Alert archive / Utah / San Juan County
Weather alerts in San Juan County, Utah, 2015
145 weather alerts in 2015, 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 2015. Tap one for its archive.
- Alerts
- 145
- Warnings
- 53
- Watches
- 15
- Advisories
- 39
- Busiest month
- June39 alerts
- Busiest day
- June 6, 201512 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
1 of 1 tornado warnings covering San Juan County in 2015 had a tornado report inside them; 1 of 2 tornado reports fell inside a warning, on average 25 minutes after it went out.
San Juan County, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 1 | 0% | 2 | 50% | 25 min |
| Severe thunderstorm warnings | 22 | 1 | 95% | 3 | 33% | 8 min |
| Flash flood warnings | 10 | 1 | 90% | 3 | 0% |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Junction, CO: tornado warnings | 3 | 1 | 67% | 3 | 33% | 25 min |
| NWS Grand Junction, CO: severe thunderstorm warnings | 45 | 7 | 84% | 22 | 27% | 20 min |
| NWS Grand Junction, CO: flash flood warnings | 17 | 3 | 82% | 19 | 16% | 51 min |
| NWS Salt Lake City, UT: severe thunderstorm warnings | 83 | 14 | 83% | 114 | 46% | 37 min |
| NWS Salt Lake City, UT: flash flood warnings | 70 | 21 | 70% | 35 | 66% | 110 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, 2:21 AM MST | Dense Fog Advisory | GJT | 7 hr |
| Jan 11, 9:07 AM MST | Dense Fog Advisory | GJT | 3 hr |
| Jan 11, 3:04 PM MST | Winter Storm Warning | GJT | 51 hr |
| Jan 11, 3:04 PM MST | Winter Weather Advisory | GJT | 51 hr |
| Jan 14, 4:56 AM MST | Dense Fog Advisory | GJT | 4 hr |
| Jan 14, 11:50 PM MST | Dense Fog Advisory | GJT | 9 hr |
| Jan 17, 1:36 AM MST | Dense Fog Advisory | GJT | 9 hr |
| Jan 17, 2:53 PM MST | Dense Fog Advisory | GJT | 21 hr |
| Jan 29, 3:29 PM MST | Winter Weather Advisory | GJT | 50 hr |
| Jan 31, 8:50 PM MST | Dense Fog Advisory | GJT | 13 hr |
| Feb 20, 4:42 AM MST | Winter Storm Warning | GJT | 4 days |
| Feb 20, 4:42 AM MST | Winter Weather Advisory | GJT | 3 days |
| Feb 20, 4:47 PM MST | Winter Storm Watch | GJT | 23 hr |
| Feb 24, 7:50 PM MST | Dense Fog Advisory | GJT | 8 hr |
| Feb 25, 2:36 PM MST | Winter Storm Watch | GJT | 24 hr |
| Feb 26, 2:12 PM MST | Winter Storm Warning | GJT | 6 days |
| Apr 1, 2:05 PM MDT | Freeze Watch | GJT | 13 hr |
| Apr 2, 3:34 AM MDT | Freeze Warning | GJT | 29 hr |
| Apr 2, 11:14 AM MDT | Freeze Warning | GJT | 46 hr |
| Apr 7, 4:32 AM MDT | Freeze Watch | GJT | 23 hr |
| Apr 8, 3:21 AM MDT | Freeze Warning | GJT | 29 hr |
| Apr 13, 4:35 AM MDT | High Wind Watch | GJT | 17 hr |
| Apr 13, 2:56 PM MDT | Freeze Watch | GJT | 36 hr |
| Apr 13, 2:56 PM MDT | High Wind Warning | GJT | 36 hr |
| Apr 13, 2:56 PM MDT | Wind Advisory | GJT | 36 hr |
| Apr 15, 3:05 AM MDT | Freeze Warning | GJT | 30 hr |
| Apr 16, 4:11 AM MDT | Winter Storm Warning | GJT | 68 hr |
| Apr 25, 2:51 PM MDT | Winter Storm Warning | GJT | 37 hr |
| May 8, 4:44 PM MDT | Special Weather Statement | GJT | 46 min |
| May 14, 11:56 AM MDT | Mesoscale Discussion | SPC | 3 hr |
| May 14, 1:07 PM MDT | Flash Flood Warning | SLC | 3 hr |
| May 14, 1:50 PM MDT | Special Weather Statement | GJT | 40 min |
| May 14, 2:40 PM MDT | Severe Thunderstorm Warning | GJT | 17 min |
| May 14, 2:43 PM MDT | Special Weather Statement | GJT | 32 min |
| May 14, 2:58 PM MDT | Winter Weather Advisory | GJT | 66 hr |
| May 19, 8:33 AM MDT | Special Weather Statement | GJT | 42 min |
| May 26, 1:42 PM MDT | Special Weather Statement | GJT | 48 min |
| Jun 3, 5:55 PM MDT | Flash Flood Watch | GJT | 5 days |
| Jun 5, 12:54 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jun 5, 1:36 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 5, 1:47 PM MDT | Severe Thunderstorm Warning | SLC | 28 min |
