A large and dynamic storm system bought widespread impacts across much of the United States at the end of February 2023. In the Western United States, heavy snow, hail, and gusty winds affected many areas. This led to the partial closure of several major highways, including I-205 in the Portland, Oregon metropolitan area, as well as numerous fatal accidents on other highways. Hundreds of flights were cancelled, thousands of people lost power, and multiple sporting events were postponed. In the Great Plains and Mississippi Valley, significant impacts from severe weather occurred. A severe squall line produced destructive straight-line winds in the St. Louis metropolitan area on February 23. The most impactful day in terms of severe weather was on February 26, when a powerful line of severe thunderstorms containing damaging straight-line winds and numerous embedded tornadoes impacted the Texas Panhandle, southern Kansas, and most of the state of Oklahoma. Dozens of instances of large hail, damaging wind gusts, and multiple tornadoes were confirmed with this event, including an EF2 tornado that killed a person in Cheyenne, Oklahoma. A wind gust from straight-line winds was reported in Memphis, Texas, which was the highest wind gust since the August 2020 Midwest derecho. Five of these tornadoes formed in the Oklahoma City metro area, including a high-end EF2 tornado that caused severe damage in the southeastern part of the city of Norman. The event set the record for the most tornadoes ever recorded in Oklahoma in the month of February since modern records began in 1950. More tornadoes touched down in Illinois the next day, including some in the Chicago metropolitan area. In addition to the severe weather impacts, parts of the Midwestern United States also received periods of heavy snowfall and gusty winds along with ice, causing dozens of accidents, knocking out power, and canceling hundreds of flights. The Northeastern United States was also affected by heavy snowfall.
Meteorological synopsis
An upper-air disturbance, combined with high-altitude cold air and low pressure, dove southeast from British Columbia into the Western United States on February 21.
Impacts + Fatalities from non-tornadic effects by state State Fatalities Ref. California 1 Colorado 3 Michigan 1 Missouri 1Weather blamed for one fatality, wrecks, downed lines in Cape, Southeast Missourian, February 23, 2023 Nevada 5 Oregon 2 Vermont 1 Total 14 Along the path of the winter storm, countless school districts across numerous states cancelled or delayed classes. Inclement weather forced the closure of many roadways. Weather watches and warnings were issued for snowfall, freezing rain, heavy rainfall, strong winds, and extreme cold.
Western United States Winter storm watches were hoisted for mountainous regions of the California Bay Area, the first since 2011, while only the second ever blizzard warning was issued for Los Angeles County, and the first blizzard warning ever issued by the National Weather Service of San Diego.National Weather Service San Diego issues first-ever blizzard warning, Fox5 San Diego, February 24, 2023 Evacuation warnings were issued for Ventura County due to anticipated flooding and debris flows. In Arizona, American Airlines issued travel waivers for Flagstaff Pulliam Airport in anticipation of strong winds. Farther north in Oregon, the Portland Timbers of Major League Soccer postponed their opening match of the 2023 season due to the storm; it had been scheduled to take place on February 25 but was moved to February 27.
Oregon
In Oregon, snow fell in Troutdale, Tigard, Stayton, Cathedral Park, Chapman Square, and Beaverton, in which the latter received of snow. Portland recorded of snow, their largest accumulation on record so late in the winter season and the second-largest calendar day observation in the city's history.Portland metro sees heaviest snowfall on record late in season, KGW, February 23, 2023 For much of the Portland metro area, the heavy snow came as a surprise with some weather models having struggled to capture eventual location of the system. On US 26 near Portland, more than 70 cars were abandoned because of the difficult driving conditions. Snow and ice led to the closure of I-205 over the Glenn L. Jackson Memorial Bridge, as well as a stretch due to stalled vehicles from high snow accumulations with several other highways closing in Oregon, including US 101 and OR 34, where downed trees blocked the routes. Around 400 flights were cancelled at Portland International Airport. Two deaths occurred in the city. Snow led to the suspension of Newport's seafood and wine festival. MAX Light Rail trains and TriMet buses were stalled, causing the delay of passengers arriving to their destinations. The inclement weather forced the closure of the City Hall in Lincoln City. At least 15,000 power outages occurred across the state, with 9,000 occurring in just the Portland, Oregon metropolitan area alone.Historic winter storm turns deadly, freezing temperatures persist across Pacific NW, KATU, February 23, 2023
California
