The coming Atlantic hurricane season is “expected to be a busy one,” with the likelihood of as many as 19 named storms, including as many as six major hurricanes, a federal weather scientist said Thursday. That worrisome forecast could be further complicated by the coronavirus pandemic, which is hobbling relief agencies and could turn evacuation shelters into disease hot spots.
Gerry Bell, the lead hurricane season forecaster with the climate prediction center of the National Oceanic and Atmospheric Administration, delivered the forecast as part of the annual announcement of the agency’s hurricane season outlook.
In the probabilistic language the agency uses to describe the season ahead, there is a 60 percent chance of an above-normal season, and just a 10 percent chance of a below-normal season. Agency scientists also estimated a 70 percent chance of between 13 to 19 named storms. Of those, NOAA predicted between three and six would be major hurricanes.
In an average hurricane season there are 12 named storms (those with winds of 39 miles per hour or higher) and three major hurricanes (when winds reach 111 m.p.h. or more). The Atlantic hurricane season starts June 1 and runs through Nov. 30, though the emergence of Tropical Storm Arthur this month made this the sixth year in a row in which a named storm has slipped in before the official beginning of the season.
During the call with reporters to announce the forecast, Carlos J. Castillo, acting deputy administrator of the Federal Emergency Management Agency, said the coronavirus pandemic could add to the challenges of the season.
FEMA advised state and local emergency managers to prepare for a range of new challenges, including “supporting health and medical systems that are already stressed, with an expectation that those emergency services will continue to be taxed into hurricane season.”
One of the challenges facing disaster officials is how to protect people forced to leave their homes without exposing them to the coronavirus. In previous storm seasons, local officials and nonprofit groups have relied on what they call congregate shelters — rows of cots in high school gymnasiums, church basements or other crowded spaces.
The American Red Cross, which manages most of the country’s shelters, is “prioritizing individual hotel rooms over congregate shelters,” according to Stephanie Rendon, a spokeswoman for the organization.
But she said individual rooms might not be an option in large-scale disasters like hurricanes, so the Red Cross would instead rely on “additional safety precautions” for group shelters, such as health screenings, masks, additional space between cots and extra cleaning and disinfecting.
The coronavirus has also put new strain on FEMA, which as of Thursday was managing 103 major disasters around the country, according to agency records.
Just 38 percent of FEMA staff members were available to be deployed to a disaster zone; for some of the agency’s specialized staff, such as field leaders and safety experts, less than one-quarter were available.
“We have not taken our eye off the ball about handling other disasters,” said Peter T. Gaynor, the FEMA administrator, in a call with reporters this month.
Factors contributing to this year’s prediction of above-normal activity include warmer-than-average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, along with reduced vertical wind shear, which can keep storms from forming or from becoming stronger. There is also an enhanced west African monsoon.
Jennifer Francis, a senior scientist at the Woods Hole Research Center, said in a statement, “If we want to keep these dangerous patterns from accelerating, we need urgent action by government and private sector leaders to shift us away from fossil fuels and toward clean energy.”
However, Dr. Bell of NOAA said in Thursday’s call, other factors have, at least so far, had a far greater effect on hurricane strength in the North Atlantic than climate change.
Those include a decades-long cycle of rising and falling sea-surface temperatures known as the Atlantic multidecadal oscillation, and the phenomenon of El Niño and La Niña in the Pacific. El Niño tends to suppress hurricane activity in the Atlantic; La Niña promotes storm activity there.
The Atlantic has been in a “high-activity era” since 1995, Dr. Bell said. This year, El Niño is currently in a neutral state, which neither suppresses nor enhances storm activity. If La Niña should develop during this season, then the high end of the agency’s forecast becomes more probable.
Dr. Bell added that other elements of climate change were contributing to the destructiveness of storms, including rising sea levels and the increased moisture content of warmer air, which can mean more rainfall and flooding from storms. In addition to climate issues, “our coastlines have built up enormously,” he noted, which has put more people in harm’s way whenever any storm approaches.
For all of the attention that NOAA’s annual announcement receives, though, it doesn’t offer a definitive verdict on the hurricane season, said Andrew Dessler, an expert in climate change at Texas A&M University.
He called the forecasts “an interesting scientific problem” but said, “I don’t think they tell us much about how to prepare.” They cannot predict landfall, for example. And, even in a year with very few storms forecast, “it just takes one to be a true disaster.”
Therefore, he said, for people near the Gulf of Mexico or on the East Coast, “you should be ready for a big storm, regardless of the forecast.”