT | Freeze Warning | GJT | 32 hr |
| Apr 19, 2:48 AM MDT | Freeze Watch | GJT | 11 hr |
| Apr 19, 1:30 PM MDT | Freeze Warning | GJT | 45 hr |
| May 16, 12:38 PM MDT | Special Weather Statement | GJT | 37 min |
| Jun 6, 4:21 PM MDT | Special Weather Statement | GJT | 24 min |
| Jun 16, 3:13 PM MDT | Special Weather Statement | GJT | 32 min |
| Jun 16, 3:46 PM MDT | Special Weather Statement | GJT | 29 min |
| Jun 16, 4:17 PM MDT | Special Weather Statement | GJT | 28 min |
| Jun 18, 2:05 PM MDT | Wind Advisory | GJT | 30 hr |
| Jun 18, 3:14 PM MDT | Wind Advisory | SLC | 32 hr |
| Jun 21, 2:15 PM MDT | Red Flag Warning | GJT | 55 hr |
| Jun 25, 1:59 AM MDT | Fire Weather Watch | GJT | 12 hr |
| Jun 25, 1:59 AM MDT | Fire Weather Watch | GJT | 12 hr |
| Jun 25, 1:29 PM MDT | Red Flag Warning | GJT | 32 hr |
| Jun 25, 1:29 PM MDT | Red Flag Warning | GJT | 56 hr |
| Jun 26, 2:24 PM MDT | Wind Advisory | GJT | 31 hr |
| Jun 27, 2:34 AM MDT | Fire Weather Watch | GJT | 11 hr |
| Jun 27, 1:17 PM MDT | Fire Weather Watch | GJT | 12 hr |
| Jun 27, 1:17 PM MDT | Red Flag Warning | GJT | 31 hr |
| Jun 28, 1:06 AM MDT | Red Flag Warning | GJT | 43 hr |
| Jul 2, 2:59 PM MDT | Fire Weather Watch | GJT | 11 hr |
| Jul 3, 2:13 AM MDT | Red Flag Warning | GJT | 43 hr |
| Jul 5, 2:35 AM MDT | Fire Weather Watch | GJT | 13 hr |
| Jul 5, 3:17 PM MDT | Fire Weather Watch | GJT | 23 hr |
| Jul 5, 3:17 PM MDT | Red Flag Warning | GJT | 31 hr |
| Jul 6, 2:29 PM MDT | Red Flag Warning | GJT | 31 hr |
| Jul 7, 4:00 AM MDT | Fire Weather Watch | GJT | 10 hr |
| Jul 7, 2:07 PM MDT | Red Flag Warning | GJT | 31 hr |
| Jul 12, 2:02 PM MDT | Excessive Heat Warning | SLC | 5 days |
| Jul 14, 2:30 PM MDT | Heat Advisory | GJT | 3 days |
| Jul 18, 3:12 PM MDT | Excessive Heat Watch | SLC | 47 hr |
| Jul 20, 3:09 AM MDT | Excessive Heat Warning | SLC | 5 days |
| Aug 2, 7:40 AM MDT | Flood Watch | SLC | 31 hr |
| Aug 2, 4:14 PM MDT | Special Weather Statement | GJT | 31 min |
| Aug 2, 4:30 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 2, 5:15 PM MDT | Special Weather Statement | GJT | 45 min |
| Aug 2, 5:51 PM MDT | Special Weather Statement | GJT | 24 min |
| Aug 2, 6:02 PM MDT | Areal Flood Advisory | GJT | 118 min |
| Aug 5, 2:26 PM MDT | Fire Weather Watch | GJT | 12 hr |
| Aug 5, 2:26 PM MDT | Fire Weather Watch | GJT | 48 hr |
| Aug 5, 2:26 PM MDT | Red Flag Warning | GJT | 31 hr |
| Aug 6, 2:45 AM MDT | Red Flag Warning | GJT | 42 hr |
| Aug 6, 2:30 PM MDT | Fire Weather Watch | SLC | 22 hr |
| Aug 7, 12:40 PM MDT | Red Flag Warning | SLC | 32 hr |
| Aug 7, 2:09 PM MDT | Red Flag Warning | GJT | 31 hr |
| Aug 14, 3:19 PM MDT | Special Weather Statement | GJT | 26 min |
