A satellite tornado is a tornado that revolves around a larger, primary tornado and interacts with the same mesocyclone. Satellite tornadoes occur apart from the primary tornado and are not considered subvortices; the primary tornado and satellite tornadoes are considered to be separate tornadoes. The cause of satellite tornadoes is not known. Such tornadoes are more often anticyclonic than are typical tornadoes and these pairs may be referred to as tornado couplets. Satellite tornadoes commonly occur in association with very powerful, large, and destructive tornadoes, indicative also of the strength and severity of the parent supercell thunderstorm.
The tornado outbreak sequence of May 5–10, 2015 was a six-day outbreak of tornado activity that affected the Great Plains of the United States in early May 2015. On May 6, strong tornadoes impacted the Oklahoma City area, along with rural parts of Kansas, Texas, Arkansas, South Dakota, and Nebraska. The outbreak coincided with major flooding, with large amounts of rain falling in parts of Nebraska, Kansas, Oklahoma, and Texas. The National Weather Service forecast office in Norman, Oklahoma issued a "flash flood emergency" for Oklahoma City following record-breaking rainfall that occurred in the area that evening. The outbreak sequence resulted in five tornado-related deaths, along with two flood-related deaths. A total of 127 tornadoes were confirmed and rated as a result of this outbreak sequence. Damage from the outbreak was estimated at $1.5 billion.
Between April 28 – May 1, 2017, a series of severe weather events affected the Central United States, producing life-threatening flooding and a major tornado outbreak. It formed out of a disturbance in the Southwestern United States on April 28, and caused significant impacts, including a heavy snowstorm in the Rockies, and other types of severe weather. Up to 3 feet (36 in) of snow fell on the cold side of the system, and up to a foot of rain fell in and around the central parts of the nation.
A prolonged period of intense tornado activity affected the Great Plains, Great Lakes, and Ohio Valley during May 15–20, 2017. This outbreak sequence was the most prolific tornado event of 2017 in terms of number of tornadoes. It is also notable for producing the longest-tracked tornado in Wisconsin state history: an intense EF3 tornado that remained on the ground for over 82 miles (132 km) and killed one person while causing major damage near Chetek and Conrath. Overall, the outbreak sequence resulted in two deaths and several injuries.
The tornado outbreak of November 30 – December 2, 2018 was a late-season tornado outbreak that occurred across portions of the West South Central states and Midwestern United States. As a potent shortwave trough moved across the southern portions of the country, it was met with ample moisture return and destabilization, resulting in widespread severe thunderstorms that produced damaging winds, hail, and tornadoes. The event began late on November 30 in Oklahoma, spreading east and resulting in one fatality in Aurora, Missouri. Several tornadic supercells moved across portions of Illinois on December 1, and resulted in 29 confirmed tornadoes. This outbreak was the largest December tornado event on record in Illinois history, surpassing the December 1957 tornado outbreak sequence. The most significant tornado of the event was an EF3 that impacted Taylorville, Illinois, damaging or destroying hundreds of structures and injuring 22 people.
The March 2019 North American blizzard was a powerful Colorado Low that produced up to two feet of snow in the plains and Midwest. Rapid snowmelt following the storm caused historic flooding, and some areas received hurricane-force wind gusts. Comparable to the 1993 Storm of the Century, the storm was labeled a bomb cyclone after barometric pressure readings dropped in excess of 24 mbar (0.71 inHg) over a 24-hour period. After the storm entered Colorado from its origination in Arizona, the pressure dropped more than 30 mbar (0.89 inHg) and rapidly intensified over the western High Plains. The severe storm set new all-time record low barometric pressure readings in Colorado, Kansas and New Mexico. The storm itself killed only one person in Colorado, but flooding caused by the storm killed at least 3, one in Iowa and at least two in Nebraska and left ~140,000 without power in Texas.
A significant severe weather and tornado outbreak affected multiple regions of the Eastern United States in mid-April 2019. Over the course of 40 hours, 75 tornadoes touched down. The outbreak produced numerous strong tornadoes throughout portions of the Deep South, while additional significant tornadoes occurred as far north as Ohio, Pennsylvania, and Delaware. The most significant tornado of the event was a long-tracked, high-end EF3 tornado that struck Alto, Texas and killed two people. Numerous weak tornadoes were also confirmed, along with numerous reports of hail and damaging straight line winds.
The tornado outbreak of April 17–19, 2019 was a multi-day, widespread severe weather event stretching from the South-Central United States to the East Coast of the United States. On the heels of a significant tornado outbreak just a few days prior, another potent upper-level trough progressed eastward and served as the impetus for widespread, damaging thunderstorms. The outbreak began on April 17 with several short-lived, generally weak tornadoes across Kansas, Oklahoma, and Texas. The following day, a total of 43 tornadoes were recorded across central Mississippi, tying the Hurricane Rita tornado outbreak as the largest in Mississippi state history. On April 19, the event spread eastward. North Carolina recorded 12 tornadoes, the state's sixth largest outbreak in a single day, while Virginia recorded 16 tornadoes, its third-most in a 24-hour period. Overall, 97 tornadoes were confirmed, the strongest of which was a high-end EF3 tornado that heavily damaged or destroyed homes and outbuildings near Rocky Mount, Virginia. There were no fatalities recorded in association with tornadic activity, but four people were killed by trees that were downed by strong straight-line winds.
Hurricane Ida generated a tornado outbreak as it traversed the Southeastern, Mid-Atlantic, and Northeastern United States. Thirty-five confirmed tornadoes touched down from Mississippi to Massachusetts; one person was killed in Upper Dublin Township, Pennsylvania, and several people were injured in Alabama, New Jersey, and Pennsylvania. The most active and destructive part of the outbreak occurred during the afternoon of September 1, when several strong tornadoes struck Maryland, New Jersey, and Pennsylvania, including an EF3 tornado which impacted Mullica Hill, New Jersey. The same storm later dropped an EF1 tornado that prompted a tornado emergency for Burlington, New Jersey and Croydon, and Bristol, Pennsylvania, the first of its kind in the Northeast, as well as the first such alert associated with a tropical cyclone or it's remnants. This outbreak severely impacted New Jersey and the Philadelphia Metropolitan Area, a region which had been significantly impacted by strong tornadoes from another outbreak that occurred just over a month prior, as well as several weak tornadoes from the remnants of Tropical Storm Fred two weeks earlier. Overall, the 36 tornadoes killed one person and injured seven others.
