August is here, and that usually means it’s time for the hurricane season to ramp up.
“While we’re about one-third of the way done with the season, we’ve got about 95% of seasonal activity to go from an historical perspective,” Colorado State University hurricane researcher Phil Klotzbach told USA TODAY.
In fact, according to AccuWeather, the three most active months for hurricanes in the Atlantic are August, September and October. Hurricane season lasts from June through November.
This season, most forecasters – including Klotzbach’s team at Colorado State – have been confident of an unusually busy season. Specifically, earlier in July, the CSU team called for a “borderline hyperactive” season in the Atlantic Basin in 2023, with as many as nine hurricanes expected to form.
The upgrade was primarily attributed to extremely warm ocean water in the Atlantic where storms like to form, forecasters said. The unusually warm Atlantic was expected to battle with, and possibly counteract, the hurricane-snuffing influence of El Niño.
Busy start to Atlantic hurricane season 2023, but no big storms have threatened US
It has been a rather busy first two months of the season, experts said: There have been five storms and one hurricane through the end of July, Weather.com reported. (That includes an unnamed subtropical storm in January.)
That’s the fourth most-active start of any season since 1851, Weather.com meteorologist Chris Dolce said.
No significant tropical storms or hurricanes have threatened the U.S.
Overall, June was a busy month (for June) with three named storms, Klotzbach said. The first in June was Arlene, which formed in the Gulf of Mexico and brought rain to South Florida.
Two of the storms formed in the “main development region” (Bret and Cindy), which is unusual for June. That region is a portion of the Atlantic where many of the biggest storms typically form, especially during the peak of the season. Neither Bret nor Cindy had any impact on the U.S.
July was a quieter month, with just one named storm forming: Don, which was briefly a hurricane in the open Atlantic.
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How could El Niño affect hurricane season 2023?
The El Niño climate pattern, a natural phenomenon marked by warmer-than-average sea water in the tropical Pacific Ocean, tends to reduce hurricane activity in the Atlantic. NOAA declared that El Nino had officially formed in June.
The reduction in hurricane activity happens because El Niño’s warmer waters make warmer air over the Pacific reach higher in the atmosphere, creating strong upper-level winds that can decapitate storms and kill them, Klotzbach said. It’s called wind shear.
But the full impact of El Niño hasn’t really started yet, Klotzbach told USA TODAY. He said that “at this point, we are seeing some El Niño-like signs, but it’s certainly not completely El Niño out there yet.” He said that the strong upper-level winds didn’t really kick in in July.
In addition, the higher atmospheric pressure El Niño usually produces in the Atlantic – which also acts to snuff out storms – was not present in July. “We haven’t really seen the classic El Niño response yet,” Klotzbach said.
In general, in El Niño years “we do see a weaker subtropical high in the Atlantic,” he added. “This weaker high pressure tends to allow for more frequent storm recurvature. That has been the trend so far this year, but it’s unclear if that will continue.”
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Warm ocean a wild card in August
Despite El Niño, much of the tropical Atlantic Basin continues to see record-warm ocean temperatures, Weather.com meteorologist Jonathan Erdman said. “That includes the main development region from Africa westward, in which many stronger Atlantic hurricanes get their start.”
That’s key because assuming other factors are equal, the deeper and warmer the ocean water, the stronger a storm or hurricane can become, Erdman said.
“This warmth we’re seeing right now is more typical of the peak of hurricane season, with time for additional warming.”
What’s next for hurricane season: Quiet start to August expected, then a possible uptick in activity
How does August look for storm activity?
“At this point, the next 10 days at least look pretty quiet,” Klotzbach said. “96L is really struggling at the moment, and if that doesn’t form, it’s looking unlikely we’ll see anything form through at least the first week in August.”
(96L is the name meteorologists gave to a developing system in the Atlantic.)
But as we get deeper into August, one model meteorologists use to forecast weather shows a possible increase in the ingredients necessary for storms to form.
Contributing: The Associated Press