| Aug 14, 3:24 PM MDT | Special Weather Statement | GJT | 36 min |
| Aug 14, 5:11 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 15, 2:39 PM MDT | Flash Flood Watch | GJT | 5 hr |
| Aug 16, 3:48 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 17, 11:35 AM MDT | Flood Watch | SLC | 6 days |
| Aug 17, 3:13 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 17, 4:42 PM MDT | Flash Flood Warning | GJT | 2 hr |
| Aug 17, 7:47 PM MDT | Flash Flood Warning | GJT | 118 min |
| Aug 18, 5:16 PM MDT | Special Weather Statement | GJT | 29 min |
| Aug 20, 2:41 AM MDT | Flood Watch | SLC | 8 hr |
| Aug 21, 3:47 PM MDT | Severe Thunderstorm Warning | SLC | 28 min |
| Aug 21, 4:13 PM MDT | Severe Thunderstorm Warning | SLC | 32 min |
| Aug 26, 1:47 PM MDT | Areal Flood Advisory | GJT | 107 min |
| Aug 27, 1:37 PM MDT | Areal Flood Advisory | GJT | 113 min |
| Sep 12, 1:08 PM MDT | Special Weather Statement | GJT | 37 min |
| Sep 15, 4:01 PM MDT | Special Weather Statement | GJT | 29 min |
| Sep 18, 3:05 PM MDT | Severe Thunderstorm Warning | GJT | 25 min |
| Sep 19, 1:36 PM MDT | Special Weather Statement | GJT | 24 min |
| Sep 19, 3:12 PM MDT | Areal Flood Advisory | GJT | 107 min |
| Sep 28, 1:41 PM MDT | Fire Weather Watch | GJT | 24 hr |
| Sep 29, 1:44 PM MDT | Red Flag Warning | GJT | 30 hr |
| Sep 30, 2:14 PM MDT | Wind Advisory | GJT | 29 hr |
| Oct 10, 2:06 PM MDT | Wind Advisory | GJT | 29 hr |
| Oct 28, 1:13 PM MDT | Freeze Watch | GJT | 14 hr |
| Oct 29, 2:50 AM MDT | Freeze Warning | GJT | 33 hr |
| Nov 18, 2:43 PM MST | Winter Weather Advisory | GJT | 38 hr |
| Nov 22, 2:39 AM MST | Winter Weather Advisory | GJT | 3 days |
| Nov 23, 1:58 AM MST | Winter Storm Warning | GJT | 57 hr |
| Dec 16, 9:09 PM MST | Dense Fog Advisory | GJT | 39 hr |
| Dec 18, 12:04 PM MST | Dense Fog Advisory | GJT | 4 hr |
| Dec 21, 2:38 PM MST | Winter Weather Advisory | GJT | 68 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 Warning | 3 |
| Mesoscale Discussion | 1 |
| Special Weather Statement | 16 |
| Flooding | |
| Flash Flood Warning | 5 |
| Flash Flood Watch | 1 |
| Flood Watch | 3 |
| Areal Flood Advisory | 5 |
| Winter | |
| Snow Squall Warning | 1 |
| Winter Storm Warning | 10 |
| Winter Storm Watch | 7 |
| Winter Weather Advisory | 17 |
| Heat | |
| Excessive Heat Warning | 2 |
| Excessive Heat Watch | 1 |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 3 |
| Freeze Watch | 3 |
| Wind and dust | |
| High Wind Warning | 3 |
| High Wind Watch | 4 |
| Wind Advisory | 11 |
| Fire | |
| Red Flag Warning | 14 |
| Fire Weather Watch | 12 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20222024
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.