Unusual Tornado Risk For Northern CA

[Randy Zipser]

An unusual risk for tornadoes is expected this week in Northern California. The article below from the San Francisco Chronicle discusses the details:

https://www.sfchronicle.com/weather-forecast/article/california-storm-tornado-risk-21259741.php

 

[Luke Penney]

The weather service was so confident in potential tornadoes that it placed San Francisco in a rare marginal risk for severe thunderstorms three days in advance, the first time the agency had done that for the city in at least a decade.

That phrasing is pretty funny to me living in the Midwest.

 

[Randy Zipser]

That phrasing is pretty funny to me living in the Midwest.

Yea, but I guess people in the Midwest would also view earthquakes and wildfires in the same way as Californians view tornadoes!

 

[John Farley]

Yea, but I guess people in the Midwest would also view earthquakes and wildfires in the same way as Californians view tornadoes!

Depends where in the Midwest. Not so much if you live near the New Madrid or Wabash faults.

 

[Randy Zipser]

Merry Christmas everyone! The SPC Storm Reports show no reported tornadoes in CA so far this week, fortunately. However, as of the latest full summary on 12/24/2025, there were 39 wind reports in CA, including 7 reports of high winds (65 kt+) in CA, NV, and AZ. From what I've seen on legacy news media, the biggest problem thus far has been severe flash-flooding all over the West Coast and inland regions. More active weather is still on-the-way there for the rest of this week, however, so these reports are only partial totals. Let's hope for the best for those affected!

 

[Boris Konon]

"The weather service was so confident in potential tornadoes that it placed San Francisco in a rare marginal risk for severe thunderstorms three days in advance, the first time the agency had done that for the city in at least a decade. "

What the MSM often does not realize this that prior to the mid-1990s when the WSR-88D was deployed, there was this notion that "tornadoes do not occur in California." This is despite days like 11/9/1982 when *seven* tornadoes occurred in the LA Basin. I seem to recall it was said, "the pattern did not fit for tornadoes" or something like that.

The concept of post-frontal, cold upper low mini supercells was not well-known or accepted yet. Also, radars were very limited in the West prior to the WSR-88D.

So in recent decades,, we now know that low-topped convection produces convective wind gusts and tornadoes,in the wet season. and we have the tech to detect it all, so of course, we are going to see alerts/advisories/warnings that we never saw before. Also, standard and practices over time change from social factors alone.