Forecasters cast yet another early vote for a mild winter in Philly

For those who view winter as a punitive experience, the long-range forecasters continue to send their warm wishes, with the early seasonal outlooks not showing much love for snow partisans or plow contractors.

The government’s Climate Prediction Center on Thursday joined the likes of AccuWeather Inc. and Weather.com in saying the scientific tea leaves favor a generally mild Dec. 1-to-Feb. 28 period — the meteorological winter — in the Philadelphia region and in much of the Mid-Atlantic.

The state of the atmosphere also argues for below-normal snowfall along the Northeast Corridor, Jon Gottschalck, chief of the climate center’s Operational Prediction Branch, said at teleconference.

Don’t throw away the shovel just yet, however. While long-range forecasters almost always skate on thin ice, Gottschalck and others advise that this time around the ice may be membrane thin.

The waters over thousands of miles in the tropical Pacific remain abnormally cool, a La Niña event, and likely to stay that way through the winter. This one is unusual in that it is entering its third winter, a so-called triple-dip La Niña.

Since weather tends to move west-to-east, the cooling of the overlying air out that way affects upper-air currents to deliver systems to the United States.

But this would be only the third triple-dip La Niña in records dating to 1950, and Gottschalck said that’s too paltry of a sample on which to draw conclusions. The last time it happened was during the winter of 2000-01, quite a cold and eventful one around here. The one before that, 1975-76, was for the most part yawn-worthy.

» READ MORE: What happened to that hyper-active hurricane season?

La Niña does appear to favor displacing East Coast storm tracks to the west, he said, and thus coastal storms would be apt to bring warm air off the ocean inland, arguing against big snows for the I-95 cities.

Worth noting, however, is that La Niña, which reduces the upper-air winds that shred incipient tropical storms, was a big reason why the consensus forecasts called for a hyperactive hurricane season in the Atlantic Basin. The tropical-storm activity has been about normal, and the season shows every sign of ending with a whimper.

It’s beginning to look a lot like last winter, says Todd Crawford, veteran seasonal forecaster for weather.com, with a generally strong polar vortex, which would tend to limit frigid outbreaks by confining the coldest air to the Arctic regions.

That was the case last winter, which was the 12th-warmest in Philadelphia in records dating to the 1870s.

When those swirling winds are weakened, cold air can spill deeply into the United States, as they did historically in Texas in the winter of 2020-21.

» READ MORE: The power of the polar vortex was evident in the winter of 2020-21

If the vortex does visit, AccuWeather long-range forecaster Paul Pastelok says the best chances would be February.

Tom DiLiberto, climate scientist with NOAA’s Climate Program Office, says you can pretty well forget about the impacts of that undersea Hunga Tonga-Hunga Ha’apai volcano, which erupted on Jan. 15 and ejected a massive plume of water vapor into the stratosphere.

He says that if anything it would have a “very, very slight” global-warming effect, suggesting it won’t exactly be a snow-maker.

The climate center has the probabilities favoring above-normal temperatures for the region, with only a 30% chance being below average.

AccuWeather is more bullish on the warmth, predicting readings averaging better than 3 degrees above normal in Philly. It also is calling for snowfall below long-term averages.

Weather.com eschewed a snow forecast, but it’s on board with above-average temperatures.

» READ MORE: A warmer world doesn't mean the end of winter

Judah Cohen, a scientist with Atmospheric and Environmental Research Inc., who unabashedly roots for snow, isn’t seeing much encouragement in Siberia. His research has suggested connections between October snow over there and the winter over here.

“A fast start has basically crashed and burned,” he said.

In short, at least in the early going, Phillies fans might have more reason for hope than winter-philes do.