Alert archive / California / Alameda County
Weather alerts in Alameda County, California, 2025
109 weather alerts in 2025, 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 2025. Tap one for its archive.
- Alerts
- 109
- Warnings
- 7
- Watches
- 7
- Advisories
- 89
- Busiest month
- December27 alerts
- Busiest day
- December 25, 20255 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, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 2 | 2 | 0% | 3 | 0% | |
| Flash flood warnings | 1 | 1 | 0% | 7 | 14% | 59 min |
Each office's whole area, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS San Francisco Bay Area, CA: tornado warnings | 2 | 0 | 100% | 0 | ||
| NWS San Francisco Bay Area, CA: severe thunderstorm warnings | 28 | 9 | 68% | 39 | 36% | 12 min |
| NWS San Francisco Bay Area, CA: flash flood warnings | 8 | 5 | 38% | 89 | 12% | 172 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 6, 7:17 AM PST | Wind Advisory | MTR | 51 hr |
| Jan 6, 9:54 AM PST | Dense Fog Advisory | MTR | 2 hr |
| Jan 10, 12:07 AM PST | Wind Advisory | MTR | 57 hr |
| Jan 10, 10:43 AM PST | Coastal Flood Advisory | MTR | 25 hr |
| Jan 11, 11:34 AM PST | Coastal Flood Advisory | MTR | 24 hr |
| Jan 12, 11:18 AM PST | Frost Advisory | MTR | 22 hr |
| Jan 12, 11:36 AM PST | Coastal Flood Advisory | MTR | 25 hr |
| Jan 13, 1:00 PM PST | Frost Advisory | MTR | 20 hr |
| Jan 15, 2:56 PM PST | Frost Advisory | MTR | 18 hr |
| Jan 16, 9:02 AM PST | Frost Advisory | MTR | 24 hr |
| Jan 19, 2:02 AM PST | Wind Advisory | MTR | 41 hr |
| Jan 19, 1:31 PM PST | Frost Advisory | MTR | 19 hr |
| Jan 20, 11:29 AM PST | Frost Advisory | MTR | 22 hr |
| Jan 21, 11:26 AM PST | Frost Advisory | MTR | 23 hr |
| Jan 22, 1:44 PM PST | Frost Advisory | MTR | 19 hr |
| Jan 24, 11:07 AM PST | Frost Advisory | MTR | 22 hr |
| Jan 24, 11:07 AM PST | Freeze Watch | MTR | 5 days |
| Jan 25, 10:39 AM PST | Frost Advisory | MTR | 22 hr |
| Jan 26, 10:45 AM PST | Frost Advisory | MTR | 22 hr |
| Jan 27, 11:57 AM PST | Frost Advisory | MTR | 21 hr |
| Jan 30, 9:17 PM PST | Flood Watch | MTR | 65 hr |
| Feb 3, 12:44 AM PST | Flood Watch | MTR | 43 hr |
| Feb 3, 8:46 AM PST | Wind Advisory | MTR | 36 hr |
| Feb 3, 10:59 PM PST | Areal Flood Advisory | MTR | 8 hr |
| Feb 4, 7:13 AM PST | Areal Flood Advisory | MTR | 3 hr |
| Feb 5, 9:57 AM PST | Frost Advisory | MTR | 19 hr |
| Feb 6, 4:32 AM PST | Wind Advisory | MTR | 20 hr |
| Feb 7, 12:25 AM PST | Frost Advisory | MTR | 33 hr |
| Feb 7, 11:21 PM PST | Frost Advisory | MTR | 34 hr |
| Feb 7, 11:21 PM PST | Freeze Warning | MTR | 34 hr |
| Feb 8, 11:25 PM PST | Frost Advisory | MTR | 34 hr |
