Alert archive / California / Riverside County
Weather alerts in Riverside County, California, 2009
108 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Riverside County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 108
- Warnings
- 35
- Watches
- 27
- Advisories
- 46
- Busiest month
- December19 alerts
- Busiest day
- October 27, 20096 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Riverside County, 2009
| 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 | 2 | 0 | 100% | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS San Diego, CA: severe thunderstorm warnings | 9 | 1 | 89% | 2 | 50% | 46 min |
| NWS San Diego, CA: flash flood warnings | 7 | 3 | 57% | 9 | 44% | 40 min |
| NWS Phoenix, AZ: severe thunderstorm warnings | 54 | 12 | 78% | 37 | 57% | 17 min |
| NWS Phoenix, AZ: flash flood warnings | 16 | 3 | 81% | 6 | 67% | 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, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 1, 3:57 PM PST | Dense Fog Advisory | SGX | 18 hr |
| Jan 7, 1:01 PM PST | High Wind Watch | SGX | 24 hr |
| Jan 8, 1:08 PM PST | High Wind Warning | SGX | 5 days |
| Jan 8, 1:08 PM PST | Wind Advisory | SGX | 5 days |
| Jan 27, 7:11 AM PST | Wind Advisory | SGX | 8 hr |
| Jan 28, 1:13 PM PST | High Wind Watch | SGX | 6 hr |
| Jan 28, 1:13 PM PST | Wind Advisory | SGX | 52 hr |
| Jan 28, 7:38 PM PST | High Wind Warning | SGX | 42 hr |
| Feb 5, 6:53 AM PST | Wind Advisory | SGX | 18 hr |
| Feb 5, 8:24 PM PST | Areal Flood Advisory | SGX | 3 hr |
| Feb 6, 1:09 PM PST | Winter Weather Advisory | SGX | 37 hr |
| Feb 6, 1:37 PM PST | Flash Flood Watch | SGX | 26 hr |
| Feb 8, 8:06 PM PST | Winter Weather Advisory | SGX | 28 hr |
| Feb 8, 8:10 PM PST | Wind Advisory | SGX | 28 hr |
| Feb 10, 1:15 PM PST | Frost Advisory | SGX | 20 hr |
| Feb 13, 1:56 AM PST | Winter Weather Advisory | SGX | 19 hr |
| Feb 14, 1:46 PM PST | Winter Storm Watch | SGX | 25 hr |
| Feb 15, 1:30 PM PST | Wind Advisory | SGX | 26 hr |
| Feb 15, 1:31 PM PST | Flash Flood Watch | SGX | 28 hr |
| Feb 15, 1:31 PM PST | Winter Storm Warning | SGX | 34 hr |
| Feb 16, 10:18 AM PST | Areal Flood Advisory | SGX | 8 hr |
| Mar 21, 3:00 AM PDT | High Wind Watch | SGX | 15 hr |
| Mar 21, 5:59 PM PDT | High Wind Warning | SGX | 33 hr |
| Mar 21, 5:59 PM PDT | Wind Advisory | SGX | 33 hr |
| Mar 25, 3:04 AM PDT | Fire Weather Watch | PSR | 11 hr |
| Mar 25, 2:00 PM PDT | Red Flag Warning | PSR | 33 hr |
| Mar 26, 1:11 PM PDT | High Wind Warning | SGX | 24 hr |
| Mar 26, 1:11 PM PDT | Wind Advisory | SGX | 24 hr |
| Mar 28, 3:26 PM PDT | Fire Weather Watch | PSR | 23 hr |
| Mar 28, 3:26 PM PDT | Red Flag Warning | PSR | 29 hr |
| Mar 29, 8:51 AM PDT | Wind Advisory | SGX | 15 hr |
| Mar 29, 2:23 PM PDT | Red Flag Warning | PSR | 25 hr |
| Apr 2, 4:01 AM PDT | High Wind Watch | SGX | 24 hr |
| Apr 2, 4:10 AM PDT | Fire Weather Watch | PSR | 11 hr |
| Apr 2, 2:55 PM PDT | Red Flag Warning | PSR | 31 hr |
| Apr 3, 3:34 AM PDT | High Wind Warning | SGX | 18 hr |
| Apr 3, 6:46 AM PDT | Dense Fog Advisory | SGX | 4 hr |
| Apr 8, 2:53 AM PDT | Wind Advisory | SGX | 19 hr |
| Apr 13, 1:24 PM PDT | High Wind Watch | SGX | 14 hr |
| Apr 13, 3:49 PM PDT | Fire Weather Watch | PSR | 13 hr |
| Apr 14, 3:06 AM PDT | High Wind Warning | SGX | 32 hr |
| Apr 14, 3:06 AM PDT | Wind Advisory | SGX | 22 hr |
| Apr 14, 5:10 AM PDT | Red Flag Warning | PSR | 15 hr |
| Apr 15, 1:05 AM PDT | Wind Advisory | SGX | 19 hr |
| Apr 24, 5:43 AM PDT | Fire Weather Watch | PSR | 8 hr |
| Apr 24, 1:51 PM PDT | Red Flag Warning | PSR | 15 hr |
| Apr 24, 7:54 PM PDT | Wind Advisory | SGX | 18 hr |
| May 1, 11:53 AM PDT | Wind Advisory | SGX | 32 hr |
| Jun 10, 1:26 PM PDT | Dense Fog Advisory | SGX | 22 hr |
| Jun 13, 12:02 AM PDT | Dense Fog Advisory | SGX | 10 hr |
| Jul 18, 7:17 PM PDT | Blowing Dust Advisory | SGX | 2 hr |
