Alert archive / California / Ventura County
Weather alerts in Ventura County, California, 2021
10 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Ventura County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 10
- Warnings
- 0
- Watches
- 0
- Advisories
- 9
- Busiest month
- December7 alerts
- Busiest day
- December 30, 20213 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Ventura County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 0 | 1 | 0% | |||
| Flash flood warnings | 0 | 1 | 0% |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS San Francisco Bay Area, CA: flash flood warnings | 16 | 2 | 88% | 30 | 7% | 354 min |
| NWS Sacramento, CA: tornado warnings | 2 | 1 | 50% | 4 | 25% | 2 min |
| NWS Sacramento, CA: severe thunderstorm warnings | 1 | 0 | 100% | 0 | ||
| NWS Sacramento, CA: flash flood warnings | 3 | 1 | 67% | 8 | 13% | 96 min |
| NWS Los Angeles, CA: tornado warnings | 0 | 2 | 0% | |||
| NWS Los Angeles, CA: severe thunderstorm warnings | 0 | 4 | 0% | |||
| NWS Los Angeles, CA: flash flood warnings | 5 | 0 | 100% | 9 | 0% | |
| NWS Medford, OR: severe thunderstorm warnings | 2 | 0 | 100% | 0 | ||
| NWS Medford, OR: flash flood warnings | 3 | 1 | 67% | 3 | 33% | 3 min |
| NWS Hanford, CA: tornado warnings | 1 | 0 | 100% | 0 | ||
| NWS Hanford, CA: severe thunderstorm warnings | 5 | 0 | 100% | 6 | 0% | |
| NWS Hanford, CA: flash flood warnings | 17 | 1 | 94% | 20 | 10% | 298 min |
| NWS San Diego, CA: severe thunderstorm warnings | 15 | 4 | 73% | 19 | 32% | 17 min |
| NWS San Diego, CA: flash flood warnings | 24 | 7 | 71% | 76 | 28% | 67 min |
| NWS Phoenix, AZ: severe thunderstorm warnings | 128 | 54 | 58% | 151 | 83% | 21 min |
| NWS Phoenix, AZ: flash flood warnings | 255 | 102 | 60% | 196 | 85% | 87 min |
| NWS Las Vegas, NV: tornado warnings | 0 | 2 | 0% | |||
| NWS Las Vegas, NV: severe thunderstorm warnings | 77 | 27 | 65% | 113 | 57% | 22 min |
| NWS Las Vegas, NV: flash flood warnings | 130 | 42 | 68% | 118 | 73% | 82 min |
| NWS Eureka, CA: severe thunderstorm warnings | 0 | 2 | 0% | |||
| NWS Eureka, CA: flash flood warnings | 2 | 0 | 100% | 1 | 0% | |
| NWS Reno, NV: tornado warnings | 0 | 1 | 0% | |||
| NWS Reno, NV: severe thunderstorm warnings | 9 | 0 | 100% | 6 | 0% | |
| NWS Reno, NV: flash flood warnings | 13 | 4 | 69% | 20 | 35% | 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, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 28, 4:42 PM PST | Areal Flood Advisory | LOX | 6 hr |
| Mar 12, 6:28 PM PST | Special Weather Statement | LOX | 47 min |
| Oct 25, 10:09 AM PDT | Areal Flood Advisory | LOX | 4 hr |
| Dec 14, 1:19 AM PST | Areal Flood Advisory | LOX | 6 hr |
| Dec 14, 10:05 AM PST | Areal Flood Advisory | LOX | 4 hr |
| Dec 23, 5:43 PM PST | Areal Flood Advisory | LOX | 3 hr |
| Dec 25, 9:41 PM PST | Areal Flood Advisory | LOX | 2 hr |
| Dec 29, 11:02 PM PST | Areal Flood Advisory | LOX | 6 hr |
| Dec 30, 4:54 AM PST | Areal Flood Advisory | LOX | 6 hr |
| Dec 30, 10:47 AM PST | Areal Flood Advisory | LOX | 4 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 | |
| Special Weather Statement | 1 |
| Flooding | |
| Areal Flood Advisory | 9 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.