The 2014 Atlantic hurricane season, which ended Sunday, extended Florida’s increasingly remarkable run: For the ninth consecutive year, the longest stretch on record, not a single hurricane struck the state.
It’s the kind of lucky streak residents love and forecasters fear.
Forecasters fret about growing public complacency. Because when it comes to hurricanes in Florida, calm never lasts. The longest previous respite lasted only five seasons, from 1980 to 1984.
“I would love to set another record next year … but that is not realistic,” said National Hurricane Center spokesman Dennis Feltgen. “This remarkable streak will come to an end, and we have to be prepared that it could happen in 2015.”
The 2014 season also marked the second year that the Atlantic has remained relatively quiet, said Gerry Bell, lead hurricane forecaster for the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
That raises the question of whether the tropics are finally easing into a less-active cycle after nearly a decade of pumping out some of the busiest seasons on record, including an all-time high of 28 named storms in 2005. Florida was pummeled repeatedly in 2004 and 2005.
“Is it possible we’re coming out of this high-activity period? I don’t know,” Bell said. But the 2014 season, he said, could provide clues that he’ll be looking at.
He also cautioned that “even if the overall season is suppressed, you can get a major hurricane if conditions are conducive for even a week.” Andrew is the scariest example.
The monster Category 5 storm of 1992 occurred in a year that produced just seven storms and only one hurricane — Andrew. But that one storm killed 44 people, destroyed 63,000 homes and caused $25 billion in damage in Florida alone.
By contrast, the 2014 season wrapped up with eight named storms. Six became hurricanes. Only one, Gonzalo, grew to a Category 4 storm — the first in the Atlantic since 2011 — but it remained far from the U.S. coast.
In May, forecasters had predicted a slow season of eight to 13 storms, with three to six becoming hurricanes and only one or two strengthening to a major storm with winds stronger than 111 mph.
But forecasters were nervous coming off a 2013 prediction that overshot the season: they had predicted an active season with up to 20 named storms, between seven and 11 hurricanes, and up to six major hurricanes. But that year produced just 13 named storms. Only two, Humberto and Ingrid, became hurricanes — although Ingrid, along with Tropical Storm Manuel, were blamed for 192 deaths in Mexico and damage estimated at $5.7 billion.
William Gray, the Colorado State University climatologist who pioneered preseason forecasts, called 2013 a bust, blaming the botched forecast on the collapse of a deep current called the Thermohaline Circulation. The current can carry denser, saltier water from the Earth’s polar oceans and help fuel hurricanes.
“Last year was just a really tough forecast. It wasn’t just us. Everybody busted badly. And this year everyone did really well,” said Philip Klotzbach, who works with Gray at the university’s Tropical Meteorology Project.
This season got off to a boisterous start with Arthur, the first named storm, which strengthened to a hurricane as it glided up the U.S. coast. By the time it made landfall, dashing Fourth of July celebrations in North Carolina, it had strengthened to a Category 2.
On Aug. 1, Hurricane Bertha crossed the Lesser Antilles as a sloppy, disorganized storm, but grew as it trekked across the ocean and hit western Europe with winds of more than 100 mph, triggering widespread flooding.
In late August, Hurricane Cristobal sprung up and slammed Hispaniola, where four people drowned. Cristobal was blamed for another drowning in the Turks and Caicos as well as two more off New Jersey and Maryland, where swimmers were lost to rip currents. Dolly made landfall in Mexico as a tropical storm, but quickly fizzled in early September. Within a week, Edouard formed and grew to a Category 3 hurricane. The storm remained far from shore, but it will be remembered for being the first into which NOAA deployed unmanned drones.
Fay followed, growing to a minimal Category 1 storm and causing a mess in Bermuda, downing power lines and trees and triggered flooding. Just as the island was cleaning up, Gonzalo struck. The season’s biggest storm, Gonzalo grew to a Category 4, but weakened to a Category 2 by the time it reached Bermuda. Hanna was the last tropical storm of the season, soaking Nicaragua and Honduras in late October.
The reason for the slow season stems primarily from strong winds in the upper atmosphere that can pull apart a storm, Klotzbach said.
“When you have that, you basically have a tug-of-war on the storm,” Klotzbach said. “It doesn’t like to be pulled in one direction and, higher up, tugged in another.”
The monsoon season off West Africa, where Atlantic hurricanes are born, was also mild, as expected.
Those dominant climate patterns are typically what forecasters rely on to predict a season. Another factor that regularly drives hurricanes in the Atlantic is the El Niño pattern, a band of warm water that develops in the Pacific and can influence air pressure over the ocean. Early in the season, forecasters expected an El Niño to occur and help tamp down Atlantic storms. The pattern never developed, but the strong winds in the Atlantic’s upper atmosphere turned out to be enough.
This year’s forecast was also aided by increasingly sharp computer modeling, Bell said. In the past five years, modeling has improved dramatically with higher-powered computers.
“They predict key things like wind shear,” he said, referring to the upper- and lower-level winds that can tug apart a storm. They also produce finer details about atmospheric pressure, another crucial ingredient in a storm. Still, the models take time, and still don’t work well enough to predict rapid intensification.
“Predicting these periods of rapid intensification is really a challenge,” Bell said. “How do you say yesterday it’s going to intensify in a day and a half? They want to be able to do that with much more lead time so they can alert people much better.”