by Tim Smith
Prepare to batten down the hatches again – forecasters expect 2021 will be the sixth overactive hurricane season in a row.
Between 16 and 20 named storms have been predicted by AccuWeather, including seven to ten hurricanes, of which three to five are predicted to become Category 3 or higher.
It is likely to fall short of the record-breaking Atlantic hurricane season of 2020, which featured 30 named storms and 12 direct strikes on the United States as well as a direct hit on Bermuda, Hurricane Paulette in September.
But it is still forecast to beat the 30-year average of 14 named storms including seven hurricanes.
AccuWeather warned as early as March that sea-surface temperatures were above normal in the tropical Atlantic, much of the Caribbean and northern and central Gulf of Mexico.
A greater than normal number of tropical waves are also predicted to develop off the African coast this season as dry air and dust becomes less common from Africa.
However, there is some hope that the La Niña phenomenon in the Pacific, which helped increase hurricane activity last year, will not have as much impact this year.
Veteran meteorologist Dan Kottlowski said: “Current indications are this will be another above-normal season.”
The Bermuda high – a high-pressure area that helps to protect Bermuda – last year helped push some storms away from the Eastern Seaboard and into the Caribbean and the Gulf of Mexico.
AccuWeather predicts the Bermuda high will not maintain its strength so frequently this year, so storms will be more likely to recurve through the western Atlantic and threaten the East Coast.
Mr Kottlowski had warned that the season could begin earlier than its official start date of June 1, because of warm waters in the tropical breeding grounds of the Atlantic.
“Our biggest concern is the fact that water temperatures across the Atlantic are already warmer than normal over a larger part of the basin,” he said.
He added that it would not take much to make those water temperatures go even higher through the summer and into the peak of the season.
A team from the University of Arizona in April predicted 18 named storms, including eight hurricanes, by using a computer model combining forecasts of sea surface temperature, wind, pressure, humidity and precipitation with their knowledge of hurricane formation and artificial intelligence.
Xubin Zeng, the forecast creator who led the team, said the trend of above-average hurricane seasons should be taken seriously.
He said: “The past decade has been very active for hurricanes.
“We need to ask ourselves if this is part of the natural variability of the system, or if we are already seeing impacts of global warming. If this is part of the natural variability, then after some overactive seasons, we’d expect activity to quiet down, but every year is kind of crazy in the past few years.”
Researchers at Colorado State University have forecasted 17 named storms, including eight hurricanes, of which four are major.
They said the 2021 hurricane season is showing characteristics similar to 1996, 2001, 2008, 2011 and 2017.
Phil Klotzbach, the research scientist who led the report, said: “All of our analogue seasons had above-average Atlantic hurricane activity, with 1996 and 2017 being extremely active seasons.”
North Carolina State University has predicted 15 to 18 named storms, of which seven to nine may become hurricanes, including two to three major hurricanes.
The Weather Company has predicted 18 named storms, of which eight are hurricanes, including three major hurricanes.
