Alert archive / Utah / San Juan County
Weather alerts in San Juan County, Utah, 2010
129 weather alerts in 2010, 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 2010. Tap one for its archive.
- Alerts
- 129
- Warnings
- 49
- Watches
- 33
- Advisories
- 41
- Busiest month
- August21 alerts
- Busiest day
- October 6, 201013 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 1 tornado warnings covering San Juan County in 2010 had a tornado report inside them.
San Juan County, 2010
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 15 | 3 | 80% | 3 | 67% | 19 min |
| Flash flood warnings | 8 | 2 | 75% | 3 | 33% | 68 min |
Each office's whole area, 2010
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Grand Junction, CO: tornado warnings | 1 | 0 | 100% | 0 | ||
| NWS Grand Junction, CO: severe thunderstorm warnings | 49 | 8 | 84% | 38 | 24% | 21 min |
| NWS Grand Junction, CO: flash flood warnings | 20 | 3 | 85% | 10 | 40% | 60 min |
| NWS Salt Lake City, UT: tornado warnings | 1 | 0 | 100% | 2 | 0% | |
| NWS Salt Lake City, UT: severe thunderstorm warnings | 101 | 15 | 85% | 73 | 41% | 23 min |
| NWS Salt Lake City, UT: flash flood warnings | 70 | 22 | 69% | 41 | 54% | 45 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 16, 3:24 PM MST | Winter Storm Watch | GJT | 24 hr |
| Jan 17, 3:29 PM MST | Winter Storm Warning | GJT | 48 hr |
| Jan 17, 3:29 PM MST | Winter Weather Advisory | GJT | 48 hr |
| Jan 19, 3:30 PM MST | Winter Weather Advisory | GJT | 27 hr |
| Jan 19, 10:05 PM MST | Winter Storm Warning | GJT | 18 hr |
| Jan 20, 3:31 AM MST | Blizzard Watch | GJT | 13 hr |
| Jan 20, 4:09 PM MST | Blizzard Warning | GJT | 42 hr |
| Jan 20, 4:09 PM MST | Winter Storm Watch | GJT | 12 hr |
| Jan 20, 4:09 PM MST | Winter Storm Warning | GJT | 5 days |
| Jan 21, 10:58 AM MST | Flash Flood Watch | GJT | 13 hr |
| Jan 21, 4:15 PM MST | Flash Flood Warning | SLC | 6 hr |
| Jan 21, 7:24 PM MST | Flash Flood Warning | GJT | 4 hr |
| Jan 21, 10:17 PM MST | Areal Flood Warning | SLC | 8 hr |
| Jan 21, 11:57 PM MST | Areal Flood Warning | GJT | 10 hr |
| Jan 26, 3:55 PM MST | Winter Storm Watch | GJT | 8 hr |
| Jan 26, 3:55 PM MST | Winter Storm Warning | GJT | 44 hr |
| Jan 26, 3:55 PM MST | Winter Weather Advisory | GJT | 44 hr |
| Jan 28, 3:06 PM MST | Dense Fog Advisory | GJT | 22 hr |
| Feb 5, 2:43 PM MST | Winter Storm Watch | GJT | 13 hr |
| Feb 6, 3:43 AM MST | Winter Storm Warning | GJT | 54 hr |
| Feb 18, 4:06 AM MST | Winter Weather Advisory | GJT | 4 days |
| Feb 18, 9:27 PM MST | Winter Storm Warning | GJT | 4 days |
| Feb 18, 9:36 PM MST | Dense Fog Advisory | GJT | 13 hr |
| Mar 3, 3:18 PM MST | Winter Weather Advisory | GJT | 63 hr |
| Mar 6, 4:47 AM MST | Winter Storm Warning | GJT | 61 hr |
| Mar 9, 3:27 AM MST | Winter Weather Advisory | GJT | 45 hr |
| Mar 13, 3:36 AM MST | Winter Storm Warning | GJT | 37 hr |
| Mar 13, 3:36 AM MST | Winter Weather Advisory | GJT | 43 hr |
| Mar 15, 3:32 AM MDT | Dense Fog Advisory | GJT | 7 hr |
| Mar 29, 3:54 PM MDT | Wind Advisory | GJT | 28 hr |
| Mar 30, 8:00 PM MDT | Wind Advisory | GJT | 25 hr |
| Mar 31, 4:16 AM MDT | Winter Weather Advisory | GJT | 48 hr |
| Apr 4, 4:38 AM MDT | Wind Advisory | GJT | 46 hr |
| Apr 11, 3:16 PM MDT | Wind Advisory | GJT | 33 hr |
