Brief EF-1 tornado strikes Oroville, California, causing damage

At approximately 17:40 PST on December 19, 2023, a brief EF-1 tornado touched down in north Oroville, California, uprooting trees and damaging buildings along its path. No injuries were reported.

A strong thunderstorm in north Oroville, California, led to the formation of a brief EF-1 tornado at around 17:40 PST on December 19 (01:40 UTC, December 20). The tornado’s path started near La Palma Drive and Table Mountain Boulevard, traveling north-northeast for approximately two minutes. It caused considerable damage, including to carports and roof shingles, uprooted trees, and snapped limbs. A free-standing light pole was also toppled by the tornado.

The National Weather Service (NWS), in coordination with the Butte County Office of Emergency Management and Public Works, conducted a damage survey on December 20. Video evidence from an apartment complex security camera further confirmed the tornado’s occurrence.

The tornado had an approximate path length of 0.64 km (0.4 miles), a width of 82 m (90 yards), and maximum winds of 145 km/h (90 mph).

Radar detection at the time showed a line of strong thunderstorms with gusty winds, pea-sized hail, and heavy rain.

There was no tornado warning in effect, although thunderstorms had been forecast for several days. The NWS stated that brief weak tornadoes are challenging to detect on radar, making advance warnings difficult. Reports of damage did not arrive until well after the event.

4:47pm 12/20: NWS meteorologists met up with the @CountyofButte Office of Emergency Management to survey damage from Tuesday's storms in Oroville. We determined that a brief EF-1 tornado was responsible for the damage to structures and trees. See graphics for details. #CAwx pic.twitter.com/Dfzd0hMhCv

— NWS Sacramento (@NWSSacramento) December 21, 2023

Some people in #Oroville woke up to intense storm damage inches away from where they were trying to sleep. The aftermath of Tuesday night's storm—now believed to be a #tornado—left locals wondering how sever this storm was and if it can happen again.https://t.co/92Zskiey5E

— KRCR News Channel 7 (@KRCR7) December 21, 2023

Looking ahead, an upper-level low off the Southern California Coast is predicted to bring heavy rain to the region in the days ahead.

The WPC has issued a Moderate Risk of excessive rainfall over parts of Southern California through Friday morning, December 22. This weather pattern is expected to create flash flooding, particularly in narrow canyons, gullies, and burn scars.

As the low moves onshore on Friday, heavy rain will spread to the Southwest while continuing in Southern California, with the WPC issuing a Slight Risk of excessive rainfall for the region from Friday into Saturday morning.

References:

¹ December 19, 2023 Early Evening EF-1 Tornado – National Weather Service Sacramento, California -Issued: 4:30 PM December 20, 2023 – By: Courtney Carpenter, Warning Coordination Meteorologist 

² Short Range Forecast Discussion – NWS Weather Prediction Center College Park MD – 222 AM EST Thu Dec 21 2023

Featured image credit: NOAA/GOES-West, RAMMB/CIRA, The Watchers. Acquired at 01:40 UTC on December 20, 2023