Tornado in Palm Beach Gardens a result of heat, humidity and tumult in upper atmosphere

The tornado twirled down from the clouds Saturday as if on a spindle, scouring the Earth for two minutes before phones blared warnings and a soupy mix of heat and humidity turned savage.

It was a volatile combination of speeding winds as high as commercial airplanes fly and rich hot air tugged up from the Caribbean that supercharged the cluster of thunderstorms over Palm Beach Gardens, two of which ultimately joined forces to foment 11 minutes of mayhem.

Meteorologists dissecting the ingredients that spawned Saturday’s EF-2 tornado said the atmosphere aloft was more winter-like than spring, with a river of strong frigid winds high in the atmosphere and a tropical balm at the surface where daytime temperatures Saturday hit 89 degrees in West Palm Beach — 5 degrees warmer than normal.

“It was a fairly violent set up for this time of year,” said Florida State University professor James Elsner, a severe weather expert in the school’s geography department. “It was producing tornadoes throughout the state but, obviously, in South Florida where you have had a lot more moisture, fast winds aloft give you the potential for damaging tornadoes.”

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There was severe weather statewide last week associated with the same set up that caused Saturday’s twister. The Storm Prediction Center logged hail — from showers of ice that overflowed rain gutters to pieces as large as golf balls — from the Georgia line through Palm Beach County on Wednesday.

Eight tornadoes were reported in the Florida Panhandle on Thursday. Boynton Beach was hit Friday with a weak EF-0 tornado and then Saturday saw two tornadoes including the one in Palm Beach Gardens and another in Charlotte County.

The EF, or Enhanced Fujita, label is similar to the hurricane categories that gauge strength and potential for destruction. It is named after Tetsuya Fujita, an engineer and meteorologist who developed the original version in the early 1970s. The EF scale goes from 0 to 5, with the EF-2 that struck Palm Beach Gardens ranked relatively strong in intensity with significant damage expected.

On average, Florida experiences four tornadoes in April and three in May, according to the National Oceanic and Atmospheric Administration. The busiest months for Florida tornadoes are June, with an average of seven, and September with eight.

Robert Molleda, warning coordination meteorologist with the National Weather Service in Miami, said Saturday’s unusual warmth and humidity sent hot air rushing high into the atmosphere. Towering clouds formed as the air cooled, sewing the seeds for thunderstorms.

At about 4 p.m., they began blistering in western parts of Palm Beach County heading east. An hour later, two thunderstorms merged between Florida’s Turnpike and I-95 in Palm Beach Gardens.

Together, they tapped into the chaos in the atmosphere, dropping a tornado that reached the ground at 5:10 p.m. near Palm Beach Gardens Elementary School.

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The tornado warning went out two minutes later.

“The wording of the alert struck me,” said Palm Beach Gardens resident Zach Means, who was trying to calm his storm-frightened dog Marlin by driving him around the area. “It said something like, ‘Seek shelter immediately,’ like, get out of the way, and I thought, we should go home.”

Means turned his car around to head south on U.S. 1 toward his apartment complex near PGA Boulevard. He was unknowingly heading right into the tornado’s path.

When the rain and wind got too heavy, Means said traffic stopped, and he started filming with his cell phone. Then his car was lifted and flipped over, landing in the northbound lanes. Marlin got tossed in the far back seat of his sport utility vehicle, but both he and the dog were OK.

"I think it was more than one roll," Means said. "The whole thing happened so fast it was hard to process."

Before reaching Means, the tornado skimmed south of Palm Beach Gardens Medical Center, uprooted trees in Sandalwood Estates, broke windows in in a home in the Rainwood community, crossed Burns Road, crossed Prosperity Farms Road, ripped bark from trees, destroyed a manufactured home, crossed PGA Boulevard, destroyed a dry cleaners business, toppled light posts and flipped two cars, including the one Means and Marlin were in, before dissipating south of Juno Beach at 5:21 p.m.

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It stayed on the ground for 2.61 miles. The width of its path was 320 yards at its maximum. Its top wind speeds were 130 mph.

“You have to be in the right position to get these kind of dynamics and we were in that quadrant,” said Todd Kimberlain, lead meteorologist for the South Florida Water Management District. “This is generally not what you see this time of year.”

Kimberlain said a particularly fast moving flow of air traveling along the jet stream called a "jet streak" contributed to the upper-level winds that stoked the supercell thunderstorms that formed Saturday. Supercells, which are the strongest types of thunderstorms, are marked by a counterclockwise spin in the air rushing into their updrafts.

They are also more organized and compact, giving them longer lifespans, Kimberlain said.

But not all supercells form tornadoes. Elsner compared a tornado forming to rolling up a carpet. The spinning winds start horizontal to the ground, but can be picked up and made vertical by very fast upward motion and wind shear within the thunderstorm.

"A tornado doesn't come out of the sky at EF-2 intensity," Elsner said. "But over the course of just a few minutes, it can really start to twist faster, and I would say Saturday's tornado was a fairly long-lived and long-tracked for Florida."

Kimberly Miller is a veteran journalist for The Palm Beach Post, part of the USA Today Network of Florida. She covers real estate and how growth affects South Florida's environment. Subscribe to The Dirt for a weekly real estate roundup. If you have news tips, please send them to kmiller@pbpost.com. Help support our local journalism, subscribe today. 

This article originally appeared on Palm Beach Post: Tornado EF2 in Palm Beach Gardens Florida ends week of severe weather