Tuesday, May 23, 2017

Strange Tornado Paths: They Don't Always Move in the Direction You'd Think

Chris Dolce
Published: May 23,2017

Tornadoes can occasionally take peculiar paths that don't follow the conventional southwest-to-northeast or west-to-east movement that's typically observed.
(MORE: Tornado Central)
Nearly 70 percent of tornadoes across the eastern two-thirds of the U.S. from 1980-2002 moved east (21.6 percent), east-northeast (26.2 percent) and northeast (21.5 percent), according to a 2006 study by Philip W. Suckling of Texas State University–San Marcos and Walker S. Ashley of Northern Illinois University.
Far fewer tornadoes moved southeast (3.2 percent), east-southeast (7 percent), north-northeast (8.1 percent) and north (4.5 percent), the study noted. Tornadoes moving in some type of westerly direction from the east were extremely rare.
The prevailing westerly upper-level wind flow across the United States is the reason most tornadoes move toward the east or northeast. But sometimes atmospheric factors can cause tornadoes to not adhere to that rule. Here's a look at some examples in recent memory.

1.) Bennington, Kansas, May 28, 2013

Perhaps one of the weirdest tornado paths in recent years occurred west of Bennington, Kansas, on May 28, 2013.
The tornado made a loop by first moving southeast, then turning north, before eventually tracking back to the southwest during its approximate one-hour-long life span. This is depicted by the red triangle moving along the red path line in the animation below.
The red triangle depicts the looping path the tornado took near Bennington, Kansas, on May 28,2013. (NOAA)

In addition to the odd track, the tornado caused EF3 damage and was up to a half-mile wide at one point during its existence. Luckily it occurred over a mostly rural area, which prevented widespread damage, but about 100 cattle were lost and some structures were destroyed.
The two radar images in this animation were taken an hour apart and show how the supercell thunderstorm that spawned the tornado barely moved during that time. (NOAA)

(MORE: See How a Tornado Forms)

2.) Southwest Iowa, Aug. 2, 2015

Another weird tornado path occurred in Iowa on Aug. 2, 2015.
The tornado moved south initially, then made a cyclonic loop, before eventually heading back to the northeast. According to the National Weather Service, the path of the tornado was in mostly rural portions of Adams County and Adair County. It was rated EF1, causing some damage to silos and farm buildings about 8 miles north-northeast of Prescott, Iowa.
Storm survey illustration of the strange path the Aug. 2, 2015 tornado took. (National Weather Service Des Moines, Iowa)

3.) Jarrell, Texas, May 27, 1997

A rare F5 tornado that struck Jarrell, Texas, on May 27, 1997 also took a rare path.
The tornado began north of Jarrell and then moved in a south-southwest direction before turning toward the southwest.
The path of the Jarrell tornado from an assessment by the National Weather Service. Red arrows have been added to the graphic in order to show the general southwest direction the tornado moved. (NOAA)
Extreme winds and a slow movement from the Jarrell tornado wiped homes off their foundations and even scoured asphalt off of roads. A total of 27 people were killed in the Double Creek subdivision area near Jarrell.
(MORE: The Most Tornado-Prone Counties)

The foundation of a home is all that remains after the Jarrell, Texas, F5 tornado. (National Weather Service)

4.) Hurricane Katrina, Aug. 29, 2005

An environment conducive to tornadoes moving west or northwest can occur when a hurricane or tropical storm makes landfall.
This is due to the large-scale counterclockwise circulation around the tropical cyclone. Depending on how a hurricane or tropical storm moves inland in relation to the coast, tornadoes that spin up can move in a west or northwest direction.
One such example is this tornado spawned by Hurricane Katrina in Mississippi Aug. 29, 2005. The tornado moved due northwest during its short existence, causing F1 damage southeast of Philadelphia.
The "B" marks the starting point for the tornado and the "E" marks where it lifted off the ground. (NOAA)
Several other tornadoes developed that day in Mississippi that also moved along a similar southeast to northwest path.

MORE: Tornado Risk By Month

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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