| Apr 20, 3:09 PM MDT | Wind Advisory | GJT | 27 hr |
| Apr 26, 3:07 PM MDT | High Wind Watch | GJT | 23 hr |
| Apr 27, 2:21 PM MDT | High Wind Warning | GJT | 34 hr |
| Apr 28, 2:56 PM MDT | Freeze Watch | GJT | 14 hr |
| Apr 29, 4:38 AM MDT | Freeze Warning | GJT | 28 hr |
| Apr 29, 3:04 PM MDT | Freeze Watch | GJT | 21 hr |
| Apr 30, 12:27 PM MDT | Freeze Warning | GJT | 21 hr |
| May 1, 2:31 PM MDT | Winter Weather Advisory | GJT | 38 hr |
| May 2, 2:29 PM MDT | Freeze Warning | GJT | 18 hr |
| May 11, 4:41 AM MDT | Wind Advisory | GJT | 15 hr |
| May 20, 3:03 PM MDT | High Wind Watch | GJT | 13 hr |
| May 20, 3:03 PM MDT | Wind Advisory | GJT | 30 hr |
| May 21, 4:21 AM MDT | High Wind Warning | GJT | 41 hr |
| May 22, 3:32 PM MDT | Wind Advisory | GJT | 32 hr |
| May 27, 8:09 PM MDT | Wind Advisory | GJT | 25 hr |
| Jun 16, 3:05 AM MDT | Wind Advisory | GJT | 18 hr |
| Jul 21, 9:29 AM MDT | Flash Flood Watch | GJT | 12 hr |
| Jul 21, 2:02 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Jul 21, 2:47 PM MDT | Severe Thunderstorm Warning | GJT | 43 min |
| Jul 21, 3:32 PM MDT | Severe Thunderstorm Warning | GJT | 26 min |
| Jul 22, 5:58 AM MDT | Flash Flood Watch | GJT | 15 hr |
| Jul 22, 5:43 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 27, 3:00 AM MDT | Flash Flood Watch | GJT | 18 hr |
| Jul 27, 5:08 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 28, 4:11 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Jul 28, 1:40 PM MDT | Flash Flood Watch | GJT | 31 hr |
| Jul 28, 2:21 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 28, 3:29 PM MDT | Flash Flood Warning | GJT | 84 min |
| Jul 30, 3:41 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Jul 30, 3:02 PM MDT | Flash Flood Watch | GJT | 30 hr |
| Jul 31, 1:39 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Jul 31, 3:03 PM MDT | Flash Flood Watch | GJT | 3 days |
| Aug 2, 1:58 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 3, 2:08 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 3, 6:18 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 4, 3:16 AM MDT | Flash Flood Watch | GJT | 18 hr |
| Aug 4, 12:54 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 4, 7:07 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 4, 8:33 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 4, 9:43 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 5, 4:38 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Aug 11, 4:35 PM MDT | Severe Thunderstorm Warning | GJT | 40 min |
| Aug 19, 4:29 AM MDT | Flash Flood Watch | GJT | 17 hr |
| Aug 19, 1:37 PM MDT | Severe Thunderstorm Warning | GJT | 23 min |
| Aug 19, 1:50 PM MDT | Flash Flood Warning | GJT | 3 hr |
| Aug 19, 1:59 PM MDT | Severe Thunderstorm Warning | GJT | 46 min |
| Aug 19, 3:27 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Aug 19, 3:40 PM MDT | Special Weather Statement | SLC | 35 min |
| Aug 19, 3:59 PM MDT | Severe Thunderstorm Warning | SLC | 46 min |
| Aug 19, 4:52 PM MDT | Severe Thunderstorm Warning | SLC | 24 min |
| Aug 22, 4:47 AM MDT | Flash Flood Watch | GJT | 16 hr |
| Aug 29, 4:33 AM MDT | Wind Advisory | GJT | 16 hr |
| Aug 29, 1:13 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 8, 3:30 PM MDT | Flash Flood Warning | GJT | 87 min |
