Another busy Atlantic hurricane season is expected, government forecasters say
Over the last two seasons, 18 tropical cyclones have landed on U.S. shore, a two-year record.
In a forecast about as welcome as another gas-price increase, government hurricane specialists Tuesday added to the growing consensus that once again this could be an active Atlantic tropical-storm season.
Odds strongly favor above-average storm numbers for a seventh consecutive year, said meteorologists at the government’s Climate Prediction Center, with 14 to 21 named storms, those with winds of at least 39 mph; six to 10 hurricanes, with minimum top winds of 74 mph; and three to six major hurricanes, with peak winds of 111 mph or higher.
The long-term averages for the Atlantic Basin, which includes the Caribbean Sea and Gulf of Mexico, are 14 named storms and seven hurricanes, with three of those becoming major.
» READ MORE: Philadelphia has felt the fallout from the hurricane uptick, Ida being the extreme example
The government outlook tracks closely with those already issued by major forecasting services, including AccuWeather Inc., WeatherBELL Analytics, Colorado State University, and the European Union’s forecast center.
“There’s definitely good agreement,” said Colorado State’s Philip Klotzbach.
And although it isn’t an indicator of what’s to come, he said, this season isn’t off to a precocious start. For the first time in eight years, it appears that no named storms will form before the June 1 official beginning of the Atlantic season.
The tropical-storm numbers have not only been off the charts the last two seasons; a total of 18 of them have landed on U.S. shores, which was a two-year record. The previous two-year record was six, set in 1851.
Philadelphia in the last two seasons has been affected significantly by six tropical storms or their remnants, including Ida and three others in 2021.
None of the outlooks address landfalls specifically, just the broader trends that speak to the potential numbers.
As have the other forecasters, the meteorologists at the climate center, a division of NOAA, cited above-normal sea-surface temperatures in the subtropical Atlantic, which would provide fuel for potential cyclones, and cooler waters in the Pacific, which is in an ongoing state of La Niña.
» READ MORE: Here's how La Nina can affect hurricanes in the Atlantic
During La Niña, the west-to-east winds that can sheer off incipient storms in the Atlantic Basin are weakened. The climate center sees a near 60% chance that La Niña persists through the tropical-storm season, said hurricane specialist Matthew Rosencrans,
As for what’s behind the uptick, climate change is definitely a suspect, NOAA says.
Satellites and other advances in observation technology likely have been able to identify smaller, short-lived storms that previously would have gone undetected. Rosencrans said the advances “are likely responsible for about two named storms every year.”
But the warming is having impacts on tropical cyclones, Rosencrans added, increasing top wind speeds 2% to 11%, and rainfall by about 3% near storm centers, with models saying that eventually could increase to 7%.
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The Atlantic Basin entered into an “active” cycle in 1995, and historically, lull- and active-hurricane seasons have alternated in 25- to 40-year cycles.
Research continues into whether this active cycle will end — or has flipped into another mode of behavior.