| Jun 6, 1:29 PM MDT | Severe Thunderstorm Warning | SLC | 46 min |
| Jun 6, 1:45 PM MDT | Severe Thunderstorm Warning | GJT | 30 min |
| Jun 6, 2:00 PM MDT | Severe Thunderstorm Warning | SLC | 45 min |
| Jun 6, 2:16 PM MDT | Severe Thunderstorm Warning | SLC | 15 min |
| Jun 6, 2:28 PM MDT | Special Weather Statement | GJT | 32 min |
| Jun 6, 2:44 PM MDT | Severe Thunderstorm Warning | SLC | 46 min |
| Jun 6, 3:11 PM MDT | Severe Thunderstorm Warning | GJT | 19 min |
| Jun 6, 3:34 PM MDT | Severe Thunderstorm Warning | GJT | 15 min |
| Jun 6, 4:19 PM MDT | Special Weather Statement | GJT | 41 min |
| Jun 6, 5:13 PM MDT | Areal Flood Advisory | GJT | 6 hr |
| Jun 6, 5:18 PM MDT | Special Weather Statement | GJT | 42 min |
| Jun 6, 5:59 PM MDT | Special Weather Statement | GJT | 46 min |
| Jun 6, 6:04 PM MDT | Special Weather Statement | GJT | 41 min |
| Jun 6, 6:07 PM MDT | Severe Thunderstorm Warning | GJT | 23 min |
| Jun 6, 6:25 PM MDT | Tornado Warning | GJT | 35 min |
| Jun 6, 6:30 PM MDT | Severe Thunderstorm Warning | GJT | 45 min |
| Jun 6, 6:39 PM MDT | Special Weather Statement | GJT | 51 min |
| Jun 6, 7:07 PM MDT | Severe Thunderstorm Warning | GJT | 38 min |
| Jun 6, 7:43 PM MDT | Severe Thunderstorm Warning | GJT | 47 min |
| Jun 6, 8:25 PM MDT | Severe Thunderstorm Warning | GJT | 35 min |
| Jun 6, 9:02 PM MDT | Severe Thunderstorm Warning | GJT | 28 min |
| Jun 6, 10:05 PM MDT | Areal Flood Advisory | GJT | 6 hr |
| Jun 7, 4:01 PM MDT | Special Weather Statement | GJT | 59 min |
| Jun 9, 2:46 PM MDT | Flash Flood Watch | GJT | 3 days |
| Jun 10, 10:57 PM MDT | Special Weather Statement | GJT | 48 min |
| Jun 10, 11:07 PM MDT | Special Weather Statement | GJT | 38 min |
| Jun 10, 11:12 PM MDT | Severe Thunderstorm Warning | GJT | 33 min |
| Jun 10, 11:12 PM MDT | Severe Thunderstorm Warning | GJT | 33 min |
| Jun 10, 11:40 PM MDT | Severe Thunderstorm Warning | GJT | 35 min |
| Jun 11, 12:57 AM MDT | Severe Thunderstorm Warning | GJT | 33 min |
| Jun 11, 1:03 AM MDT | Flash Flood Warning | GJT | 3 hr |
| Jun 11, 1:07 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jun 11, 1:32 PM MDT | Mesoscale Discussion | SPC | 118 min |
| Jun 11, 2:17 PM MDT | Flash Flood Warning | GJT | 6 hr |
| Jun 28, 1:36 PM MDT | Special Weather Statement | GJT | 39 min |
| Jul 2, 2:53 PM MDT | Special Weather Statement | GJT | 52 min |
| Jul 2, 6:50 PM MDT | Special Weather Statement | GJT | 25 min |
| Jul 3, 2:09 PM MDT | Special Weather Statement | GJT | 36 min |
| Jul 3, 2:27 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 3, 2:38 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 4, 8:20 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 4, 10:10 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Jul 5, 2:07 PM MDT | Areal Flood Warning | GJT | 3 hr |
| Jul 5, 3:15 PM MDT | Special Weather Statement | GJT | 45 min |
| Jul 6, 2:55 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 6, 7:00 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 7, 12:50 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 7, 7:54 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 8, 2:26 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Jul 8, 3:29 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 8, 4:58 PM MDT | Special Weather Statement | GJT | 32 min |
| Jul 8, 6:24 PM MDT | Special Weather Statement | GJT | 36 min |
| Jul 9, 1:31 PM MDT | Special Weather Statement | GJT | 44 min |
| Jul 9, 2:12 PM MDT | Special Weather Statement | GJT | 33 min |
| Jul 9, 2:21 PM MDT | Special Weather Statement | GJT | 39 min |
| Jul 11, 12:59 PM MDT | Special Weather Statement | GJT | 46 min |
