Alert archive / California / Mesoscale Discussions
Mesoscale Discussions in California, 2025
14 mesoscale discussions in 2025. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of mesoscale discussions reaches back to 2003.
Mesoscale Discussions by county
Each county as a circle sized by its count in 2025. Tap one for its archive.
- Mesoscale Discussions
- 14
- Busiest month
- December6 mesoscale discussions
- Busiest day
- December 24, 20253 mesoscale discussions
Over time
By month
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 | Counties | Lasted |
|---|---|---|---|---|
| Feb 13, 12:46 PM PST | Mesoscale Discussion | SPC | Amador, Calaveras, Merced, Sacramento, San Joaquin, Stanislaus and 2 more | 119 min |
| Mar 12, 7:03 PM PDT | Mesoscale Discussion | SPC | Alpine, El Dorado, Nevada, Placer, Sierra | 4 hr |
| Apr 1, 1:54 PM PDT | Mesoscale Discussion | SPC | Amador, Butte, Calaveras, Sacramento, San Joaquin, Sutter and 3 more | 2 hr |
| Jun 30, 3:35 PM PDT | Mesoscale Discussion | SPC | Modoc, Shasta, Siskiyou | 115 min |
| Jul 25, 2:57 PM PDT | Mesoscale Discussion | SPC | Alpine, Lassen, Modoc, Plumas, Sierra | 2 hr |
| Sep 18, 11:48 AM PDT | Mesoscale Discussion | SPC | Imperial, Riverside, San Bernardino | 2 hr |
| Oct 13, 9:44 PM PDT | Mesoscale Discussion | SPC | San Luis Obispo, Santa Barbara, Ventura | 2 hr |
| Oct 14, 5:42 AM PDT | Mesoscale Discussion | SPC | Los Angeles, Ventura | 93 min |
| Dec 24, 2:05 AM PST | Mesoscale Discussion | SPC | San Mateo, Santa Cruz | 85 min |
| Dec 24, 5:11 AM PST | Mesoscale Discussion | SPC | Santa Barbara, Ventura | 94 min |
| Dec 24, 7:22 AM PST | Mesoscale Discussion | SPC | Orange | 113 min |
| Dec 24, 11:46 PM PST | Mesoscale Discussion | SPC | Alameda, Contra Costa, Lake, Marin, Mendocino, Napa and 5 more | 2 hr |
| Dec 25, 2:12 AM PST | Mesoscale Discussion | SPC | Marin, San Mateo, Santa Cruz | 63 min |
| Dec 25, 4:11 PM PST | Mesoscale Discussion | SPC | Alameda, Contra Costa, Lake, Marin, Mendocino, Monterey and 8 more | 2 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- San Mateo County4
- Santa Cruz County4
- Ventura County3
- Marin County3
- Amador County2
- Calaveras County2
- Sacramento County2
- San Joaquin County2
- Sutter County2
- Yuba County2
- Alpine County2
- Sierra County2
- Modoc County2
- Santa Barbara County2
- Alameda County2
- Contra Costa County2
- Lake County2
- Mendocino County2
- Napa County2
- Santa Clara County2
- Solano County2
- Sonoma County2
- Merced County1
- Stanislaus County1
- El Dorado County1
- Nevada County1
- Placer County1
- Butte County1
- Tehama County1
- Yolo County1
- Shasta County1
- Siskiyou County1
- Lassen County1
- Plumas County1
- Imperial County1
- Riverside County1
- San Bernardino County1
- San Luis Obispo County1
- Los Angeles County1
- Orange County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe 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.