Forecasters at a benchmark hurricane research program predict there will be four major cyclones in the Atlantic in 2021, or storms that reach Category 3 or higher.
The prediction comes from the Tropical Meteorology Project at Colorado State University. Researchers there say warmer than normal tropical waters and the expected absence of an El Niño weather pattern point to an above-average season.
The El Niño is otherwise known to suppress storms in the Atlantic.
- 17 named storms
- Eight total hurricanes
- 35 days in which a hurricane is active
- Nine days in which a major hurricane is active
The forecast is nearly identical to the Project's early prediction for the 2020 season, also issued in April of that year, when the first signals of tropical activity begin to emerge.
Last year, however, exceeded expectations. There were an unprecedented 30 named storms, including six major hurricanes.
Some areas were dealt a particularly unlucky hand, with two storms hitting the western Louisiana coast about a month apart, and two major storms hitting a stretch of Nicaragua's coastline less than two weeks apart.
Jhordanne Jones, a forecaster at CSU, said the early conditions this year are lining up in a similar pattern to 2020, with warm tropics early in the year and little likelihood that storm-suppressing wind shear will emerge from developing climate patterns.
"We're exactly where we were just a year ago," Jones said. "I'm sure there's going to be a lot of anxiety, depending on how 2021 decides to unfold."
The 2020 season has had other reverberations into this year.
The meteorology group that names hurricanes decided it will stop using Greek names if the normal list of storm names runs out. The system caused confusion and some storms with Greek names were so destructive their monikers would normally be retired from use.
Additionally, the National Hurricane Center, the gold standard agency for hurricane tracking in the United States, will start issuing tropical weather advisories earlier and is considering whether to start the official "hurricane season" earlier as well.
Right now, hurricane season runs from June 1 to Nov. 30, but storms have formed in every month of the year.
The exceptional 2020 season will also be incorporated into the new "climate normals" that forecasters use to make comparisons, which are being updated later this year. For the past decade, forecasters have been using hurricane seasons from 1981 to 2010 to compare with their predictions and declare whether they expect a season will be more or less active than the recent past.
CSU, for example, used the dataset ending in 2010 in calling for an "above average" season in 2021. But if they'd compared it with a dataset that ends in 2020, Jones said, their forecast would probably be considered "average."
Recent hyperactive hurricane seasons in not only 2020 but also 2017 and 2005, are pushing the normals higher. At the same time, there still isn't scientific agreement about whether recent years of higher hurricane activity in the Atlantic are being caused by planet-warming climate change, or some other process.