Alert archive / California / Mariposa County
Weather alerts in Mariposa County, California, 2020
33 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Mariposa County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 33
- Warnings
- 8
- Watches
- 2
- Advisories
- 4
- Busiest month
- April12 alerts
- Busiest day
- April 17, 20207 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Mariposa County, 2020
| 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 | 3 | 0 | 100% | 0 |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Hanford, CA: tornado warnings | 3 | 0 | 100% | 7 | 0% | |
| NWS Hanford, CA: severe thunderstorm warnings | 7 | 0 | 100% | 2 | 0% | |
| NWS Hanford, CA: flash flood warnings | 17 | 2 | 88% | 8 | 25% | 41 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 16, 11:23 AM PST | Mesoscale Discussion | SPC | 3 hr |
| Mar 11, 3:07 PM PDT | Special Weather Statement | HNX | 38 min |
| Mar 11, 4:16 PM PDT | Special Weather Statement | HNX | 44 min |
| Mar 11, 4:41 PM PDT | Areal Flood Advisory | HNX | 2 hr |
| Apr 5, 5:01 PM PDT | Special Weather Statement | HNX | 44 min |
| Apr 5, 6:53 PM PDT | Flash Flood Warning | HNX | 4 hr |
| Apr 5, 7:54 PM PDT | Areal Flood Advisory | HNX | 3 hr |
| Apr 5, 10:57 PM PDT | Areal Flood Advisory | HNX | 5 hr |
| Apr 17, 1:01 PM PDT | Special Weather Statement | HNX | 44 min |
| Apr 17, 1:27 PM PDT | Special Weather Statement | HNX | 48 min |
| Apr 17, 2:18 PM PDT | Special Weather Statement | HNX | 57 min |
| Apr 17, 2:47 PM PDT | Flash Flood Warning | HNX | 3 hr |
| Apr 17, 2:53 PM PDT | Special Weather Statement | HNX | 52 min |
| Apr 17, 3:04 PM PDT | Flash Flood Warning | HNX | 3 hr |
| Apr 17, 4:27 PM PDT | Special Weather Statement | HNX | 48 min |
| Apr 17, 5:40 PM PDT | Areal Flood Advisory | HNX | 2 hr |
| May 18, 7:29 PM PDT | Special Weather Statement | HNX | 31 min |
| Jun 12, 5:34 PM PDT | Special Weather Statement | HNX | 41 min |
| Jun 25, 5:33 PM PDT | Special Weather Statement | HNX | 42 min |
| Jul 16, 5:02 PM PDT | Severe Thunderstorm Warning | HNX | 28 min |
| Jul 19, 2:26 PM PDT | Special Weather Statement | HNX | 49 min |
| Jul 19, 3:18 PM PDT | Special Weather Statement | HNX | 57 min |
| Jul 20, 3:19 PM PDT | Special Weather Statement | HNX | 41 min |
| Jul 24, 3:02 PM PDT | Special Weather Statement | HNX | 43 min |
| Aug 10, 2:00 PM PDT | Special Weather Statement | HNX | 45 min |
| Aug 10, 5:25 PM PDT | Special Weather Statement | HNX | 35 min |
| Aug 17, 5:05 PM PDT | Severe Thunderstorm Warning | HNX | 55 min |
| Aug 17, 6:11 PM PDT | Severe Thunderstorm Warning | HNX | 34 min |
| Aug 24, 12:43 AM PDT | Special Weather Statement | HNX | 47 min |
| Sep 6, 1:00 PM PDT | Red Flag Warning | HNX | 3 days |
| Oct 22, 11:31 AM PDT | Fire Weather Watch | HNX | 51 hr |
| Oct 24, 2:04 PM PDT | Red Flag Warning | HNX | 3 days |
| Dec 10, 4:39 AM PST | Fire Weather Watch | HNX | 7 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 | 18 |
| Flooding | |
| Flash Flood Warning | 3 |
| Areal Flood Advisory | 4 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.