After last winter, many of us are eager to know if there’ll be a repeat “snowmageddon” this year. But meteorology is an imprecise science, as anyone who watches the local nightly news knows. And the slow warming of the globe is making the business of predicting the weather more difficult.
“We know that we’re more likely to have surprises moving forward, but it’s hard to say exactly what those surprises will be,” said Katharine Mach, of the Carnegie Science's Department of Global Ecology.
Bach says one surprise last year was the onslaught of snow here in the Northeast. An area of high atmospheric pressure caused storms that usually deliver snow to California’s mountains to bounce across the continent. The storms dumped snow instead on New England.
“California ended up extra dry and warm, while the Northeast got walloped," Mach said. "Fast forward to the present, though, and things look really different.”
This year the strange California-New England precipitation relationship may continue, but for a different reason—a very strong El Nino. That’s essentially an enormous pool of warm water in the tropical Pacific that’s sending heat into the atmosphere and changing where rain falls.
“California is seeing rain, and will likely see a lot of rain through the next few months, whereas the Northeast is likely to be warmer and drier than normal,” Mach said.
But not everyone agrees. Bob Smerbeck, senior meteorologist at AccuWeather.com, is seeing rain in New England’s near future.
“You will have above normal precipitation, below normal snowfall," he said. "But some of those storms could be more impressive in terms of rain.”
Josh Fox of The Single Chair Weather Blog agrees.
"We have the opportunity here for the next few weeks to see a big snow event," Fox said. "I think that is very, very possible."
So why are there such widely differing forecasts for the Northeast this winter?
The answer is something we all lived through: the hot December. Climate Analyst Erika Spanger-Siegfried
of the Union of Concerned Scientists says no one saw the extreme high temperatures coming—and it’s throwing off the forecasts.
“This fall has been incredibly warm," she said. "The warmest months on record in more than a 100 years of record keeping.”
The unexpected—and uncommon—warmth is interacting with all the other factors that create New England’s weather. And Spanger-Siegfried says it’s tough to predict the repercussions.
“What comes in January and February—I think no one is quite clear on that at this point,” she said.
The warm temperatures are key, particularly this year, because of that extra warm water in the tropical Pacific Ocean.
“When El Ninos, particularly very strong El Ninos like this one, occur on top of increased temperatures, that we can see some very extreme extremes,” Spanger-Siegfried said.
The next few weeks may reveal which way the extremes will go for the rest of winter.
Less snow, more rain—Spanger-Siegfried says whatever happens, the outcome may help us understand how weather will behave in the future, as global temperatures rise.
