Bata is being actively torn apart by wind shear, the “calling card” of El Niño’s influence on the Atlantic hurricane season. But don’t thank El Niño just yet.
Why Tropical Storm Vata still threatens the Gulf Coast
Despite its low strength, Tropical Storm Bertha poses a risk of flooding, heat, and rip currents to Louisiana, Texas, and Mississippi.
July 22: As Tropical Storm Vata continues to rotate along the Gulf Coast, strong upper-level winds are tearing through the system, leaving it much weaker than normal.
The upper-level winds known as wind shear plaguing Vata could be a harbinger of what to expect for the rest of the 2026 Atlantic hurricane season, which is expected to be heavily influenced by a strong El Niño.
Michael Rowley, a Miami-based WPLG-TV hurricane expert, told CNN that wind shear is “El Niño’s biggest calling card.”
Lowry said the most notable feature of El Niño during the hurricane season is the gradual rise in vertical wind shear, a scissor-like wind pattern that cuts off the top of an organized storm’s seedlings before it develops into a strong hurricane.
However, these particular winds in the Gulf are not directly related to El Niño. And there is some evidence that this particular weather pattern is not directly related.
El Niño tends to affect the Caribbean and tropical Atlantic winds, but not necessarily the Gulf Coast.
“I think it’s a little difficult to link the stronger shear that Virta is currently experiencing to El Niño,” Colorado State University hurricane researcher Phil Klotzbach said in an email to USA TODAY. “That’s because El Niño tends to have the strongest shear shocks at lower latitudes, such as the Caribbean Sea and the tropical Atlantic Ocean.
“The strong shear that Bertha is currently experiencing is caused by high pressure over the Midwest,” he said. “The circulation around that high pressure system is causing a strong northeastward shear over Virta.”
What is wind shear?
CNN meteorologist Mary Gilbert said in an online report that wind shear refers to changes in wind direction and speed between different levels of the atmosphere.
“It has the potential to tear apart tropical systems or prevent them from forming in the first place, and it is establishing a firm grip on the Caribbean Sea and the western Atlantic Ocean,” Gilbert said earlier this week. “June and July are usually the quietest months of the season, but this shear is causing a major disturbance and could even affect the busy season,” she added.
Where does El Niño fit in?
How does El Niño, the natural warming of ocean waters in the tropical Pacific Ocean, cause wind shear in the Atlantic Ocean?According to the National Oceanic and Atmospheric Administration (NOAA), El Niño first warms the Pacific Ocean, changing global atmospheric circulation patterns. These changes result in stronger winds and increased wind shear over the Caribbean Sea and the tropical Atlantic Ocean.
According to NOAA, hurricanes occur when the atmosphere is relatively calm from the surface to the upper levels.
Strong wind shear tilts the early storm, destroying its core and preventing the upward transport of heat and moisture that fuel tropical cyclones and hurricanes. As a result, ongoing tropical disturbances are more likely to weaken, disorganize, or have a harder time intensifying into major hurricanes due to El Niño’s wind shear, NOAA reports.
El Niño’s impact is earlier than usual
But it usually takes some time for abnormal warming of ocean waters in the eastern Pacific Ocean (the ocean phenomenon that defines El Niño) to connect weapons and the atmosphere, changing global circulation patterns and ultimately changing the shape of tropical Atlantic winds, Lowry said.
“However, this year we appear to be seeing the atmospheric effects of El Niño strengthening earlier than usual, which may be the result of record warming in the eastern equatorial Pacific,” Lowry said in an email to USA TODAY.
The increase in wind shear is greatest in the western tropical Atlantic, particularly across the Caribbean, which also helps reduce the number of landfalls in the United States in El Niño years.
A quiet season is expected due to El Niño.
The forecast for the 2026 Atlantic hurricane season is mostly below normal due to El Niño storms. For example, Colorado State University said in a recent forecast that only nine named storms will form, far below the average of 14.
What’s next for hurricane season?
Klotzbach added that he predicted that continued strong wind shear over the Caribbean Sea and Atlantic Ocean will likely continue to subside before the hurricane develops.
“Vertical wind shear is now even higher than typically seen in a below-average Atlantic hurricane season,” he said. “As you would expect given the ongoing strong El Niño, the latest four-week forecast from[European weather model]ECMWF indicates that significant above-normal shear is likely to occur in the Caribbean and tropical Atlantic over the coming weeks.”
Doyle Rice is a national correspondent for USA TODAY, focusing on weather and climate.
