2011 Joplin tornado
The 2011 Joplin tornado was a catastrophic EF5-rated multiple-vortex tornado that struck Joplin, Missouri, late in the afternoon of Sunday, May 22, 2011. It was part of a larger late-May tornado outbreak and reached a maximum width of nearly during its path through the southern part of the city. This particular tornado was unusual in that it intensified in strength and grew larger in size at a very fast rate. The tornado tracked eastward across the city, and then continued eastward across Interstate 44 into rural portions of Jasper County and Newton County. It was the third tornado to strike Joplin since May 1971.
Tornadoes of 1973
Notable scientific milestones toward understanding the life cycle of tornadoes occurred in Oklahoma on May 24, 1973, when researchers exploited primitive Doppler weather radar, then under development by the National Severe Storms Laboratory (NSSL), to examine a tornado vortex signature, or TVS, for the first time in history. The scientists, in one of the earliest successful cases of storm chasing, were able to study the evolution of a violent tornado near Union City, and to generate clear visual photography of its entire life cycle, from birth to decay. The successful deployment of Doppler radar to detect tornado formation also pointed the way to the development of a nationwide Doppler radar system, and helped precipitate funding for studies on tornadogenesis.
At the beginning of the year, one of the strongest El Niño episodes since 1950, as defined by sea surface temperatures, was in progress but gradually diminishing, according to the Oceanic Niño Index (ONI). Peak trimonthly anomalies, measured in moving averages, were +1.7 °C above normal for the period December–February 1972 – 1973. The month of January featured clusters of tornado activity along the Gulf Coast, primarily in Texas and Louisiana, as well as part of the Florida peninsula—a pattern not inconsistent with that of El Niño winters in general. The deadliest and strongest tornado of the month was an F3 that struck Caldwell Parish, Louisiana, on January 18, killing one person and injuring two others. It was part of a larger outbreak on the same date that spawned five other significant tornadoes near the Gulf Coast, with 20 total injuries. A smaller outbreak affected Central Florida ten days later, causing damaging F2 tornadoes in the Campbell–Orlando area, with 24 injuries. February featured much less activity, with 10 confirmed tornadoes compared to 33 in January, and no destructive or deadly tornadoes occurred. Outside the U.S., a catastrophic tornado, believed to be an F5, ravaged a small town in Argentina on January 10, causing more than 50 deaths.