| Feb 8, 11:25 PM PST | Freeze Warning | MTR | 34 hr |
| Feb 9, 11:49 PM PST | Frost Advisory | MTR | 33 hr |
| Feb 11, 9:35 AM PST | Flood Watch | MTR | 63 hr |
| Feb 11, 12:08 PM PST | High Wind Watch | MTR | 23 hr |
| Feb 12, 10:51 AM PST | Wind Advisory | MTR | 41 hr |
| Feb 13, 12:32 AM PST | Areal Flood Advisory | MTR | 9 hr |
| Feb 13, 1:51 AM PST | Areal Flood Advisory | MTR | 18 hr |
| Feb 13, 7:53 AM PST | Areal Flood Warning | MTR | 14 hr |
| Feb 13, 11:31 AM PST | Areal Flood Advisory | MTR | 6 hr |
| Feb 25, 4:33 AM PST | Dense Fog Advisory | MTR | 5 hr |
| Mar 6, 11:32 AM PST | Frost Advisory | MTR | 21 hr |
| Mar 12, 12:10 AM PDT | Wind Advisory | MTR | 20 hr |
| Mar 12, 3:08 PM PDT | Special Weather Statement | MTR | 37 min |
| Mar 14, 12:17 AM PDT | Wind Advisory | MTR | 8 hr |
| Mar 14, 5:28 AM PDT | Areal Flood Advisory | MTR | 3 hr |
| Mar 15, 12:59 AM PDT | Wind Advisory | MTR | 49 hr |
| Mar 17, 12:22 PM PDT | Special Weather Statement | MTR | 23 min |
| May 3, 12:20 PM PDT | Wind Advisory | MTR | 50 hr |
| May 26, 4:30 PM PDT | Coastal Flood Advisory | MTR | 9 hr |
| May 27, 2:26 AM PDT | Coastal Flood Advisory | MTR | 24 hr |
| May 27, 12:07 PM PDT | Heat Advisory | MTR | 3 days |
| May 30, 12:31 PM PDT | Heat Advisory | MTR | 31 hr |
| Jun 21, 8:47 PM PDT | Coastal Flood Advisory | MTR | 27 hr |
| Jun 22, 11:54 PM PDT | Coastal Flood Advisory | MTR | 25 hr |
| Jun 24, 1:10 AM PDT | Coastal Flood Advisory | MTR | 24 hr |
| Jun 25, 2:10 AM PDT | Coastal Flood Advisory | MTR | 24 hr |
| Jun 26, 2:11 AM PDT | Coastal Flood Advisory | MTR | 24 hr |
| Jul 21, 2:06 AM PDT | Coastal Flood Advisory | MTR | 22 hr |
| Jul 21, 11:35 PM PDT | Coastal Flood Advisory | MTR | 25 hr |
| Jul 23, 12:57 AM PDT | Coastal Flood Advisory | MTR | 25 hr |
| Jul 24, 1:38 AM PDT | Coastal Flood Advisory | MTR | 24 hr |
| Jul 29, 4:35 PM PDT | Tsunami Advisory | AAQ | 39 hr |
| Aug 19, 12:27 PM PDT | Heat Advisory | MTR | 4 days |
| Sep 22, 8:04 PM PDT | Heat Advisory | MTR | 23 hr |
| Oct 13, 3:39 PM PDT | Areal Flood Advisory | MTR | 3 hr |
| Oct 13, 4:33 PM PDT | Areal Flood Advisory | MTR | 5 hr |
| Oct 13, 4:53 PM PDT | Areal Flood Advisory | MTR | 6 hr |
| Oct 13, 5:22 PM PDT | Areal Flood Advisory | MTR | 5 hr |
| Oct 13, 6:52 PM PDT | Areal Flood Advisory | MTR | 3 hr |
| Oct 13, 7:05 PM PDT | Areal Flood Advisory | MTR | 3 hr |
| Nov 2, 10:40 PM PST | Coastal Flood Advisory | MTR | 6 days |
| Nov 2, 11:59 PM PST | Wind Advisory | MTR | 64 hr |
| Nov 11, 11:24 AM PST | Wind Advisory | MTR | 53 hr |
| Nov 13, 7:00 AM PST | Areal Flood Advisory | MTR | 8 hr |
| Nov 16, 11:54 PM PST | Areal Flood Advisory | MTR | 4 hr |
