Significant hail but no damage reports after Northern California tornado warning

A storm that triggered a tornado warning in portions of four counties south of the Sacramento area Thursday afternoon brought significant hail but no reported damage, authorities confirmed.

The warning, which was issued around 4:30 p.m. and expired at 6 p.m., was in place for northeastern San Joaquin County, northern Stanislaus County, west central Calaveras County and southwestern Amador County, according to the National Weather Service’s Sacramento office.

The storm system dumped 1 to 3 inches of small hail in the Valley Springs area of Calaveras County, said Craig Shoemaker, a meteorologist with the weather service in Sacramento.

Radars showed the storm had “very strong rotation,” a possible sign of tornado development, according to the weather service.

Forecasters also viewed videos and pictures of large wall clouds and funnel clouds but had not confirmed whether a tornado touched down in the area Thursday, Shoemaker said.

Although uncommon, weather conditions sometimes produce tornadoes around the Golden State.

A twister touched down in the El Dorado Hills area in December 2015, according to the weather service. Authorities reported the tornado brought 80-90 mph winds, damaged a roof and downed trees.

In December 2019, a fast-moving winter storm triggered a brief tornado warning for parts of the Santa Barbara County coast.

Tornado activity was first detected offshore near Montecito and “circulation held together as it reached land, but there were no reports of damage,” the weather service said at the time.

The same storm system also spawned a small, narrow twister that touched down near Ventura Harbor, downing trees and causing minor damage to buildings, the weather service said.

One of the most well-known tornadoes to hit Southern California tore through downtown Los Angeles in 1983.

The twister stripped part of the roof off the Los Angeles Convention Center before roaring south along Broadway, ripping apart houses, smashing brick storefronts and overturning cars. More than 150 buildings were damaged. Thirty-two people were hurt.

In 1991, a tornado ripped the roofs off several homes in Irvine.

The Great Lake Forest Tornado roared through the community without warning at the dinner hour on Jan. 17, 1993. The twister tore roofs off houses, flung boats out of a man-made lake and hurled a woman 75 feet through the air. No one was seriously hurt.

Most California tornadoes originate in the Pacific as winter thunderstorms. As some storms approach the coast, cold air above the ocean mixes with warmer air on land, resulting in the kind of climate instability that can cause tornadoes.

Further information about Thursday’s storm in Northern California wasn’t available.