Every hurricane season, keen-eared storm preppers may hear a familiar Latin name: “El Niño.”
But what is El Niño? Is it good?
Is it bad?
Is it a character in a spaghetti western film?
In regard to the latter, yes, check out “A Bullet for the General” to get that reference.
In regard to the former questions, objectively speaking, it’s neither good nor bad, but its presence, or lack thereof, can influence whether or not Florida is at a higher risk of being caught in the wind of an incoming hurricane.
Spanish for “the little boy,” El Niño is a phase of the El Niño-Southern Oscillation cycle, according to the National Oceanic and Atmospheric Administration. The ENSO cycle describes the changes in temperature between the ocean and atmosphere in the east-central Equatorial Pacific. An ENSO cycle is made up of three phases: a neutral phase, a warm phase (El Niño) and a cold phase (La Niña.)
The first credited discovery of El Niño dates back to the 1890s when Peruvian fishermen noticed currents would occasionally stop, warm water from the tropics would drive the fish away and leave their nets empty, according to the NOAA. The fishermen observed these periodic warm spells were most noticeable around December or January, or around Christmas time — around the birth of “the child,” giving the cycle its name.
Near the same time, a meteorologist, Gilbert Walker, was in India studying the Indian monsoon season, when he discovered that sea level pressures varied between the Indian and Pacific. He called this flow the “southern oscillation,” said NOAA climate scientist Michelle L’Heureux.
“It wasn’t until 50 years later, a man Jacob Bjerknes was able to put it all together,” L’Heureux said. “He took the Peruvian findings and Gilbert’s work and saw that these phenomenon augment each other and give rise and decay to ‘El Niño’ and ‘La Niña’.”
But how does warm water in the Pacific affect hurricanes in the Atlantic?
Well, scientists agree what happens in one ocean has a big effect in the other.
If El Niño has a strong presence, or makes Pacific waters warmer than usual, it increases the amount of “wind shear” across the the Atlantic basin. Wind shear is bad for hurricanes, and tropical storm production. It disrupts necessary conditions for tropical storms to form. If La Niña is cooling Pacific waters, this influences the Atlantic atmosphere by reducing vertical wind shearing.
To be clear, the ENSO cycle is not the only factor meteorologists look at when creating hurricane forecasts. Predicting hurricanes is a akin to putting together a jigsaw puzzle — there’s a lot of pieces to consider in creating the bigger picture.
“ENSO is probably the most important puzzle piece when predicting precipitation,” L’Heureux said. “It offers predictability. It forces the atmosphere into configurations and we can make predictions on that.”
Those predictions are extremely relevant such as the last hurricane season.
Meteorologists predicted a weak El Niño and a strong La Niña for 2020, which led to the NOAA giving the largest prediction in tropical storm production it had ever made; predicting between 19 and 25 named storms. A typical season has 12 named storms and six hurricanes. The 2020 season had 30 named storms, 13 of which were hurricanes.
The 2020 season is still being reviewed by experts, but L’Heureux said that the ENSO cycle more than likely played a big contribution to the record breaking year.
“We saw a huge atmospheric teleconnective footprint (to ENSO),” she said. “It would be more surprising to find out that it didn’t play a large contributing factor.”
ENSO’s great predictability is why meteorologist keep monthly tabs on it, although ENSO prediction changes frequently until summer, L’Heureux said.
However, just because El Niño conditions are present, doesn’t mean hurricanes can’t form and hit Florida.
Actually it’s happened at least 10 times since 1953, according to the National Hurricane Center’s records.
In the last 30 years, five hurricanes have made landfall in Florida while El Niño conditions were present. Four of them were notorious storms, too: 2004’s hurricanes Charley, Frances and Jeanne; as well as 2018’s Hurricane Michael. Other factors may have played a part in producing such storms.
Got a hurricane question? Send them to jpedersen@orlandosentinel.com.
