A powerful wind storm and subsequent tornado have caused significant problems in and around San Francisco. This natural disaster has not only led to traffic disruptions and property damage but has also put the safety of residents at risk. Let's take a closer look at the events that unfolded.

Ice Storm in Iowa and Nebraska

Over the weekend, an ice storm struck Iowa and eastern Nebraska. This led to the shutdown of a major interstate highway as cars and trucks slid off the road. At least one person lost their life in a crash due to the icy conditions. The National Weather Service in Des Moines issued a dense fog advisory that was set to remain in effect until 11 a.m. CT on Sunday. Thick fog spread across much of the state, reducing visibility to 1/4 of a mile or less in some areas. By Saturday evening, the ice had predominantly turned into freezing rain, but roads in eastern Iowa were still partially covered with ice or snow.Authorities reported that one person died while driving on icy roads in eastern Nebraska. A 57-year-old woman lost control of her pickup truck on Highway 30 near Arlington and collided with an oncoming truck. The other driver sustained minor injuries in the accident. Washington County, located near the eastern Nebraska border with Iowa and Omaha, was severely affected.In one social media video, a person was seen playing ice hockey in the street as the roads were slick enough. A dense fog advisory was also in place for the region through Sunday at 11 a.m. CT. The National Weather Service in Omaha warned that dense fog was continuing to develop and was expected to last through the next morning. With visibilities below a quarter mile at times and slick spots redeveloping on some roadways, they urged people to exercise caution and drive slowly. Forecasters also warned that untreated roads could refreeze overnight as temperatures dropped.

Tornado in San Francisco and Surrounding Areas

Elsewhere, a storm and wind gusts of up to 60 mph prompted the first tornado warning in San Francisco. Parts of neighboring San Mateo County were also included in the warning, which was issued at 5:51 a.m. to about 1 million people and lifted about 20 minutes later. Later on Saturday, a tornado touched down near a shopping mall in Scotts Valley, about 70 miles south of San Francisco. It overturned cars, toppled trees and utility poles, causing extensive damage.Images uploaded to social media showed at least three vehicles on their hood or side, with their windshields smashed and trees and power lines on the ground. Several people were injured and taken to hospitals. The Scotts Valley Police Department asked people to avoid the area. One of the injured was a battalion chief with the California Department of Forestry and Fire Protection.In San Francisco, some trees toppled onto cars and streets and damaged roofs. The city has not seen a tornado since 2005. The damage is being assessed to determine if the city was indeed hit by a tornado. Meteorologist Roger Gass said this was the first ever warning for a possible tornado in San Francisco and that there might not have been a clear signature on radar for a warning in 2005.The fast-moving storm prompted warnings for residents to take shelter, but few people have basements in the area. Meteorologist Dalton Behringer said the biggest thing is to put as many walls between you and the outside as possible.

Winter Storms in Upstate New York and Nevada

In upstate New York, people were digging out after heavy snow fell. More than 33 inches was reported near Orchard Park, where residents are accustomed to dealing with lake-effect snow this time of year.In Nevada, up to 3 feet of snow was forecast for Sierra Nevada mountaintops. More than a foot (30 cm) fell at some Lake Tahoe ski resorts, and a 112-mph gust of wind was recorded at the Mammoth Mountain resort south of Yosemite National Park.A winter storm warning was set to expire at Saturday at 10 p.m. PT, but an avalanche warning remained in effect into the following night for elevations above 8,000 feet around Tahoe. Interstate 80 was closed along an 80-mile stretch from Applegate, California, to the Nevada line just west of Reno, where rain was falling and a winter weather advisory was in effect through the afternoon. The California Highway Patrol reopened the road in the afternoon for passenger vehicles with chains or four-wheel drive and snow tires, but it remained closed to semitrailer trucks.In western Washington, tens of thousands of people lost electricity Saturday amid a system that brought rain and gusty winds.