| Jul 23, 1:27 PM PDT | Flash Flood Watch | SGX | 31 hr |
| Jul 24, 3:03 PM PDT | Severe Thunderstorm Warning | PSR | 42 min |
| Jul 24, 4:00 PM PDT | Areal Flood Advisory | PSR | 2 hr |
| Aug 5, 2:50 PM PDT | Fire Weather Watch | PSR | 29 hr |
| Aug 6, 8:51 AM PDT | Red Flag Warning | SGX | 12 hr |
| Aug 21, 1:33 PM PDT | Flash Flood Watch | SGX | 30 hr |
| Sep 2, 2:11 PM PDT | Flash Flood Warning | SGX | 49 min |
| Sep 2, 3:24 PM PDT | Flash Flood Warning | SGX | 51 min |
| Sep 2, 4:19 PM PDT | Severe Thunderstorm Warning | SGX | 26 min |
| Sep 2, 6:13 PM PDT | Severe Thunderstorm Warning | PSR | 22 min |
| Sep 5, 7:14 PM PDT | Areal Flood Advisory | PSR | 106 min |
| Sep 20, 1:39 PM PDT | Fire Weather Watch | SGX | 24 hr |
| Sep 21, 1:36 PM PDT | Red Flag Warning | SGX | 3 days |
| Sep 29, 3:17 AM PDT | Wind Advisory | SGX | 24 hr |
| Sep 29, 1:42 PM PDT | Fire Weather Watch | SGX | 24 hr |
| Sep 30, 1:29 PM PDT | Red Flag Warning | SGX | 29 hr |
| Oct 1, 3:00 AM PDT | Wind Advisory | SGX | 9 hr |
| Oct 3, 1:41 PM PDT | High Wind Warning | SGX | 26 hr |
| Oct 3, 1:41 PM PDT | Wind Advisory | SGX | 30 hr |
| Oct 25, 1:25 PM PDT | Red Flag Warning | PSR | 6 hr |
| Oct 26, 12:50 AM PDT | Fire Weather Watch | PSR | 13 hr |
| Oct 26, 2:15 PM PDT | Red Flag Warning | PSR | 30 hr |
| Oct 26, 8:23 PM PDT | High Wind Warning | SGX | 26 hr |
| Oct 27, 2:36 AM PDT | Fire Weather Watch | PSR | 11 hr |
| Oct 27, 2:59 AM PDT | Wind Advisory | SGX | 37 hr |
| Oct 27, 9:56 AM PDT | Fire Weather Watch | SGX | 17 hr |
| Oct 27, 9:56 AM PDT | Red Flag Warning | SGX | 30 hr |
| Oct 27, 1:51 PM PDT | Red Flag Warning | PSR | 27 hr |
| Nov 5, 4:39 AM PST | Dense Fog Advisory | SGX | 3 hr |
| Nov 13, 2:18 PM PST | Fire Weather Watch | SGX | 23 hr |
| Nov 14, 1:36 PM PST | Red Flag Warning | SGX | 26 hr |
| Nov 14, 1:50 PM PST | Wind Advisory | SGX | 28 hr |
| Nov 15, 5:40 AM PST | Red Flag Warning | PSR | 6 hr |
| Nov 23, 9:31 PM PST | Wind Advisory | SGX | 25 min |
| Nov 23, 9:56 PM PST | High Wind Warning | SGX | 5 hr |
| Nov 24, 3:03 AM PST | Wind Advisory | SGX | 9 hr |
| Nov 24, 10:01 AM PST | Red Flag Warning | SGX | 48 hr |
| Nov 28, 1:26 PM PST | Wind Advisory | SGX | 48 hr |
| Dec 5, 1:05 PM PST | Winter Storm Watch | SGX | 23 hr |
| Dec 6, 11:16 AM PST | High Wind Watch | SGX | 16 hr |
| Dec 6, 12:27 PM PST | Winter Storm Warning | SGX | 39 hr |
| Dec 6, 7:09 PM PST | Flash Flood Watch | SGX | 25 hr |
| Dec 7, 2:54 AM PST | High Wind Warning | SGX | 27 hr |
| Dec 7, 7:57 AM PST | Wind Advisory | SGX | 19 hr |
| Dec 8, 1:14 PM PST | Frost Advisory | SGX | 20 hr |
| Dec 12, 3:23 AM PST | Wind Advisory | SGX | 31 hr |
| Dec 12, 4:57 PM PST | Areal Flood Advisory | SGX | 9 hr |
| Dec 12, 5:59 PM PST | Flash Flood Watch | SGX | 15 hr |
| Dec 13, 5:49 AM PST | Areal Flood Advisory | SGX | 3 hr |
| Dec 21, 3:48 AM PST | High Wind Watch | SGX | 23 hr |
| Dec 22, 2:56 AM PST | High Wind Warning | SGX | 10 hr |
| Dec 22, 2:56 AM PST | Wind Advisory | SGX | 10 hr |
| Dec 22, 1:14 PM PST | Wind Advisory | SGX | 8 hr |
| Dec 22, 4:36 PM PST | High Wind Warning | SGX | 4 hr |
| Dec 22, 9:13 PM PST | Wind Advisory | SGX | 13 hr |
| Dec 23, 1:45 AM PST | Frost Advisory | SGX | 7 hr |
| Dec 23, 1:45 AM PST | Frost Advisory | SGX | 31 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 |
| Flooding | |
| Flash Flood Warning | 2 |
| Flash Flood Watch | 6 |
| Areal Flood Advisory | 6 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 3 |
| Cold | |
| Frost Advisory | 4 |
| Wind and dust | |
| High Wind Warning | 12 |
| High Wind Watch | 7 |
| Blowing Dust Advisory | 1 |
| Wind Advisory | 27 |
| Fire | |
| Red Flag Warning | 16 |
| Fire Weather Watch | 12 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20082010
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.