A rare tornado tears through part of Los Angeles County. Here's why that's so unusual

By Kaitlyn Radde

Published March 23, 2023 at 9:45 AM CDT

An aerial view of roof damage after a rare confirmed tornado touched down and ripped up building roofs in a Los Angeles suburb on Wednesday in Montebello, Calif.

A tornado tore through Montebello, Calif., in Los Angeles County on Wednesday, damaging buildings and cars in a part of the country that doesn't frequently see tornadoes.

The strongest tornado to impact the Los Angeles Metro area since March 1983 touched down at 11:14 a.m. for two to three minutes, according to the National Weather Service. Its peak winds topped 100 miles per hour and injured at least one person. Nearby Santa Barbara county saw a smaller tornado the same day, with peak winds of about 75 miles per hour, according to NWS.

Why are tornadoes rare in southern California?

California averages 11 tornadoes per year, which typically occur in the spring and fall in the northern half of the Central Valley between Redding and Modesto, according to NWS. The last time NWS in Oxnard rated a tornado was in 2016, according to member station LAist.

There were 44 tornadoes in Los Angeles County from 1950 to 2021, which comes out to less than one per year. Most were classified as weak and resulted in few or no injuries.

There are two key components to tornadoes, according to NWS. The first is instability, with warm, moist air near the ground and cooler dry air higher up. The second is a change in wind speed or direction higher up in the atmosphere. Taken together, these conditions create a rotating updraft, which creates a supercell thunderstorm and eventually a tornado.

Thunderstorms are relatively scarce on the west coast because the Pacific Ocean's cool water more closely mirrors the temperatures higher in the atmosphere. When there isn't a dramatic change in temperature with height, thunderstorms — and, in turn, tornadoes — are less likely.

Weak funnel clouds are more common there, and they occur a couple of times a year without causing notable damage, according to member station LAist. On Tuesday, forecasters in southern California warned of landspouts, which are smaller, short-lived tornadoes that have no rotating updraft.

NWS classifies tornadoes using the Enhanced Fujita scale, which is based on estimated wind speeds and tornado-related damage. The Montebello tornado was classified as EF1, or weak.

But even with that weak rating, it damaged 17 structures, uprooted a tree, snapped a power pole and destroyed car windows, and LAist reports that one person suffered minor injuries. Taking shelter indoors and away from windows is the best way to stay safe in a tornado.