La Niña, which strengthens Atlantic hurricanes and western drought, is gone and could make weather forecasting trickier

Weather forecasts will be trickier for Long Island meteorologists now because of the fading La Niña weather pattern in the Pacific that helped give the region a spring-imitating winter, experts said Thursday.  

The unusual third La Niña in a row that increased Atlantic hurricane activity and worsened western drought is gone, the National Oceanic and Atmospheric Administration said Thursday. La Niña might give way to neutral conditions — depriving meteorologists of one of their stronger, longer-term signals.

“The problem is that when you base everything on what happens in the Pacific, you go into neutral, there is no definite signal for what would happen in the Northeast,” said New York State climatologist Mark Wysocki.

“Right now, we’re living in an environment where the signals are fairly weak.”

During a La Niña pattern, strengthening easterly trade winds push the waters of the Pacific Ocean toward Asia. This lets the sea’s coldest levels come up to the surface off Latin America’s west coast.

The pattern heightens the risk of hurricanes as there is less wind shear in the Caribbean to blast them apart.

However, the jet stream tends to veer north, a boon for the East Coast, as those hurricanes tend to head to the Gulf, the Ohio Valley and the Great Lakes.

La Niña might be replaced by its opposite, the El Niño pattern.

“During the summer, there is a chance of a transition to El Niño,” it added.

That might spur a lull in the June to November hurricane season.

“The Atlantic hurricane seasons during El Niño events tend to be quiet, because of increased wind shear,” explained Jeff Masters, a Yale Climate Connections meteorologist and co-founder of Weather Underground.

Looking ahead, said Masters: “If El Niño sticks around and lasts through the winter, El Niño increases the odds of warmer-than-average temperatures across the northern tier of states, with drier conditions also favored."

Since 1960, only four hurricane seasons — 1963, 1969, 2004 and 2018 — had average or above average activity, as gauged by the Accumulated Cyclone Energy index, he said.

Timing in weather certainly can make all the difference.

In 2018, “a weak El Niño event was just getting going,” Masters said. “The developing El Niño event did not arrive in time to significantly dampen hurricane activity, however,” he said, ”and the season was near-average by most measure, with 15 named storms, eight hurricanes and two intense hurricanes and an Accumulated Cyclone Energy index of 133.”

Last year’s hurricane season measured 95.1 on this scale, according to research by Phil Klotzbach, senior research scientist, Department of Atmospheric Science at Colorado State University.

And it was “near normal,” the National Hurricane Center says, with 14 named storms, seven hurricanes — three of which were major, including early September’s Fiona.

With AP