NOAA forecasts seventh straight busy Atlantic hurricane season
It’s calling for 14 to 21 named storms, 6 to 10 hurricanes and 3 to 6 major hurricanes
Major hurricanes are of particular concern as they have a tendency to rapidly intensify, or lurch 35 mph or more in strength in 24 hours or less — leaving coastal residents little time to prepare. These major storms are responsible for the overwhelming majority of damage due to wind and storm surge.
Scientists have observed an increase in rapidly intensifying hurricane over the past few decades, linked to warming ocean waters from human-caused climate change.
While wind and surge are of particular concern along the coast, tropical systems bring the risk of serious freshwater flooding hundreds of miles inland due to their torrential rain. In fact, inland flooding has become the leading cause of fatalities from tropical weather systems in recent years. Scientists have also found human-caused climate change is intensifying rainfall in tropical systems.
NOAA’s outlook for another busy season follows a devastating period of heightened hurricane activity in the Atlantic. The 2021 season produced 21 named storms, third most on record, exhausting all of the names of the National Hurricane Center’s conventional naming list. In 2020, a record-breaking 30 named storms formed. The two seasons combined produced the most landfalling storms on record in the United States.
The U.S. saw more Category 4 and 5 hurricane landfalls from 2017 to 2021 than from 1963 to 2016.
Every year since 2016 has generated above average activity in the Atlantic, with five Category 5 storms roaming the basin over that period. A seemingly relentless parade of major hurricanes — including Harvey, Irma, Michael, Laura, Zeta and Ida — lashed the beleaguered Gulf Coast during the six-year window.
The effects of Hurricane Ida last year were so severe — from the Gulf Coast to the Northeast — that the World Meteorological Organization retired it from the rotating list of hurricane names. The storm caused 96 deaths as it tracked from Louisiana to Connecticut and was blamed for $75 billion of damage, the fifth-costliest hurricane on record in the United States.
NOAA’s outlook echoes those made by several research institutions and private companies. Colorado State University, for example, is predicting 19 named storms, with a 71 percent likelihood that the U.S. will be hit by a major hurricane. Similarly, AccuWeather, the private forecast company based in State College, is calling for 16 to 20 named storms.
Many have compared the state of the ocean to that of previous seasons that ended up producing a flurry of intense storms.
What NOAA is calling for
Hurricane outlooks made in the spring have shown considerable improvement over the past decade after not exhibiting much accuracy from the 1980s through around 2013, according to researchers at Colorado State University. Here are the numbers from NOAA’s outlook:
- 14 to 21 named storms, compared to an annual average of 14.4.
- 6 to 10 hurricanes, compared to an annual average of 7.2.
- 3 to 6 major hurricanes, compared to an annual average of 3.2.
It stated there is a 65 percent chance of an above normal season and just a 10 percent chance that it will be below normal.
Signs of a busy season
Many indicators point toward the high probability of a busy season. The position of several key atmospheric features are noteworthy, and ocean appears primed to support some significant storms.
Among the elements being monitored are:
Sea surface temperatures. Hurricanes thrive when water temperatures reach the lower to mid-80s. Hurricanes are heat engines, extracting thermal energy from “oceanic heat content." A greater, deeper reservoir of exceptionally mild ocean water translates to more fuel to generate or sustain a hurricane.
- Water temperatures throughout the entire Gulf of Mexico and western Atlantic are running 1 to 3 degrees above average. The unusually warm water boosts the “potential intensity,” or maximum theoretical strength, a hurricane can achieve.
The loop current. Some researchers have pointed to unusually high temperatures in the Gulf of Mexico loop current as an ominous sign for the season ahead. The loop current is warm-core eddy that meanders north through of the Florida Straits and Yucatán Peninsula. The current could give storms an extra boost if they cross over it — but it’s one piece in a much larger atmospheric puzzle.
La Niña. La Niña is a cooling of sea surface temperatures in the eastern tropical Pacific. It sets in motion a chain-reaction process that favors increased Atlantic hurricane activity. Specifically, it cools the air over that relative temperature minimum in the eastern Pacific, spurring sinking motion there. That makes it easier for air over the Atlantic to rise into big storms.
Wind shear. Wind shear is a change of wind speed and/or direction with height. Too much shear can disrupt a fledgling storm’s circulation and tear it apart before it ever has the opportunity to organize. Shear can spell the demise of a strong hurricane too — imagine spinning a top on a table and ten kicking said table; any subtle jiggle or disruption of the ambient environment can prove pernicious to the rotating system.
- During La Niña summers, there’s typically a reduction in wind shear over the tropical Atlantic. That will make it easier for hurricanes to form and remain stronger for longer.
Hurricane seasons officially begins on June 1
2022′s first storm, once it’s named, will be called Alex. Should all of the 21 names on the National Hurricane Center’s list be used, forecasters will turn to a supplemental list set of names. The supplemental list was developed after the record-setting 30 storms in 2020 which forced forecasters to use Greek letters after 21 storms had earned names.
In recent years, an uptick in early-season storminess has been noted. NOAA has considered moving the “official” start of Atlantic hurricane season from June 1 to May 15, reflecting observed trends in a warming world. That would also match the May 15 start date of hurricane season in the Eastern Pacific.
Irrespective of how many storms form, every year forecasters stress it only takes one storm to have a memorable and potentially devastating impact on a community. In early May, the Hurricane Center led a public awareness campaign to urge preparedness for the upcoming season.
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