In California, there were at least 172,000 power outages. Wind gusts of more than were recorded, with San Francisco International Airport recording a wind gust of . Trees and power lines were knocked, down, including a tree which fell on several cars and an apartment building in Manhattan Beach. A tornado was also reported near Whittier on February 23. A 1-year-old was critically injured after a tree fell on top of them in Boulder Creek. For the first time in several years, hail fell on the Hollywood Sign. Cars were stranded on I-15 for several hours as snow, hail, and high winds impacted travel. There was a 20-car pileup on I-10 in Yucaipa, causing several injuries, while a 12-car pileup occurred on SR 189 near Crestline. An accident in Tujunga that left one person dead and two others injured may have been related to the storm; however, the exact cause of the accident is under investigation. Major League Soccer's 2023 season opener on February 25 at the Rose Bowl in Pasadena was rescheduled to July 4 due to the worsening weather. Snow fell at unusually low elevations across Greater Los Angeles, (including in the upper reaches of the Crescenta Valley), the High Desert, and in parts of Northern California such as Eureka, Crescent City, Ukiah, Lakeport, and Cloverdale. High seas led to the closure of the Redondo Beach pier. Los Angeles International Airport temporarily instituted a ground stop due to the thunderstorms. At Disneyland, the first performance of “Magic Happens” since 2020 was postponed due to the storm.First Performance of ‘Magic Happens’ Since 2020 Cancelled Due to Inclement Weather at Disneyland, DLNewsToday, February 24, 2023 Snowy conditions in the Bay Area also led to road closures along SR 17, SR 29, and SR 128. In the aftermath of the storm, Yosemite National Park closed and remained closed through March 17.Yosemite National Park remains closed amid winter storm; more snow expected this weekend, ABC7NY, March 6, 2023Yosemite Will Finally Reopen Weeks After Being Buried In 15 Feet of Snow, The Inertia, March 17, 2023 During the storm, San Francisco fell to a record low of on February 23, following a record cold high of on February 22.San Francisco Has Set Cold-Weather Records For Three Days In a Row , SFist, February 24, 2023 A rain squall in Los Angeles set temperatures to on February 23, tying a daily record.LAX sets record-low temperature amid winter storm, CBS News, February 23, 2023
Elsewhere In Arizona, 20,000 power outages were reported, with 9,000 in Coconino County and 5,000 in Maricopa County. Over of I-40 closed, from the New Mexico state line until the junction with US 93. In New Mexico, I-40 was also closed to the west of Gallup. In Albuquerque, winds gusted up to , which left over 12,000 customers without electricity. In Utah, at least 110-120 crashes were reported, including on I-15, and I-84. In neighboring Nevada, a Care Flight medical flight crashed shortly after takeoff near Stagecoach, killing all five occupants. Weather at the time of the crash consisted of steady snow with winds of . An investigation by the National Transportation Safety Board is ongoing to determine the cause of the accident. In Colorado, over 200 flights were cancelled at Denver International Airport. Crashes were reported on I-25 and I-70, causing road disruptions. After the storm moved through, Denver set a record for the coldest temperature on record for February 23, at .Denver sets new record low Thursday morning as temperatures tumble into negatives, ABC Denver 7, February 23, 2023 On February 25, an avalanche near the Vallecito Reservoir in La Plata County killed two people while another killed one person in La Manga Pass. Northward in Wyoming, a large portion of I-80 and I-90 was closed. Snow stranded drivers and caused difficult conditions for first responders, including a near-miss when a semi almost hit a Wyoming Department of Transportation trooper. In Washington, snow fell in the Cascade Range and the Northern Rockies. The heavy snows, combined with wind gusts, hindered efforts to rescue four people from an earlier avalanche, with only one surviving. In Seattle, after the storm passed, a record low high temperature of was set on February 23, breaking the record from the previous year, while a record low temperature of was set the next morning.Seattle hits record cold for February 23, KWOU, February 24, 2023 In Spokane, the high on February 23 was also a record, at only .The cold broke records, but conditions are set to improve!, KHQ, February 24, 2019
Midwestern United States In South Dakota, health departments, including Sanford Health and Avera Health, announced closures in Sioux Falls. Governor Kristi Noem ordered state government executive branch offices closed in 36 counties. Parts of I-90 and I-29 closed.Sections of I-90 and I-29 in South Dakota Reopening Thursday Afternoon, ESPN Sioux Falls, February 23, 2023 To the east, the National Weather Service forecast office in the Twin Cities warned of a "historic" winter storm. About 1,600 free parking lots were made available in Minneapolis because of the inclement hazardous weather. Numerous airlines, such as Delta, Southwest, United, and American airlines issued travel waivers in Minneapolis–Saint Paul International Airport. The Weather Prediction Center issued a rare extreme impact risk area. Minnesota Governor Tim Walz issued a peacetime emergency and ordered emergency executive orders to the National Guard, Minnesota State Patrol, and Minnesota Department of Transportation. Snow emergencies were issued in the cities of Brooklyn Park, Crystal, and New Hope. Numerous businesses and stores, including Lunds & Byerlys, were closed. A no travel advisory was issued for several counties, including Brown, Cottonwood, Jackson, Martin, and Watonwan counties. In Wisconsin, Green Bay–Austin Straubel International Airport cancelled all flights on February 22 and most flights on February 23.