Alert archive / California / Alameda County
Weather alerts in Alameda County, California, 2014
31 weather alerts in 2014, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Alameda County and its neighbors
Each county as a circle sized by its count in 2014. Tap one for its archive.
- Alerts
- 31
- Warnings
- 4
- Watches
- 3
- Advisories
- 23
- Busiest month
- December20 alerts
- Busiest day
- December 11, 20147 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Alameda County, 2014
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 0 | 0 | ||||
| Flash flood warnings | 2 | 0 | 100% | 4 | 0% |
Each office's whole area, 2014
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS San Francisco Bay Area, CA: severe thunderstorm warnings | 3 | 0 | 100% | 6 | 0% | |
| NWS San Francisco Bay Area, CA: flash flood warnings | 20 | 6 | 70% | 39 | 18% | 52 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 |
|---|---|---|---|
| Feb 6, 9:39 AM PST | Areal Flood Advisory | MTR | 51 min |
| Feb 9, 1:17 AM PST | Areal Flood Advisory | MTR | 4 hr |
| Feb 11, 2:38 AM PST | Dense Fog Advisory | MTR | 7 hr |
| Feb 11, 2:57 PM PST | Dense Fog Advisory | MTR | 12 hr |
| Feb 28, 4:28 AM PST | Areal Flood Advisory | MTR | 4 hr |
| Mar 11, 10:37 AM PDT | Wind Advisory | MTR | 21 hr |
| Apr 1, 2:43 PM PDT | Mesoscale Discussion | SPC | 3 hr |
| May 11, 10:54 AM PDT | Excessive Heat Watch | MTR | 25 hr |
| May 12, 12:02 PM PDT | Heat Advisory | MTR | 56 hr |
| Oct 1, 8:40 AM PDT | Heat Advisory | MTR | 60 hr |
| Oct 3, 10:23 AM PDT | Heat Advisory | MTR | 35 hr |
| Dec 2, 7:39 AM PST | Areal Flood Advisory | MTR | 12 hr |
| Dec 2, 9:45 PM PST | Areal Flood Advisory | MTR | 6 hr |
| Dec 3, 4:05 AM PST | Areal Flood Advisory | MTR | 5 hr |
| Dec 3, 11:05 AM PST | Areal Flood Advisory | MTR | 115 min |
| Dec 8, 12:54 PM PST | Flash Flood Watch | MTR | 3 days |
| Dec 8, 1:02 PM PST | High Wind Watch | MTR | 25 hr |
| Dec 9, 2:02 PM PST | High Wind Warning | MTR | 50 hr |
| Dec 11, 6:50 AM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 11, 8:16 AM PST | Flash Flood Warning | MTR | 3 hr |
| Dec 11, 9:22 AM PST | Flash Flood Warning | MTR | 3 hr |
| Dec 11, 10:41 AM PST | Coastal Flood Warning | MTR | 8 hr |
| Dec 11, 11:22 AM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 11, 12:00 PM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 11, 2:59 PM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 11, 6:13 PM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 11, 9:16 PM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 12, 9:03 AM PST | Areal Flood Advisory | MTR | 18 hr |
| Dec 16, 5:36 PM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 19, 9:15 PM PST | Coastal Flood Advisory | MTR | 4 days |
| Dec 29, 3:43 AM PST | Wind Advisory | MTR | 56 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 | |
| Mesoscale Discussion | 1 |
| Flooding | |
| Flash Flood Warning | 2 |
| Flash Flood Watch | 1 |
| Areal Flood Advisory | 15 |
| Heat | |
| Excessive Heat Watch | 1 |
| Heat Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 1 |
| Wind Advisory | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
| Coast and beach | |
| Coastal Flood Warning | 1 |
| Coastal Flood Advisory | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20132015
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.