| Jul 11, 1:31 PM MDT | Special Weather Statement | GJT | 29 min |
| Jul 11, 1:57 PM MDT | Special Weather Statement | GJT | 33 min |
| Jul 11, 2:03 PM MDT | Special Weather Statement | GJT | 42 min |
| Jul 11, 2:27 PM MDT | Special Weather Statement | GJT | 33 min |
| Jul 12, 9:58 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 15, 6:07 PM MDT | Special Weather Statement | GJT | 38 min |
| Jul 15, 6:28 PM MDT | Flash Flood Warning | GJT | 4 hr |
| Jul 15, 7:35 PM MDT | Special Weather Statement | GJT | 40 min |
| Jul 15, 8:02 PM MDT | Special Weather Statement | GJT | 43 min |
| Jul 15, 8:21 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 2, 4:52 AM MDT | Flash Flood Watch | GJT | 18 hr |
| Aug 2, 7:25 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 3, 3:45 PM MDT | Severe Thunderstorm Warning | SLC | 60 min |
| Aug 3, 5:41 PM MDT | Flash Flood Warning | GJT | 2 hr |
| Aug 5, 8:19 AM MDT | Red Flag Warning | SLC | 12 hr |
| Aug 11, 3:27 AM MDT | Flash Flood Watch | GJT | 21 hr |
| Aug 11, 5:33 PM MDT | Special Weather Statement | GJT | 57 min |
| Aug 11, 6:05 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 11, 6:42 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 26, 3:57 PM MDT | Special Weather Statement | GJT | 48 min |
| Aug 26, 5:01 PM MDT | Severe Thunderstorm Warning | GJT | 29 min |
| Oct 2, 2:01 PM MDT | Wind Advisory | GJT | 7 hr |
| Oct 5, 9:03 AM MDT | Flash Flood Watch | GJT | 15 hr |
| Oct 5, 1:08 PM MDT | Flash Flood Warning | GJT | 5 hr |
| Oct 5, 1:24 PM MDT | Areal Flood Warning | SLC | 9 hr |
| Oct 5, 4:20 PM MDT | Areal Flood Warning | GJT | 6 hr |
| Oct 5, 7:41 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Oct 7, 3:50 PM MDT | Special Weather Statement | GJT | 40 min |
| Oct 7, 4:24 PM MDT | Severe Thunderstorm Warning | GJT | 36 min |
| Oct 19, 3:36 AM MDT | Areal Flood Advisory | GJT | 3 hr |
| Oct 19, 3:46 AM MDT | Flash Flood Watch | GJT | 41 hr |
| Nov 2, 4:30 AM MST | Winter Storm Watch | GJT | 31 hr |
| Nov 3, 4:50 AM MST | Winter Storm Warning | GJT | 61 hr |
| Nov 3, 4:51 AM MST | Wind Advisory | GJT | 13 hr |
| Nov 4, 2:18 PM MST | Freeze Watch | GJT | 19 hr |
| Nov 5, 9:31 AM MST | Freeze Warning | GJT | 23 hr |
| Nov 9, 4:06 PM MST | Winter Weather Advisory | GJT | 44 hr |
| Nov 15, 1:04 AM MST | Winter Storm Warning | GJT | 55 hr |
| Nov 25, 2:36 PM MST | Wind Advisory | GJT | 5 hr |
| Dec 10, 3:26 PM MST | Winter Weather Advisory | GJT | 57 hr |
| Dec 13, 3:33 PM MST | Winter Weather Advisory | GJT | 53 hr |
| Dec 14, 1:40 PM MST | Winter Storm Warning | GJT | 43 hr |
| Dec 20, 5:00 AM MST | Winter Storm Watch | GJT | 32 hr |
| Dec 21, 5:14 AM MST | Winter Storm Warning | GJT | 63 hr |
| Dec 21, 1:24 PM MST | Winter Weather Advisory | GJT | 40 hr |
| Dec 23, 2:09 PM MST | Winter Storm Warning | GJT | 67 hr |
| Dec 23, 2:09 PM MST | Winter Weather Advisory | GJT | 67 hr |
| Dec 30, 1:26 PM MST | Winter Weather Advisory | GJT | 21 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 | 22 |
| Tornado Warning | 1 |
| Mesoscale Discussion | 3 |
| Special Weather Statement | 35 |
| Flooding | |
| Areal Flood Warning | 3 |
| Flash Flood Warning | 10 |
| Flash Flood Watch | 6 |
| Areal Flood Advisory | 17 |
| Winter | |
| Winter Storm Warning | 10 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 10 |
| Cold | |
| Freeze Warning | 5 |
| Freeze Watch | 4 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 1 |
| Wind Advisory | 4 |
| Fire | |
| Red Flag Warning | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 8 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20142016
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.