On this day in 2011, an insidious tornado tore through the southern portion of Joplin, Missouri.
Insidious because of how quickly it formed, where it formed, how intense it became and where it traveled.
Even with all of the technology at our disposal, 158 people lost their lives (NWS statistics). Here is a list of the highest single tornado death tolls on record.
Slideshow of Radar Images (Base Reflectivity) Zoomed in on Joplin:
I would recommend reading the National Weather Service “Service Assessment Report” for the Joplin tornado (PDF file). A panel of individuals performed an assessment (as they do for most major tornadoes and/or outbreaks) of the events leading up to the this tornado. There are some valuable insights in this paper.
The assessment report states that many folks sought a “second opinion” before deciding whether the tornado warning was important enough or close enough to take action. It is human nature to want to know what is going on around you.
Slideshow of 3D Rotation:
The amount of time it took for this tornado to become a monster was very short. The tornado was low to the ground, perhaps indistinguishable to the untrained eye from a low cloud near the ground and made worse if trees and building blocked the view of the horizon. It started on the edge of very densely populated city (couldn’t see it coming for miles and minutes beforehand).
It was really the second storm to threaten the Joplin area that evening (read the assessment report) which may have caused some confusion.
The Joplin tornado had a very pronounced “debris ball” in the hook echo. A debris ball is a very sobering thing to look at because it tells you the radar beam is actually reflecting off of pieces of the destruction.
This video shows the beginning of the Joplin tornado and sums up how quickly it spun into existence: