Tornado debris can travel surprisingly far after a violent storm
How far can tornado debris travel? Farther than you might think!
Intense tornadoes are capable of producing destructive winds of more than 300 km/h. These whirlwinds can reduce the mightiest oak tree to splinters and entirely demolish a solidly built home.
All that debris doesn’t stick around where it came apart. A tornado can loft debris hundreds of kilometres away from where it originated—and some of that debris is incredibly heavy.
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Tornadoes suck upward like a vacuum
Tornadic winds are capable of producing tremendous damage on their own. But these storms are unique in that they suck upward rather than just blowing wind around in a circle.
This upward component of the violent winds provide tornadoes the leverage they need to peel roofs from homes, uproot trees, and toss vehicles as if they were toys. Winds within a twister extend from the surface deep into the heart of its parent thunderstorm.
While most debris falls back to the ground in a hurry, some objects can loft high into the thunderstorm—and then take a long ride on upper-level winds.
It’s common after a violent tornado to see debris travel dozens, if not hundreds, of kilometres downwind from the point of damage. This is called debris fallout—and it’s actually possible to see it on weather radar.
The radar image above shows the debris fallout from a violent tornado in southern Mississippi on April 12, 2020. A powerful EF-4 tornado damaged or destroyed thousands of structures along its 110-kilometre path.
Special technology embedded in weather radar allows us to ‘see’ debris suspended in the atmosphere during and after a tornado. The tornado itself is visible as a tight ball of debris. Strong upper-level winds blew a tremendous amount of debris downwind, which the radar was easily able to detect.
It takes tremendous forces to loft heavy debris like metal and wood long distances. A strong EF-2 tornado in April 2018 struck Greensboro, North Carolina, and tossed heavy pieces of corrugated metal nearly 30 kilometres downwind.
Lighter objects like envelopes and photographs are known to travel hundreds of kilometres.
One paper published in 1998 found that pieces of paper had been transported up to 335 km downwind from a tornado.
Another study in 1995 found that a twister in Barneveld, Wisconsin, had transported “traceable” pieces of paper—such as invoices and personal cheques—177 km away from the damaged town.
Header image of tornado damage in Mississippi on April 12, 2020, courtesy of NOAA/NWS.