Janice Stillman is predicting this winter in Philly will be milder than last — not a stretch, considering our region experienced what felt like downright balmy temperatures well into December.
But Stillman, who’s been an editor with The Old Farmer’s Almanac for the past 16 years, is also predicting a blustery winter for Philly with the potential to dump way more snow than we saw last year. She says Thanksgiving Day will be “beautiful.” There will be periods of rain and snow over the week of Christmas. And a massive snowstorm is coming for our area in mid-February.
“It just sort of depends,” she said in an interview, “on how hard the wind blows.”
Safe to say those predictions aren’t exactly verifiable.
The Old Farmer’s Almanac, based in New Hampshire, has been notable for decades for its longterm weather forecast that predicts changes in weather based on the climate of different regions. The Almanac has always kept its methods close to home, but says its predictions are based on a mix of solar science, climatology and meteorology. They say they’re 80 percent right, on average.
Jim Bunker, the observing program leader with the National Weather Service in Mt. Holly, N.J., says we can probably just plan on an about average winter with precipitation levels around normal. But, he says, it’s generally quite hard to predict the weather forecast more than even a few days out.
“I know the words are out about the Farmer’s Almanac saying it’s going to be a blustery winter,” he said, “and I have to fight with that.”
What Philly can reasonably expect
As early as springtime last year, meteorologists were predicting that warm weather would be felt far into the winter months. Maybe they couldn’t definitely say we’d be able to get away with shorts on Christmas Day, but they knew warmer-than-average temps were coming due to an El Niño forming in the Pacific. So by last fall, predictions for the winter weather were something like this:
But by around the same time this year, models showed a La Niña was forming — basically creating the opposite effect of an El Niño. So the feeling about what winter would be like felt a little more like this:
Now? Bunker, from the National Weather Service, says it’ll probably be neither. Let us explain.
El Niño and La Niña are systems that that involve trade winds and the temperature of the Pacific Ocean, and their presence can throw off weather patterns across the globe in a variety of ways. Last year, meteorologists said the El Niño that formed in the Pacific — causing the temperature of the ocean waters to rise — was one of the strongest on record, causing those mild temps we felt in the winter.
That’s because the Pacific Ocean impacts everything else. Picture a creek, Bunker explained; if something upstream is disrupted, it impacts what happens downstream. Because of how air circulates across the globe, we’re downstream.
“So that,” he said, “is why we look at the Pacific to determine what could be happening across our area.”
After last year’s massive El Niño, some models in June predicted a weak La Niña this year, which would bring colder air to our area and cause a dumping of snow and precipitation throughout the winter months. NOAA had a “La Niña Watch” in place as sea surface temperatures were below average. Here’s what that model, from Accuweather, looked like at the time (note the HEAVY SNOWFALL and PERSISTENT COLD in our area):
Since that time though, the predictions of a La Niña have subsided. NOAA canceled its La Niña Watch and by mid-September, meteorologists were saying there was about a 60 percent chance La Niña would be a no-show this year. Bunker said now conditions in the Pacific are leaning toward “ENSO-neutral,” a fancy way of saying: No El Niño and no La Niña. Probably just an average year with conditions near “normal.”
Average or normal weather conditions are largely based on long-term averages. For example, Philadelphia averages 23 inches of snow per year.
“Starting off [winter], things are looking pretty much normal, maybe slightly above normal for temps and near normal to slightly below for precipitation,” he said. “We have to see what happens in January. Things can always change in January.”
What the Farmer’s Almanac says
The people at the Farmer’s Almanac know readers take what they say with a (huge) grain of salt. Predicting the weather months in advance is an imperfect science, at best. Two years ago, when that “polar vortex” hit, the Farmer’s Almanac says its accuracy rate for long-term weather prediction was somewhere around 96 percent. Last year, when the El Niño formed, they were 55 percent accurate.
This year, Stillman said she believes our area could see more precipitation than normal. That goes along with their nationwide outlook, which looks like this:
The Old Farmer’s Almanac, which has been making predictions since 1792 and still distributes three million copies a year to this day, operates on a belief that sunspots influence weather patterns more than modern science would agree with. The Almanac’s founder, Robert B. Thomas, used sunspots — magnetic storms on the surface of the sun, originally discovered by Galileo — to predict the weather.
Stillman said the Almanac still uses that “solar science” in combination with Thomas’ “secret formula” to predict long-term weather patterns, like the idea that Philly just might see more snow than usual this winter season. And she knows mainstream meteorology doesn’t agree with her.
“Some people simply don’t believe that the sun can influence the atmosphere the way we’ve described,” she said. “We just do.”