2023 Atlantic hurricane season should be 'slightly below average,' Colorado State University researchers say

The Atlantic hurricane season starting June 1 should be “slightly below average,” Colorado State University researchers said on Thursday, as a possibly developing El Niño weather system could increase Caribbean winds that rip these storms apart.

The university, which has studied hurricanes for four decades, in a statement predicted 13 named storms during the hurricane season, which ends Nov. 30.

“Of those, researchers expect six to become hurricanes and two to reach major hurricane strength … with sustained winds of 111 miles per hour or greater,” the researchers said.

Last year's hurricane season had 16 named storms, nine of which were hurricanes, including Fiona, which hit Puerto Rico in mid-September, and Ian, which walloped Florida in late September.

The National Hurricane Center, part of the National Oceanic and Atmospheric Administration, is expected to issue its hurricane predictions on April 25.

'More uncertainty than normal'

The Colorado forecasters cautioned that when and whether a strong El Niño system develops complicates their analyses.

“Given the conflicting signals between a potentially robust El Niño and an anomalously warm tropical and subtropical Atlantic, the team stresses that there is more uncertainty than normal with this outlook," the forecasters said.

The unusual third La Niña in a row that increased Atlantic hurricane activity and worsened western drought has disappeared, NOAA said in March. La Niña might give way to neutral conditions — depriving meteorologists of one of their stronger, longer-term signals, it explained.

 Forecasters say any El Niño outlook remains unclear. For the moment, Jeff Masters, a Yale Climate Connections meteorologist and co-founder of Weather Underground, told Newsday: "The storm-nurturing effects of a warm Atlantic seem likely to be counterbalanced by a robust El Niño, and if one of these factors tilts the other way, the forecast could change significantly."

As the Colorado experts said: “Current large-scale conditions and forecasts indicate that a transition to El Niño is relatively likely in the next several months." 

La Niña and El Niño are opposites. 

La Niña forms when the equator’s easterly trade winds intensify, pushing the Pacific Ocean to Asia. The coldest sea levels then rise off Latin America's west coast.

Sweeping toward the U.S. West Coast, the jet streams let more hurricanes form, but they often blast up the Ohio Valley and the Great Lakes.

El Niño, by contrast, can curb storms, as it drives the jet stream much farther south, into northern Florida and the Gulf of Mexico, according to NOAA.

It arises when easterly trade winds weaken or even reverse. So less of the ocean’s bottom waters rise off the western South America coast. And that warmer water can, NOAA says, spill toward the eastern Pacific.

 Forecasting — though still not accurate beyond several days — has vastly improved with supercomputers sorting countless data but the Colorado team also looked at history — one of the main tools their predecessors had.

The probability of major hurricanes making landfall is:

• 44% for the entire U.S. coastline (average from 1880-2020 is 43%)
• 22% for the U.S. East Coast, including the Florida Peninsula (average from 1880-2020 is 21%)
• 28% for the Gulf Coast from the Florida panhandle westward to Brownsville (average from 1880-2020 is 27%)
• 49% for the Caribbean (average from 1880-2020 is 47%)