Surprisingly robust storms create two tornadoes, gustnado

A familiar afternoon sea breeze and a middling cold front from the north collided like medieval armies Tuesday, loosing a riot of weather on South Florida that included two tornadoes and a less fearsome gustnado.

The storms, which were not expected to be so robust, focused largely in Broward County where Fort Lauderdale had EF-0 twisters zip through downtown and the airport with winds spinning

at an estimated 65 mph.

While the tornadoes were on the weak side, they were peppy enough to toss around portable bathrooms and flip cargo containers at Port Everglades. The downtown tornado pushed over trashcans, broke tree limbs

and knocked down construction barriers.

“It’s very common to get big sloppy gobs of rain from these storms, but they don’t typically get so well organized here as they did (Tuesday),” said Brian McNoldy, a senior research associate at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. “These were basically waterspouts that were not quite over water.”

A delay in the advancing front, or a hastening of its pace, may have dulled the atmosphere’s tornadic ambition. Instead, the front arrived just in time to clash with South Florida’s native sea breeze, twisting at the impact zone.

“It was a collision of air masses that creates an unstable enough

Palm Beach County was under a marginal threat for severe weather Tuesday — the lowest risk level on a severe weather scale used by the Storm Prediction Center. Broward County had no severe weather risk, but was forecast to have thunderstorms with lightning and possibly small hail.

atmosphere near the ground to get these very rapid spin-ups,” said Robert Molleda, the warning coordination meteorologist at the National Weather Service in Miami. “They don’t originate at the cloud level like you would see with a traditional super cell.”

That’s one reason why forecasting the type of weak tornadoes that spun up Tuesday is more difficult.

Palm Beach County was under a marginal threat for severe weather Tuesday — the lowest risk level on a severe weather scale used by the Storm Prediction Center. Broward County had no severe weather risk, but was forecast to have thunderstorms with lightning and possibly small hail.

“These tornadoes tend to be much more localized and very brief,” Molleda said. “The signals in the atmosphere aren’t quite as easy to pick out.”

In Palm Beach County, a social media post of a spinning air mass near Lion Country Safari was preliminarily identified by the National Weather Service as a tornado. Further review Wednesday morning revealed it to be a milder twister called a gustnado.

A gustnado forms at ground level along the leading edge of a pool of rain-cooled air that has spilled ahead of a thunderstorm’s down burst . As it moves ahead, it is accompanied by rapidly increasing winds that can begin rotating.

But unlike a tornado, which is connected from the surface to the storm above, a gustnado stays shallow, and quickly tires.

The gustnado was seen in an open field near 20-Mile Bend and southwest of Lion Country Safari.

Jennifer Berthiaume, managing director of Lion Country Safari, likened Tuesday’s storms to the “Wizard of Oz” with the sun lost behind black clouds, sideways blowing rain, and what she thought might be a tornado.

“It was heavier than a typical thunderstorm,” said Berthiaume, noting that no animals were injured.

More than two inches of rain fell in some areas of South Palm Beach County. That’ s more in 24 hours than the entire month of March. Much of the county got just .53 inches of rain last month — three inches below normal.

It’s unknown how Tuesday’ s rain affected the moderate drought that was reported last week in Palm Beach County by the U.S. Drought Monitor. The data for the report, which is released on Thursdays, is gathered through 8 a.m. Tuesday.

At Lion Country Safari, the storms damaged trees, pushed a lifeguard stand on top of water slides, blew a plexiglass windshield off a golf cart, and cut power for about fifive hours.

The only electrified fencing at the park is for the lions. It quickly transfers to a backup generator when the power fails.

“I immediately went on Twitter to see if there was a tornado,” Berthiaume said. “I was a little surprised there was no report.”

Despite the challenges of no electricity, Lion Country Safari remained open.

“Believe it or not, we had guests show up right after the storm was done,” Berthiaume said. “We gave them a signifificant discount.”