No snow yet this winter on Long Island is due to La Niña, a pressure gap, and warmer ocean temps, meteorologists say

Long Island's snow haters probably can keep rejoicing — along with any rain lovers.

No appreciable snow has fallen yet this winter, and meteorologists said Friday they expect the trend to continue at least until mid-month.

A potential storm over the Martin Luther King Day holiday likely will deliver no snow in the tristate except perhaps south of New York City, in New Jersey, meteorologists said. And there's a very slim chance of snow this Sunday into Monday.

“Except for a weeklong cold blast the week before Christmas, cold air has mostly been bottled up to the north thanks to unusually strong jet stream pattern,” Jeff Masters, a Yale Climate Connections meteorologist and co-founder of Weather Underground, said by email.

Predicting that trend will persist over the next two weeks, he added: “There is the potential for a significant snowstorm next weekend, though preliminary indications are that the snow will be mostly inland over the Northeast United States.”

The La Niña weather system, a larger than usual gap between low pressure near Greenland’s polar regions and high pressure around the Azores — the archipelago 870 miles west of Lisbon — and some warmer local ocean temperatures are driving this oddly warm and snowless period, forecasters say.

La Niña arises when the equator’s easterly trade winds strengthen, pushing the Pacific toward Asia, and raising the ocean's coldest layers to the surface off South America’s west coast. El Niño, which reverses those ocean flows, forms when those trade winds ease or change direction. 

Third year of La Niña

This is the third La Niña winter in a row. This has created a “wavier and more variable” jet stream, Joshua Feldman, head of meteorology, with WeatherOptics, data-driven forecasters in New York, said by email.

“As a parade of storms have pounded the West Coast over the past few weeks, the wavy jet stream has drawn them northeastward into the Plains and then the Great Lakes,” reinforcing cold air to the north and west, while delivering more warm, subtropical air to the south and east.

And that difference between the Greenland and the Azores systems tends to straighten the jet stream, “making the Northeast less prone to extended cold outbreaks and keeping the storm track away from the coast,” he said. By mid-January, however, this Greenland-Azores pattern may erode.

Lenny Giuliano, a Rhode Island meteorologist, also noted sea temperatures were a bit warmer this summer — and are cooling a bit slowly.

“If the winds are coming from the southeast,” he said, “that warm air from the ocean … seems to push storms a little further west than Interstate 95,” so only rain falls east of that north-south East Coast artery.

This weekend’s odds of snow are only 20%, said Bill Goodman, a National Weather Service meteorologist, as just the “northern fringe” of the precipitation springing from a low pressure system heading out to sea will brush this area. 

“There is a chance of light snow for the area Sunday night into early Monday morning,” the weather service said.

Added Goodman: “The chances are better south of the city, as you go into New Jersey.”