The active part of hurricane season may extend deep into fall this year with a tropical-cyclone friendly La Niña delayed but still expected.
A forecast released Thursday, Aug. 8, by the Climate Prediction Center pushed back the likely onset of La Niña, which was favored to rise this month, until sometime in September through November.
The center, part of the National Oceanic and Atmospheric Administration, said atmospheric conditions remain in limbo for now and may stay that way for at least another month.
Matt Rosencrans, the lead hurricane seasonal forecaster for NOAA, said La Niña, however tardy, most likely means a lingering period of tropical trouble later into the year.
“Whereas in a typical year, activity tends to taper off in October, our team at the Climate Prediction Center expects that the tropics will remain active through October, possibly into November,” said NOAA public affairs specialist Erica Grow Cei in an email.
Hurricane season runs June 1 through Nov. 30. The peak of hurricane season is pegged at about Sept. 10 with activity picking up in August and starting to wane in early October.
La Niña and its climate sibling El Niño are part of the powerful El Niño Southern Oscillation, or ENSO. The neutral phase of ENSO is currently in place, meaning weather, water temperatures and winds in the equatorial Pacific Ocean are about average.
The delay in La Niña is a change from predictions made earlier this year that favored its debut during the summer.
2024 Hurricane Season Guide:Storm preparation tips, supplies, evacuation zones, insurance info
When La Niña is in place, there is less storm-killing wind shear in the Atlantic Ocean, allowing budding cyclones a better footing to get started. El Niño increases wind shear, which can cut the tops off developing storms and lead to less tropical activity.
A pokey La Niña doesn’t mean the rest of hurricane season will be sluggish.
Thursday’s ENSO forecast came out the same day as NOAA’s updated hurricane prediction, which continues to call for a highly active season with 17 to 24 named storms, including eight to 13 hurricanes. Of the hurricanes, four to seven could be major hurricanes of Category 3 or higher.
An average hurricane season has 14 named storms, seven hurricanes and three major hurricanes
NOAA’s forecast includes hurricanes Beryl and Debby and tropical storms Alberto and Chris.
Colorado State University also issued its updated forecast this week that calls for 23 named storms, down from a July forecast of 25, including 12 hurricanes. Of the 12 hurricanes, six are forecast to be major storms of Category 3 strength or higher.
An average hurricane season has 14 named storms, seven hurricanes and three major hurricanes.
“Climatologically, the season in the Atlantic doesn’t really get going until August in a normal year,” said Chris Davis, senior scientist at the National Science Foundation National Center for Atmospheric Research. “Most hurricane activity is in August and September and a little bit into October so we still have most of the season to go.”
On Friday, the National Hurricane Center was still forecasting long-lived Debby and watching a tropical wave west of the Lesser Antilles with a 50% chance of development over the next seven days. The next name on the 2024 hurricane list is Ernesto, followed by Francine.
In an average year, the fourth named storm forms Aug. 15 with the second hurricane forming Aug. 26. This year is ahead of the curve on both counts with the fourth named storm, Debby, gaining hurricane strength late on Aug. 4.
It’s not unprecedented for hurricane seasons to drag into November or even December.
Hurricane Nicole in 2022 made landfall Nov. 10 south of Vero Beach as a Category 1 storm.
Were you hear for the Mean Season?:Two decades later, 2004 is remembered as the 'mean season' as hurricanes shredded Florida
In 2020, four major hurricanes of Category 3 or higher formed in October and November, including Hurricane Iota, which reached Category 5 stature.
The 2005 hurricane season also stretched deep into winter and even jumped into 2006 with Tropical Storm Zeta, finally calling it quits Jan. 6.
Emily Becker, associate director of the University of Miami’s Cooperative Institute for Marine and Atmospheric Studies, said she’s not surprised that La Niña is not following the forecast from earlier this year.
“A small change in the winds can have a big effect this time of year, and small changes like that on the weather timescale are unpredictable far in advance,” Becker said. “It will be more surprising if La Niña fails to develop at all.”
Kimberly Miller is a journalist for The Palm Beach Post, part of the USA Today Network of Florida. She coversreal estate and how growth affects South Florida's environment. Subscribe to The Dirt for a weekly real estate roundup. If you have news tips, please send them to kmiller@pbpost.com.Help support our local journalism; subscribe today.
