Why Hurricane Milton spawned so many tornadoes

Why Hurricane Milton spawned so many tornadoes

Megan Bartels

Hurricane Milton hit Florida as a Category 3 storm, bringing severe storm surge and heavy rain to the central part of the state. Given that discussions about hurricane danger have focused on flooding, rainfall, and high winds, residents further south received tornado warnings (more than 100 in all) from local National Weather Service offices. I was surprised.

But Hurricane Milton’s power and size, combined with underlying atmospheric factors to spawn dozens of tornadoes, created what Ohio State University atmospheric scientist Jana Hauser called “Milton’s near-perfect storm scenario.” I’m here.

Whether within a hurricane or independently, tornadoes form when air spinning near the ground is pulled up into the atmosphere by a thunderstorm, Hauser said. Air gains speed as it moves upward.

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In general, tornadoes are particularly likely to form in large hurricanes like Milton, which had tropical storm winds up to 405 miles from its center late on October 9th.

Hurricanes have their own rotating winds, with wind speeds being highest, especially in the eyewall at the center of the hurricane. Weak tornadoes can form near the center of a hurricane just before it makes landfall, as winds adapt to interacting with rough land rather than a relatively smooth ocean surface.

But that’s not where to look for more powerful tornadoes, like the one produced by Milton, said Stephanie Zick, a meteorologist at Virginia Tech. It is said to be “particularly strong” for a tornado caused by a hurricane. They form at the edge of the storm, as much as 100 miles from the eye, in an outer band of intense rain where supercell thunderstorms (large rotating thunderstorms) are active. Additionally, Hauser said the environment in which Milton swirled was conducive to tornado formation, thanks to the presence of pockets of warm, humid air and bands of wind into which the storm could blow. are.

Zick said tornado conditions were also strongest on the east side of the storm. Combined with the distance from the hurricane’s eye, the majority of tornado reports were in south Florida.

Despite the commotion caused by the tornadoes, Milton was not the hurricane that produced the most tornadoes this year, Hauser said. That dubious honor goes to Hurricane Beryl. Hurricane Beryl hit the Texas Gulf Coast in early July and then moved northeast across the United States, with its remnants eventually flooding Vermont. Hauser said Beryl spawned 68 tornadoes, nearly double Milton’s preliminary tally of 38. (she points out) The hurricane with the most tornadoes on record was Hurricane Ivan, which circled the southeastern United States. In September 2004, there were 120 tornadoes.

Tornadoes caused by hurricanes are a notable example of how hurricanes pose multiple threats to populations. Not only long deluges occur, but also sudden tornadoes.

And sometimes threats are involved. As Milton approached Florida, it encountered chaotic winds that tore at its structure, and the storm weakened from a Category 5 with sustained winds of 160 miles per hour to a Category 3 with winds of approximately 120 miles per hour upon landfall. But that increased the size of the storm and created a more troubling wind pattern at its edges, which led to the tornado explosion, Hauser said.

“If it weren’t for those winds, Milton probably would have made landfall as a Category 5 hurricane,” she said. “But in that case, we probably wouldn’t have had as many tornadoes as we actually saw inland.”