After the fiercest hurricane season on record in 2020, top hurricane forecasters said on Thursday we should expect another active, above-normal season this year.
For the season, which begins June 1, meteorologist Phil Klotzbach and other experts at Colorado State University – among the nation’s top seasonal hurricane forecasters – forecast 17 named tropical storms to form, including eight will become hurricanes.
An average season has 12 tropical storms, six of which are hurricanes. In 2020, there were 30 named storms, of which 13 were hurricanes.
If the prediction holds true, it will be the sixth straight season in a row above par.
A tropical storm becomes a hurricane when its wind speed reaches 74 mph.
Of the eight forecast hurricanes, four are expected to develop into major hurricanes – Category 3, 4 or 5 – with sustained winds of 111 mph or more. The group said there was a 69% chance that at least one major hurricane would make landfall somewhere along the US coast.
The hurricane season in the Atlantic runs from June 1 to November 30, although storms occasionally form outside of these dates. In fact, storms have formed in May in each of the past six years.
Overall, the team predicts that hurricane activity in 2020 will account for around 140% of the average season.
Reasons for the anticipated active season include unusually warm seawater in parts of the Atlantic Ocean and also the absence of El Niño.
One of the main determining factors in hurricane forecasting is whether we are in an El Niño or La Niña climate model.
El Niño is a natural warming of the tropical waters of the Pacific Ocean, 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 the above-average forecast include the expected shortfall of El Nino,” Klotzbach tweeted Thursday.
El Niño typically increases vertical wind shear across the Atlantic, tearing hurricanes apart.
Insurance companies, emergency managers, and the media use these seasonal forecasts to prepare Americans for the hurricane threat of the year. The team’s annual forecast provides the best estimate of activity over the coming season, not an exact measure, according to the state of Colorado.
“We are issuing these forecasts to satisfy the curiosity of the general public and to draw 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 16 to 20 named storms will form, of which seven to 10 will become hurricanes. The firm said three to five storms are expected to hit the United States
Federal forecasters from the National Oceanic and Atmospheric Administration (NOAA) will release their forecast 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 forecast three times over the next several months.