After the most ferocious hurricane season on record in 2020, top hurricane forecasters on Thursday said we should expect another active, above-normal season again this year.
For the season, which begins June 1, meteorologist Phil Klotzbach and other experts from Colorado State University – among the nation's top seasonal hurricane forecasters – predict 17 named tropical storms will form, eight of which will become hurricanes.
An average season has 12 tropical storms, six of which are hurricanes.
In 2020, there were a whopping 30 named storms, 13 of which were hurricanes.
If the prediction holds true, it will be the sixth consecutive above-normal season.
A tropical storm becomes a hurricane when its wind speed reaches 74 mph.
Of the eight predicted hurricanes, four are expected to spin into major hurricanes – Category 3, 4 or 5 – with sustained wind speeds of 111 mph or greater. The group said there's a 69% chance for at least one major hurricane to make landfall somewhere along the U.S. coastline.
The Atlantic hurricane season runs from June 1 to Nov. 30, though storms sometimes form outside those dates. In fact, storms have formed in May in each of the past six years.
Overall, the team predicts that 2020 hurricane activity will be about 140% of the average season.
No El Niño in 2021
Reasons for the active season include unusually warm seawater in portions of the Atlantic Ocean and also the lack of an El Niño.
One of the major determining factors in hurricane forecasting is whether we are in an El Niño or La Niña climate pattern.
El Niño is a natural warming of tropical Pacific Ocean water, which tends to suppress the development of Atlantic hurricanes. Its opposite, La Niña, marked by cooler ocean water, tends to increase hurricanes in the Atlantic.
"Reasons for above-average forecast include the predicted lack of El Nino," Klotzbach tweeted Thursday.
El Niño generally increases vertical wind shear in the Atlantic, tearing apart hurricanes.
Insurance companies, emergency managers and the media use these seasonal forecasts to prepare Americans for the year's hurricane threat. The team's annual predictions provide the best estimate of activity during the upcoming season, not an exact measure, according to Colorado State.
"We issue these forecasts to satisfy the curiosity of the general public and to bring attention to the hurricane problem," the university said. "There is a general interest in knowing what the odds are for an active or inactive season."
The university, under the direction of meteorologist William Gray, was the first group to predict seasonal hurricane activity in the mid-1980s. Gray died in 2016.
This is the team's 38th forecast. It covers the Atlantic basin, which includes the Caribbean Sea and the Gulf of Mexico.
AccuWeather released its hurricane forecast for the upcoming season last week, predicting that 16 to 20 named storms would form, of which seven to 10 will become hurricanes. The firm said three to five storms are likely to hit the U.S.
Federal forecasters from the National Oceanic and Atmospheric Administration will issue their prediction for the season in May.
The first named storm of the Atlantic hurricane season will be Ana, followed by Bill, Claudette, Danny, Elsa, Fred and Grace.
Colorado State forecasters will update their predictions three times over the next few months.