2 Tornadoes Touched Down On The Same Day In LA County. How Rare (Or Common) Is That?

Two tornadoes struck the Carson–Compton area around 9 a.m. Thursday as an unseasonably cool storm brought rain to the area. Separated by about 13 minutes, the tornadoes were small but their winds, reaching an estimated 75 mph, managed to do some damage — breaking a power line, tree limbs and scarring buildings in the area.

This is the second time this year that tornadoes have done damage in L.A. County, and it got us wondering — how common are these events? Are they likely to become more common here as the climate changes?

It ain’t Kansas, but … 

Tornadoes don’t show up often, but L.A. County has a long documented history of them. In fact, L.A. is one of the most active tornado locations, not only in the state, but west of the continental divide — in part because when a tornado does show up, there are a whole lot of people around to document it, according to Ariel Cohen, meteorologist in charge at the National Weather Service in Oxnard.

They mostly occur during our cooler months when strong Pacific storm systems move through the area.

There’ve been 45 tornadoes documented here since 1950, according to NOAA’s storm events database. Roughly 30% of the time, more than one tornado occurred during a 24-hour period. The last time we saw multiple tornadoes in the same 24-hour period was back in 2004, when three showed up between Long Beach and Inglewood.

Small twisters, big impact

The majority of them, including the tornadoes on Thursday, were quite weak, sitting at the bottom of the Enhanced Fujita Scale (also known as the EF scale), the rating system used to classify the weather events. And while they tend to pale in comparison to the city destroying tornadoes of the midwest, because of our dense development even small twisters can have an impact.

None of the documented tornadoes killed anyone, though five did result in injuries and 20 resulted in property damage.

There hasn’t been a clear increase in the number of tornadoes in L.A. County over time. More research needs to be done to better understand the impacts of climate change on this specific type of weather event.

“We know that in a warming climate we see the potential for the atmosphere to overall favor more extreme weather events occurring,” said Cohen. “But the exact specifics, there’s a lot more to learn about.”