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Philly can expect about 75 times more snow than it had last winter, forecasters say. El Niño is one factor.

Philly has been remarkably snowless. It's been 90 years since a five-year period was this snow-deprived.

A woman cleans off her car in Northeast Philly after the snows of February 2010, an El Niño winter.
A woman cleans off her car in Northeast Philly after the snows of February 2010, an El Niño winter.Read moreINQ SUWA

If the snowless, balmy winter of 2022-23 suited your tastes, the meteorological winter that began Friday won’t be as palatable, according to those who joust with the chaos of the atmosphere to issue seasonal forecasts.

The consensus that overall temperatures for the Dec. 1-Feb. 29 meteorological season will be above normal in Philly and much of the nation has been holding serve.

But those who do this for a living say that December may end up being more adventurous in the East than earlier forecasts indicated, with a cold shot next week and perhaps even snow worthy of a ruler around here by month’s end.

We will not be offended if you skip to the end to see who is predicting what.

“December could provide an interesting period,” Judah Cohen, polar scientist with Atmospheric and Environmental Research, in Massachusetts, said Thursday.

The guesses on seasonal snow totals — and for a variety of reasons you might have better luck picking stock prices — have snow finishing in the normal range, if not a dash more. The normal in Philly is 22.8 inches, which would be about 75 times more than what was measured last winter — 0.3 inches.

» READ MORE: A grand total of 0.3 inches of snow landed at PHL last winter

Snowfall in the last five years has been half of normal and is the lowest five-year total since the period that ended with the winter of 1931-32, according to National Weather Service records. It now has been more than 670 days since an inch of snow fell upon Philly, a record.

El Niño will be a winter constant

A strong El Niño has developed over the tropical Pacific, where this week sea-surface temperatures were nearly 4 degrees Fahrenheit above normal. The warming, which covers thousands of miles, is expected to persist through the winter, interacting with the overlying air to perturb the west-to-east winds that carry weather to the Americas.

El Niño is producing a “robust response,” the government’s Climate Prediction Center said Thursday in its updated December outlook, which favors normal temperatures here and in about 80% of the contiguous United States.

» READ MORE: El Nino events have been known to coincide with big coastal storms

But no two El Niños have the same effects, cautions Sarah Kapnick, NOAA’s chief scientist. Strong El Niños were present during Philly’s only snowless winter, 1972-73, and its snowiest, 2009-10.

Forecasters anticipate that this one eventually will incite an active storm track along the East Coast, “more likely later in the winter season,” said Paul Pastelok, the longtime seasonal forecaster with AccuWeather Inc.

It isn’t possible to know which coastal lows will ripen into megastorms, and whether the cold air so sparse in recent winters would be available if they do. Coast storms generate winds from the east that can import warm air off the ocean that melts snow into rain.

And nothing happens in isolation in the atmosphere, and El Niño isn’t the only weather agent provocateur. The presence of cold air often is tied to pressure patterns in the North Atlantic and the behavior of the polar vortex, whose winds sometimes slacken and allow Arctic chill to ooze southward.

Climate change

New Jersey state climatologist David A. Robinson, a Rutgers University professor who is an international authority on snow, has observed that for tracking climate change snow is a “very noisy” signal.

The year-to-year totals are all over the place. But for all the randomness in Philadelphia, the current 30-year normal is almost identical to the 22.9-inch average for the first 50 years of snow record-keeping that began with the winter of 1884-85.

» READ MORE: Winters have become warmer around here.

But the trend of milder winters in Philly does track well with worldwide temperature increases.

The warmest meteorological Philly winter on record remains the aforementioned 1931-32, but five of the warmest winters have occurred in the 21st century.

Meteorological winter

Astronomy and meteorology have their differences. The former is predictable. The latter has a certain defiance of the calendar. It has been known to snow in November and hit 90 degrees in April in Philly. By convention, the meteorological community breaks down the season into tidy three-month increments. The astronomical winter doesn’t begin until the solstice, on Dec. 21.

For winterphobes, it is a lock that even though it will be a leap year, the winter of 2023-24 will be the shortest meteorological season of the year, lasting a mere 91 days. February has the fewest days to account for the fact that in its annual orbit, Earth speeds up as it makes its closest approach to the sun during the northern hemisphere winter.

With snowfall, nothing is remotely that certain, but some are giving it a shot; others are deferring.

The outlooks

AccuWeather: 18 to 24 inches. Pastelok says for now he is sticking with this forecast but thinks he might bump up the totals in the likes of Reading and Allentown. In presenting the outlook two weeks ago., 6abc meteorologists Cecily Tynan and Adam Joseph described it as a “low-confidence” forecast.

Fox29: 26 inches. Meteorologist Kathy Orr and her colleagues win the specificity contest. In addition to the 26 inches for Philly, they see 13 days of snow cover and eight “inconvenient” snows of less than 3 inches and four “plowable” snowfalls for 3 inches or more. They also are forecasting seven “grocery store runs.”

WeatherBell Analytics: 30 inches. Unlike just about everyone else, Joe Bastardi, former long-range forecaster at AccuWeather, expects temperatures in the Philly region to be slightly below normal, “and the worry is it will be colder.” In addition, he said in his post, “I don’t expect winter to wait until mid and late winter.”

Climate Prediction Center: The federal government meteorologists have the odds strongly favoring above-normal temperatures and slightly supporting above-normal precipitation for the Philly region. They eschew snow forecasts.

Weather.com: It’s calling for above-normal temperatures, with December the warmest month. However, it also sees below-normal readings in February. It also shies away from snowfall guesses.

“I think that we are all ready for a normal snowfall winter,” said Cohen.

Maybe not everyone.