The National Oceanic and Atmospheric Administration’s Climate Prediction Center, citing factors including record-high sea surface temperatures, has updated its prediction for the 2023 Atlantic hurricane season from “near normal” to “above normal.”
The Climate Prediction Center, a division of the National Weather Service, now predicts a 60-percent chance of between 14 and 21 named storms, of which six to 11 could become hurricanes, and two to five of them major hurricanes. An outlook issued in May predicted just a 30-percent likelihood of an above-average hurricane season. The likelihood of near-normal activity has decreased from 40 percent in May to 25 percent, according to a NOAA document issued last Thursday. The updated prediction includes a 15-percent likelihood of a below-normal season.
NOAA’s updated 2023 forecast covers the historical hurricane season, which runs from June 1 through Nov. 30. Named storms are those with winds of 39 miles per hour or greater, while hurricanes feature winds of 74 miles per hour or greater. A hurricane is classified as major if its winds are 111 miles per hour or greater. NOAA’s range of 14 to 21 named storms — six to 11 of them hurricanes, and two to five of those major hurricanes — are provided with 70-percent confidence, according to the agency. Storms that have already formed this season are included in the updated range.
“The Atlantic basin experienced an active start to the hurricane season with five storms that have reached at least tropical-storm strength, including one hurricane already,” according to NOAA’s announcement updating its predictions. It quotes Matthew Rosencrans, the Climate Prediction Center’s lead hurricane season forecaster. He cites the ongoing El Niño climate pattern in the Pacific Ocean, which can affect weather worldwide, and the warm phase of the Atlantic multi-decadal oscillation, an ongoing series of long-duration changes in the North Atlantic Ocean’s surface temperatures, as the primary factors expected to influence the 2023 hurricane season. The Climate Prediction Center also points to a below-normal wind shear forecast and a near or above-normal West African monsoon as factors shaping the updated forecast.
There is a greater than 95-percent chance that El Niño will continue through the Northern Hemisphere winter, according to the Climate Prediction Center, and “El Niño usually results in atmospheric conditions that help to lesson tropical activity during the Atlantic hurricane season.” However, to date “those limiting conditions have been slow to develop and climate scientists are forecasting that the associated impacts that tend to limit tropical cyclone activity may not be in place for much of the remaining hurricane season.”
Climate scientists have long warned that a warmer climate increases the likelihood of more extreme weather events. Late last month, waters in the Florida Keys surpassed 101 degrees, far above the historical norm, amid innumerable manifestations of climate change including unprecedented heat waves and wildfires around the world.
John Andrews, who until his retirement was a research engineer at Brookhaven National Laboratory, said that “Predicting the frequency of hurricanes in any given year is dicey to say the least. Climate scientists talk about averages over many years.” But Mr. Andrews, who is co-leader of the Long Island East chapter of the Citizens’ Climate Lobby, added that “The consensus is that climate change might not increase the frequency of hurricanes, but it will increase the intensity of those that do occur. It’s also likely to increase the amount of rainfall delivered. Additionally, rising sea levels will make storm surges more dangerous.”
When the town board met on Tuesday, Supervisor Peter Van Scoyoc told his colleagues that “historically, our storms usually come in September and beyond” but “certainly, one could come anytime during the summer, from June on.” He said that he has asked Bruce Bates, the town’s emergency preparedness coordinator, to come to the board’s Sept. 5 work session “so that we can do a public presentation to remind residents and visitors to be prepared for hurricane season: what kind of preparations that they can undertake to make them in a better situation if we were to have the unfortunate event of a storm coming to us, and just to go over what the town’s emergency responses are to ensure that our town departments are properly situated as well going into the season.”
NOAA put into operation the Hurricane Analysis and Forecast System, a new hurricane forecasting system, on June 27. It is running in tandem with existing models for the 2023 season and will replace them as NOAA’s premier hurricane forecasting model.