El Niño likely will mean big coastal storms this winter, forecasters say. It might even snow in Philly.

After a mild start, the winter of 2023-24 will likely be a stormy one along the U.S. East Coast with an excellent chance of grocery-shelf-emptying snow scares, if not actual snow. El Niño, at possibly a once-in-a-decade intensity in the tropical Pacific, will be a major player.

That’s the running consensus among the winter outlooks issued so far by the major outlets, including the one released Thursday by the federal government’s Climate Prediction Center.

In Philadelphia, it almost certainly will be more eventful than the winter of 2022-23, which is in a league with saying the Diamondbacks won’t clinch the National League pennant in Arizona this year. (Even if they beat the Phillies in the next three games in Phoenix, they would still have to come back to Philly.)

During El Niño, “Overall, there’s a tendency to get one or two very large snowstorms,” Jon Gottschalck, chief of the climate center’s Operational Prediction Branch, said at a briefing Thursday. “These storms can really explode off the East Coast.”

Said Paul Pastelok, the longtime seasonal-forecast specialist with AccuWeather Inc. “This is not a nickel-and-dime winter. This is big, huge cluster storms that can add up to snow, and if you’re in the right zone, you’ll get it.”

The climate center favors above-average temperatures and precipitation in the Philly region during the Dec. 1-Feb. 29 (it will be a leap year) period. It doesn’t venture guesses on snow, but Gottschalck said the pattern likely will favor significant coastal storms, especially later in the winter, but it is uncertain whether that would mean snow or rain or just a scare.

The weather.com outlook is quite similar. It, too, eschews specific snow forecasts.

AccuWeather is calling for 18 to 24 inches of snow in Philly — the long-term average is 22.2 inches. As Gottschalck and Pastelok said this week, the bulk of that total could fall in just a couple of storms.

WeatherBell Analytics, in an early outlook issued in August, was calling for 30 inches of snow for Philadelphia.

All three forecast services say a cooldown is likely after a mild December.

During El Niño, sea-surface temperatures over vast expanses of the tropical Pacific are abnormally warm. The warmth perturbs west-to-east winds that transport weather to the Americas.

No two El Niños behave the same way, said Sarah Kapnick, NOAA’s chief scientist.

But in this instance, forecasters see a track developing that would transport storms across the Gulf Coast that then make a sharp left turn when they reach the Atlantic.

That path would allow storms to gather copious moisture, said the climate center’s Gottschalck. That doesn’t necessarily mean snow: Storms that hug the coast tend to import rainy winds off the warmer ocean; if they stray too far to the east off the coast, they would have no impact around here.

This is an especially strong El Niño, with water temperatures about 2.5 degrees Fahrenheit above average, and it is forecast to persist at or near that intensity through the winter.

Strong El Ninos have lasted through the winter only seven other times dating to 1950, according to climate center records. Those winters around here tended to be extreme in either direction. Snow totals ranged from 0.0 inches, in 1972-73, to 79 in 2009-2010, when Philly was clocked with mega snowstorms around the solstice and in February.

Gottschalck invoked that winter on Thursday, and it was mentioned in the other two outlooks.

Weather.com’s Todd Crawford said that “the conditions in the atmosphere right now resemble the 2009-10 El Niño.” WeatherBell’s Joe Bastardi said he wouldn’t rule out a 2009-like December to remember, but the core of the worst part of winter, relative to averages, should be from mid-January onward.

AccuWeather’s Pastelok does not see an early-season snow blitz. “December just doesn’t look cold enough,” he said.

Arguing against snow is that outbreaks of frigid Arctic air that migrate southward tend to occur less frequently, said Gottschalck.

And, of course, in line with the worldwide warming trend, the Philadelphia region has had a run of mild winters in recent years.

Three of the five warmest winters in Philadelphia’s period of record dating to 1874 have occurred in the 21st century, including last year’s, when the city experienced all of 0.3 inches of snow.

That would be hard not to top.