The Science of How Hurricane Milton Became a Monster

At almost every turn, Hurricane Milton offered a surprise.

What began as a small, heavily injured hurricane became an expanding monster that intensified at the fastest pace in recorded history. Storm Threat and Dangerous Waves of Water Florida's west and east coasts, including the flood-prone Tampa Bay metro area – where more than 3 million people live – are particularly at risk.

As the storm developed, record warm seas in the Gulf of Mexico helped increase its intensity. It later increased in volume when undergoing an eye wall replacement process.

See how Milton evolved into such a significant threat.

A peaceful influence

Hurricanes that approach the United States generally follow the same path: Tropical storms move off the west coast of Africa, cross the Atlantic and gain strength as they enter the warm waters of the Caribbean Sea.

But parts of Milton's original story are set in the eastern Pacific. The hurricane formed when the remnants of a tropical depression in the Pacific Ocean reached the eastern Yucatán Peninsula and encountered a stalled front in the Gulf of Mexico. The most recent storm to hit Florida occurred in the same area – the Bay of Campeche, Mexico – in 1867.

When the tropical depression entered the Gulf, it offered “a little vorticity, a measure of rotation” to a storm system there, said Chris Slocum, a physical scientist at the National Oceanic and Atmospheric Administration's Center for Satellite Applications.

So, Milton organized himself and moved away from other systems.

“It is the isolation from other storms that allows the depression to deepen and winds to develop,” Slocum said. Milton began drawing air into its center and extracting energy from the warm ocean.

Small but powerful

Milton began as an extremely small storm, allowing it to conserve its angular momentum by spinning strongly and quickly around a narrow eye.

In the Gulf region, record ocean temperatures and warm, humid air were recorded – the necessary ingredients for intensification. On Monday, the central pressure rate in Milton's core fell A scientist is described as “crazy”. Milton grew stronger. Central pressure values ​​are closely related to storm strength and wind speed.

“It’s just scary,” said NBC South Florida hurricane expert John Morales. The air is suffocating as he discusses the importance of reducing stress.

Milton's winds increased to 92 mph in about 24 hours, according to the Climate Center, a nonprofit research group. It surpassed the milestone of what scientists consider to be rapid intensification: Gain of 35 mph in 24 hours.

“It went from a tropical storm to a Category 5 hurricane in less than two days, which is out of the question,” said Karthik Balaguru, a climate scientist at the Pacific Northwest National Laboratory.

Jonathan Lynn, an atmospheric scientist at Cornell University who forecasts and models hurricanes, called Milton “one of the most rapidly intensifying hurricanes we have ever seen in the Atlantic.”

The hurricane's winds — which exceeded 175 miles per hour — were unprecedented for an October storm. Milton is the strongest hurricane in the Gulf of Mexico since Hurricane Rita in 2005.

A new eyewall

In the Northern Hemisphere, hurricanes spiral counterclockwise around a nearly cloudless eye at their center.

During the night of Monday and Tuesday, a band of rain formed on the outskirts of Milton. These storms converged and formed a second ring, creating a replacement eyewall and tripling the radius where maximum wind speeds were recorded, Slocum said.

This phenomenon, known as eyewall replacement, generally increases the storm's amplitude but loses some wind speed, as happened in Milton. This can happen several times as the storm develops. Once the process is complete, the hurricane may begin to gain intensity again, if conditions allow.

“You can think of it as shedding skin. After shedding the skin, it may become inflamed again. That’s exactly what we saw with Milton,” Lynn said.

An oscillation

According to the National Hurricane Center, Milton changed its projected path and shifted its estimated landfall south on Tuesday afternoon, “dominating.”

Oscillation results from complex dynamics within the eyewall.

Lynn explained the dynamics by comparing the hurricane to a spinning top or spinning top.

“Sometimes you’ll see a top – you push it a little, give it a poke and it moves a little and then it starts spinning again,” Lynn said. “It rebuilds itself.”

A significant jolt can change the path of a storm and determine where the hurricane will impact.

As much as forecasters expect 13-foot storm surge. If the storm moves slightly south, it could keep the worst of the flooding out of Tampa Bay, which is particularly vulnerable. Hurricane Irma moved east in 2017, which helped keep Tampa Bay at bay. Have a projected storm surge of 12 feet or more.

As the storm approaches the coast, areas south of Milton's eye are expected to receive strong winds that will push water toward the coast – and the resulting storm surge.