| Sep 21, 2:34 PM MDT | Flash Flood Watch | GJT | 37 hr |
| Sep 22, 7:25 PM MDT | Severe Thunderstorm Warning | SLC | 35 min |
| Sep 22, 8:16 PM MDT | Areal Flood Advisory | GJT | 3 hr |
| Oct 5, 10:07 AM MDT | Areal Flood Warning | SLC | 24 hr |
| Oct 5, 3:25 PM MDT | Flash Flood Watch | GJT | 29 hr |
| Oct 6, 9:18 AM MDT | Severe Thunderstorm Warning | SLC | 42 min |
| Oct 6, 9:38 AM MDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 6, 9:54 AM MDT | Areal Flood Warning | SLC | 23 hr |
| Oct 6, 10:29 AM MDT | Tornado Watch | SPC | 7 hr |
| Oct 6, 11:12 AM MDT | Severe Thunderstorm Warning | SLC | 48 min |
| Oct 6, 11:25 AM MDT | Tornado Warning | SLC | 20 min |
| Oct 6, 12:02 PM MDT | Severe Thunderstorm Warning | SLC | 43 min |
| Oct 6, 12:08 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 6, 12:45 PM MDT | Severe Thunderstorm Warning | SLC | 60 min |
| Oct 6, 2:41 PM MDT | Severe Thunderstorm Warning | GJT | 49 min |
| Oct 6, 3:12 PM MDT | Severe Thunderstorm Warning | GJT | 48 min |
| Oct 6, 3:15 PM MDT | Severe Thunderstorm Warning | GJT | 45 min |
| Oct 6, 3:43 PM MDT | Mesoscale Discussion | SPC | 92 min |
| Oct 7, 1:18 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Oct 7, 1:53 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Oct 21, 2:43 AM MDT | Flash Flood Watch | GJT | 15 hr |
| Oct 23, 6:09 AM MDT | Winter Storm Watch | GJT | 32 hr |
| Oct 23, 3:16 PM MDT | Winter Storm Warning | GJT | 69 hr |
| Oct 24, 2:34 PM MDT | Freeze Warning | GJT | 42 hr |
| Nov 7, 3:21 PM MST | Winter Weather Advisory | GJT | 54 hr |
| Nov 10, 3:34 AM MST | Winter Weather Advisory | GJT | 44 hr |
| Nov 19, 3:08 PM MST | Winter Storm Watch | GJT | 3 hr |
| Nov 19, 5:56 PM MST | Winter Storm Warning | GJT | 3 days |
| Nov 20, 8:50 AM MST | Wind Advisory | GJT | 9 hr |
| Nov 21, 10:09 AM MST | Wind Advisory | GJT | 10 hr |
| Nov 22, 4:29 AM MST | Blizzard Watch | GJT | 23 hr |
| Nov 22, 3:10 PM MST | High Wind Watch | GJT | 13 hr |
| Nov 22, 3:13 PM MST | Blizzard Warning | GJT | 54 hr |
| Nov 23, 3:41 AM MST | High Wind Warning | GJT | 25 hr |
| Nov 27, 3:59 AM MST | Winter Weather Advisory | GJT | 63 hr |
| Dec 14, 2:30 PM MST | Winter Weather Advisory | GJT | 52 hr |
| Dec 17, 4:06 AM MST | Winter Weather Advisory | GJT | 3 days |
| Dec 18, 4:04 AM MST | Winter Storm Warning | GJT | 6 days |
| Dec 21, 2:45 PM MST | Winter Storm Watch | GJT | 24 hr |
| Dec 27, 3:13 PM MST | Winter Storm Watch | GJT | 24 hr |
| Dec 28, 3:26 PM MST | Winter Storm Warning | GJT | 67 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 | 15 |
| Tornado Warning | 1 |
| Severe Thunderstorm Watch | 1 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 5 |
| Special Weather Statement | 1 |
| Flooding | |
| Areal Flood Warning | 4 |
| Flash Flood Warning | 8 |
| Flash Flood Watch | 16 |
| Areal Flood Advisory | 11 |
| Winter | |
| Blizzard Warning | 2 |
| Winter Storm Warning | 12 |
| Blizzard Watch | 2 |
| Winter Storm Watch | 8 |
| Winter Weather Advisory | 14 |
| Cold | |
| Freeze Warning | 4 |
| Freeze Watch | 2 |
| Wind and dust | |
| High Wind Warning | 3 |
| High Wind Watch | 3 |
| Wind Advisory | 13 |
| Fog and smoke | |
| Dense Fog Advisory | 3 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20092011
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.