Why South Florida is getting such severe weather, tornado threats

Meteorologists began warning even before the end of hurricane season that this year’s brawny El Nino – one of the most potent on record – could spur violent tornadoes in Florida.

The storms that tore across the state this morning were moving near 50 mph as part of a cold front heading in from the the Gulf of Mexico.

It was the second such set of storms in the past week as South Florida was also lashed by winds and rain, with threats of tornadoes, on Friday.

“This storm rapidly intensified over the Gulf of Mexico during Saturday night and pushed heavy, gusty thunderstorms across Florida,” AccuWeather Senior Meteorologist Michael LeSeney said.

Tornado aftermath in Sarasota, Jan. 17, 2016. Photo by Mark Killian, @KillianPhoto

Tornado aftermath in Sarasota, Jan. 17, 2016. Photo by Mark Killian, @KillianPhoto

Tornadoes have touched down across portions of Florida during Saturday night, including Siesta Key. A wind gust of 82 mph was recorded at Naples.

According to the National Weather Service, a gust of 40 mph was recorded just before 7 a.m. today at Palm Beach International Airport.

In the seven most formidable El Nino years since 1957, 178 tornadoes formed in Florida.


The monster El Nino of 1997-98 contributed to deadly tornadoes in the Sunshine State, killing 42 people and injuring 365, according to the National Climatic Data Center.

“Stronger and longer track tornadoes are more frequent during El Nino,” said David Zierden, Florida’s state climatologist. “The frequency of EF-1 tornadoes or greater is more than twice as likely during a strong El Nino.”

An EF-1 tornado has winds of between 86 mph and 110 mph.

The so-called “Groundhog Day tornado,” which occurred on Feb. 2, 1998, rampaged 21 miles from the Miami International Airport to southern Broward County. It caused $205 million in damage and left hundreds of thousands without power.

In the six strongest El Nino years since 1950, the number of dry season EF-1 or greater tornadoes in South Florida was more than double the average of all El Ninos. An Ef-1 tornado has winds from 86 mph to 110 mph.

Most tornadoes occur in February or March, but there’s no trend in what time of day they spin up.

Looking west from downtown West Palm Beach on Friday as strong storms moved through. Photo by Eddie Ritz

Looking west from downtown West Palm Beach on Friday as strong storms moved through. Photo by Eddie Ritz

In 1983, also a strong El Nino year, a tornado spun up west of the Everglades, traveling 53 miles before exiting near Pompano Beach. It caused $2.5 million in damage.

“When we have this El Nino pattern, we have a wintertime tornado season that develops and sometimes we can see some pretty violent tornadoes,” said Robert Garcia, a National Weather Service meteorologist in the Tampa office, which covers Cape Coral.

The system that hit Cape Coral earlier this month can be linked to the one that went through California three days earlier. During El Nino years, storms can move in from the warmed Pacific Ocean and embed themselves in the subtropical jet stream, which gets pushed north across the Gulf of Mexico.

During the early part of last Saturday a warm front that preceded a low pressure system came through southwest Florida. The warm moist air rose into the atmosphere, causing pressures to fall, thunderstorms to form and air columns to spin.


Kelly Anderson told The News-Press (http://tinyurl.com/jukunml) Saturday’s storm started out as a windy evening and then suddenly everything started to rattle and shake so she sought cover in the bathroom.

“Within minutes everything let loose. I heard glass behind me shattering everywhere,” she said.

In winter, El Nino pumps energy into the subtropical jet stream, which increases storminess in Florida, but cuts down on freezing weather as the frigid winter air rushing down from Canada gets hung up north of the subtropical ridge.

The cooler weather associated with El Nino in Florida is more related to increased cloud cover than traditional arctic air blasts.

Zierden, Florida’s state climatologist, worries that Floridians are more aware of hurricanes than tornadoes, not realizing the risk, especially during a strong El Nino. Even during normal years, Florida can have as many as 66 tornadoes per year. It ranks third nationally for tornado activity, falling behind top-ranked Kansas and runner-up Texas.

In a NWS presentation from the Melbourne office about the winter season, meteorologists stressed that millions of people moved to Florida since the deadly 1998 tornadoes.

“Floridians generally don’t perceive the threat of tornadoes as much as other parts of the country,” Zierden said. “But the whole peninsula has an enhanced risk of tornadoes during strong El Nino years.”

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