As Long Island enters the peak of Atlantic hurricane season, the National Oceanic and Atmospheric Administration is upping its call as to likely activity.
The chance for below-normal is decreased, with “a higher likelihood of a near-normal or above-normal season,” NOAA said Thursday in an update to the Atlantic Hurricane Season Outlook it issued in May.
That means a 70-percent chance for 12 to 17 named storms, with five to eight of them becoming hurricanes, two to four of those major. In May the outlook was for 10 to 16 named storms, four to eight of them hurricanes, with one to four of them major.
The seasonal average is for 12 named storms, six of them hurricanes, with three of them major.
Still, the take-away is not just the number of storms, Kathryn Sullivan, NOAA administrator, said in May.
“Don’t bank your course of action,” she said, on whether a season is deemed low, medium or high. Hurricanes happen annually and “one can hit or brush the coast near you.”
As underlying conditions have become clearer, the numbers have been adjusted upward, said Gerry Bell, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center.
That includes “weaker vertical wind shear and weaker trade winds over the central tropical Atlantic and a stronger west African monsoon,” he said. That’s as the climate pattern known as El Niño, which affects weather worldwide and increases the wind shear that makes it harder for storms to form, has ended.
The season is not expected to move to the “extremely active” level, he said, thanks to “competing conditions” that include “less conducive ocean temperature patterns in both the Atlantic and eastern subtropical North Pacific, combined with stronger wind shear and sinking motion in the atmosphere over the Caribbean Sea.”
The May outlook indicated at that time that “the climate signals that influence the formation of Atlantic storms make predicting this season particularly difficult.”
One question mark included the potential intensity and impacts of La Niña, the flip side of El Niño, which creates more favorable conditions for storms to develop.
But now, should La Niña develop, Bell said in a Thursday news release, it “will most likely be weak and have little impact on the hurricane season.”
NOAA’s updated figures include the five named storms, two of them hurricanes, that have already occurred this year: hurricanes Alex and Earl, and tropical storms Bonnie, Colin and Danielle.
The Atlantic hurricane season technically runs from June 1 to Nov. 30.