It’s a message storm-weary residents don’t want to hear: This active, record-breaking hurricane season is far from over.
After two back-to-back, catastrophic cyclones, with people in Florida and Houston just beginning to put their lives back together, it’s tempting to figure Mother Nature will show some mercy, at least until next year.
Not so, forecasters say. The conditions that spawned hurricanes Irma and Harvey are firmly in place and will be for weeks.
“There’s still a long way to go this season,” said Gerry Bell, lead forecaster for the National Oceanic and Atmospheric Administration’s Climate Prediction Center. “That’s what people need to hear because they need to make sure they stay prepared. There are going to be more storms, and that means more storms are going to threaten.”
The hurricane season, which runs from June 1 to Nov. 30, peaks in the months of August, September and October. Early September is the peak of the peak, but when conditions are ripe, there is more storm activity through October, Bell said.
Last month, Bell and his team updated their annual prediction for the 2017 Atlantic season to 14 to 19 named storms, of which five to nine could become hurricanes. Of those, the Climate Prediction Center estimated, two would become major hurricanes.
With the formation of Hurricane Jose, currently swirling in the Atlantic Ocean southwest of Bermuda, this season has already created 11 named storms, including six hurricanes, three of them major.
Colorado State University’s Tropical Meteorology Project updated its Atlantic forecast for the last time in August, calling for 16 named storms and eight hurricanes, three of them major.
Just because this season has already reached the predicted number of major hurricanes doesn’t mean there won’t be more, said Phil Klotzbach, a meteorologist at Colorado State University who helps put together the seasonal hurricane forecast.
In previous active seasons like 2004 and 2005, storms continued to form well into October, Klotzbach noted.
“If I could go back, I’d probably up the forecast a bit,” he said. “The conditions have been so conducive, you don’t just expect them to just turn off.”
Those conditions extend from Africa to the Gulf of Mexico.
For one, favorable winds coming off the west African coast strengthen cloud systems into tropical storms and hurricanes. Forecasters predicted that these winds would be stronger than average, and they have been, Bell said.
Another factor is wind shear, or changes in wind direction and speed at different levels of the atmosphere. Areas of low wind shear allows storm systems to turn clockwise from sea level to about 50,000 feet into the atmosphere, which helps keep storms intact and allows them to strengthen by drawing warm and moist air from the ocean.
In so-called El Niño years, when water temperatures in an area of the Pacific Ocean are higher than average, wind patterns are aligned in a way that increases wind shear over the Caribbean and Atlantic. This year, a lack of El Niño conditions helped storms like Irma and Harvey strengthen into the monsters they became, Bell said.
Those storms marked the first time two Category 4 storms made landfall in the United States in one year.
Generally, storms form in the Atlantic earlier in the season, as Irma did. By October, storms tend to emerge in the Caribbean.
“If you’re going to get something nasty, especially for Florida, that’s usually where it comes from,” Klotzbach said.
Exhibit A, said Klotzbach: the infamous 1921 hurricane that devastated the Tampa Bay area. It formed in the Caribbean on Oct. 20, “shot the gap” between Cuba and the Yucatan Peninsula and curved into the Gulf of Mexico. The unnamed storm made landfall near Tarpon Springs as a Category 3 on the modern day Saffir–Simpson hurricane scale, with sustained winds of at least 111 miles per hour.
The tropical storm that would become Hurricane Wilma, the 2005 formation that caused widespread destruction when it made landfall in South Florida, formed in the Caribbean on Oct. 17 of that year.
For now, at least, there appears to be a lull in the tropics.
Hurricane Jose had weakened to a Category 1 storm and was expected to loop around on its own path before turning to the north. Forecasters said Tuesday that a landfall on the U.S. East Coast appeared unlikely.
But as Florida residents clean up after Irma and pray for the power to come back on, they also need to stay vigilant.
“Don’t let your guard down,” Bell said. “It’s part of your responsibility of being a coastal resident to make sure you’re prepared.”
Contact Tony Marrero at firstname.lastname@example.org or (813) 226-3374. Follow @tmarrerotimes.