| Nov 17, 12:38 AM PST | Special Weather Statement | MTR | 37 min |
| Nov 17, 12:43 AM PST | Areal Flood Advisory | MTR | 3 hr |
| Nov 22, 4:50 AM PST | Dense Fog Advisory | MTR | 6 hr |
| Nov 24, 10:03 PM PST | Dense Fog Advisory | MTR | 13 hr |
| Nov 25, 9:47 PM PST | Dense Fog Advisory | MTR | 10 hr |
| Nov 26, 9:04 PM PST | Dense Fog Advisory | MTR | 10 hr |
| Nov 30, 6:54 PM PST | Coastal Flood Advisory | MTR | 7 days |
| Dec 3, 5:46 PM PST | Cold Weather Advisory | MTR | 38 hr |
| Dec 5, 7:04 AM PST | Dense Fog Advisory | MTR | 4 hr |
| Dec 12, 5:27 AM PST | Dense Fog Advisory | MTR | 6 hr |
| Dec 12, 8:06 PM PST | Dense Fog Advisory | MTR | 15 hr |
| Dec 13, 9:01 PM PST | Dense Fog Advisory | MTR | 14 hr |
| Dec 14, 8:31 PM PST | Dense Fog Advisory | MTR | 14 hr |
| Dec 17, 5:10 PM PST | Dense Fog Advisory | MTR | 18 hr |
| Dec 19, 2:18 PM PST | Flood Watch | MTR | 7 days |
| Dec 21, 8:49 PM PST | High Wind Watch | MTR | 21 hr |
| Dec 22, 8:37 AM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 22, 5:59 PM PST | High Wind Warning | MTR | 37 hr |
| Dec 22, 5:59 PM PST | Wind Advisory | MTR | 19 hr |
| Dec 23, 1:09 PM PST | Wind Advisory | MTR | 18 hr |
| Dec 24, 3:04 AM PST | Severe Thunderstorm Warning | MTR | 22 min |
| Dec 24, 3:18 AM PST | Areal Flood Advisory | MTR | 3 hr |
| Dec 24, 5:08 AM PST | Wind Advisory | MTR | 29 hr |
| Dec 24, 5:15 PM PST | Special Weather Statement | MTR | 30 min |
| Dec 24, 11:46 PM PST | Mesoscale Discussion | SPC | 2 hr |
| Dec 25, 2:48 AM PST | Areal Flood Advisory | MTR | 5 hr |
| Dec 25, 3:01 AM PST | Flash Flood Warning | MTR | 3 hr |
| Dec 25, 3:12 AM PST | Severe Thunderstorm Warning | MTR | 33 min |
| Dec 25, 4:11 PM PST | Mesoscale Discussion | SPC | 2 hr |
| Dec 28, 11:13 AM PST | Cold Weather Advisory | MTR | 22 hr |
| Dec 29, 2:38 AM PST | Coastal Flood Advisory | MTR | 6 days |
| Dec 29, 11:36 AM PST | Cold Weather Advisory | MTR | 21 hr |
| Dec 29, 9:04 PM PST | Dense Fog Advisory | MTR | 12 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 | 2 |
| Mesoscale Discussion | 2 |
| Special Weather Statement | 4 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flash Flood Warning | 1 |
| Flood Watch | 4 |
| Areal Flood Advisory | 18 |
| Heat | |
| Heat Advisory | 4 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 1 |
| Cold Weather Advisory | 3 |
| Frost Advisory | 18 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 2 |
| Wind Advisory | 15 |
| Fog and smoke | |
| Dense Fog Advisory | 13 |
| Coast and beach | |
| Coastal Flood Advisory | 17 |
| Tsunami Advisory | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20242026
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.