The Great 2017 Southern California Outbreak
Tornado - 228.jpg
The M6 tornado near Glendale, California
Date of tornado outbreak: April 16, 2017 - April 25, 2017
Duration1: 9 days
Maximum rated tornado2: M6 tornado
Tornadoes caused: 248
Damages: $1.75 trillion (2015 USD)
Fatalities: 646,812
Areas affected: Southern California, including Los Angeles and San Diego

1Time from first tornado to last tornado
2Most severe tornado damage; see Fujita scale

  • The great M6 tornado begins to rip through downtown Los Angeles.
  • The San Diego M-3
  • The great M3 tornado rips though a neighborhood near San Diego.
  • The Riverside F-12
  • The Beverly Hills F-11
  • The F11 Beverly Hills tornado is about to completely demolish the Hollywood sign.
  • The Chino Hills F-9
  • The Moreno Valley F-9
  • Two tornadoes, both F6, cause extreme devastation near downtown Los Angeles.
  • Twin tornadoes, the left one an F4 and the right one an F5, wreck havoc near Riverside.
  • A weaker F3 tornado near Los Angeles
  • An F0 tornado near San Bernardino

The Great 2017 Southern California Outbreak was the most devastating tornado outbreak ever recorded, affecting most areas of Southern California including downtown Los Angeles and San Diego and leaving catastrophic destruction in its wake. The strongest tornado was an M6 tornado that tore through Orange County and Los Angeles County, with a few other tornadoes going past F10 intensity. Another 12 tornadoes reached F6 or greater. During this great outbreak, most of the Los Angeles Greater Area and other areas of SoCal were utterly devastated by the tornadoes, with a grand total of $1.75 trillion dollars in damage and a record 646,812 deaths being caused throughout this cataclysmic outbreak. The tornadoes going past F5 were the main cause for the record high damage and deaths, and this outbreak was among the worst natural disasters in history. A total of 248 tornadoes were produced during this outbreak, and it lasted 9 days, from April 16 to April 25.

Imagine if this actually happened...

Tornado count


248 48 (4 anticyclonic) 39 (1 anticyclonic) 43 49 (2 anticyclonic) 34 19 6 3 1 2 0 1 1 0 0 1 0 0 1

The 10 strongest tornadoes of the outbreak

List of confirmed tornadoes - April 16 - 25, 2017
Location of Peak Intensity
Time of Peak Intensity (PDT)
Path length
M6 N of Los Angeles 5:45 PM, April 18, 2017 190 miles 268,915 deaths - A massive tornado, tracking from San Clemente all the way to Bakersfield, was responsible for extremely massive devastation throughout its very long track. It was the most devastating tornado in history, destroying virtually every single house along its track through the LA metro area! It first moved through Orange County, later heading towards downtown Los Angeles and reaching its peak intensity near Glendale. It then moved through the San Fernando Valley, Santa Clarita, and survived mountain ranges to make it to the Central Valley as a weaker tornado. Once it reached Bakersfield, it finally dissipated.
M3 NE of San Diego 2:50 PM, April 20, 2017 80 miles 48,275 deaths - A massive tornado caused catastrophic damage to houses and buildings throughout the San Diego Greater Area, along its path from the Mexican border to Temecula.
F12 SE of Riverside 8:06 PM, April 19, 2017 65 miles 16,916 deaths - A very powerful tornado ripped through the Inland Empire from Temecula to north of Fontana, causing very massive destruction along its track and flattening a countless number of homes in the Inland Empire.
F11 NE of Beverly Hills 7:21 PM, April 18, 2017 20 miles 9,469 deaths - This tornado, tracking from NW of downtown Los Angeles to Interstate 405, caused the complete destruction of the Hollywood Sign and the Universal Studios theme park when it tracked through the hills north of Hollywood and Beverly Hills. It also flattened thousands of houses and caused massive devastation throughout the area.
F9 S of Chino Hills 11:05 AM, April 22, 2017 40 miles 824 deaths - This powerful tornado caused lots of devastation as it tracked from east of Corona to San Dimas while remaining mostly in hilly regions.
F9 N of Moreno Valley 3:04 PM, April 20, 2017 85 miles 5,508 deaths - A very long-tracking tornado formed near Anza and moved through Hemet, Moreno Valley, San Bernardino, and the San Gabriel Mountain foothills. It flattened a countless number of houses through its long track and resulted in thousands of deaths throughout the Inland Empire.
F8 NW of Lake Forest 1:30 PM, April 23, 2017 50 miles 412 deaths - Formed east of San Juan Capistrano and moved through the foothill regions of the Santa Ana Mountains before entering the mountains. It damaged lots of towns along the Santa Ana Mountain's foothills, including Rancho Santa Margarita and Lake Forest.
F7 NW of Moorpark 5:18 PM, April 21, 2017 65 miles 513 deaths - This destructive tornado formed in the Santa Monica Mountains and moved through Thousand Oaks, Moorpark, Santa Paula, and Ojai, causing plenty of devastation to houses throughout the region.
F7 W of Hemet 10:27 AM, April 24, 2017 70 miles 468 deaths - Formed west of Camp Pendleton and passed through Wildomar, Menifee, Beaumont, Cherry Valley, entered the San Bernardino Mountains and dissipated. It destroyed many houses and buildings, but otherwise, it remained mostly in barely-populated areas.
F7 N of Lake Forest 6:50 PM, April 19, 2017 28 miles 75 deaths - This tornado affected only a little bit of homes through its path from north of Laguna Beach, to between Irvine and Lake Forest, to Portola Hills, and then it entered the Santa Ana Mountains. The towns it did affect were devastated from the tornado, but it still didn't cause much deaths compared to the stronger tornadoes above.

Meteorological history

During April 13-16, 2017, a massive burst of moisture from the Gulf of Mexico and the Great Plains rushed towards California. At that time, a historic tornado outbreak was already occurring in Great Plains, but by April 16, severe thunderstorms associated with the westward-moving moisture began spawning tornadoes in Southern California. A day later, a combination of extremely moist air, a perfect jet stream, and very favorable atmospheric conditions over SoCal were certainly for explosive tornadic development, and by then, the massive thunderstorms in the Great Plains, which were producing unusually extreme tornadoes of F8+ intensity during April 9-15, moved directly westward towards SoCal and strengthened. The combination of the moisture and the westward-moving severe tornadic cells produced the perfect conditions for an extremely unusual and historic tornado outbreak to break out in Southern California. On April 18, a tornado associated with this outbreak strengthened to Mach 6 intensity, the strongest winds ever recorded anywhere on Earth, and it moved through populated areas in SoCal, causing extreme devastation. Another tornado of F11 devastated Beverly Hills that day too. As the days progressed, the extreme conditions persisted and continued producing extremely powerful tornadoes in SoCal, with many tornadoes going pass F6 intensity along with extreme devastation, and one of them strengthened to Mach 3 intensity, the second and last tornado of this outbreak reaching Mach winds. By April 24, the outbreak has finally calmed down, with the last F7+ tornado forming west of Camp Pendleton. On April 25, the outbreak was almost done for good, and the strongest reported tornado of that day reached F3 intensity. During that night, the outbreak finally moved out of Southern California. During the outbreak, massive trails of devastation dominated SoCal, and over a trillion dollars worth of damage was caused after many of the tornadoes virtually flattened large swaths of SoCal. The devastation of this outbreak will never be forgotten, and many areas will have an extremely long road of recovery to come.