Polar Vortex to Return Early in the Northeast

9/24/2014 (Permalink)

While the fall will kick off with days of sunshine and temperatures above normal in some of the region's largest cities, including New York City and Philadelphia, the polar vortex may make its return for short, sporadic periods in September.

"The vortex could slip at times, maybe even briefly in September for the Northeast," AccuWeather Lead Long-Range Forecaster Paul Pastelok said. "There could be a significant shot of chilly air that comes across the Great Lakes region and into the interior Northeast sometime in mid- to late-September."

As conditions in northern Canada begin to set up similar to last fall, getting colder and unsettled quickly, it is likely that this pattern could become a source for colder air to make its way down at times into the United States, inducing a drop in temperatures for the interior Northeast during mid-fall.

"Temperatures will not be as extreme in November when compared to last year, but October could be an extreme month," Pastelok said.

After short-lived days of the polar vortex in September, the weather should turn a bit warmer in November as rain ramps up across areas from New York City to Boston and Portland, Maine, as well as the rest of the region.

"We will see some dry weather in the Northeast, barring any tropical systems, in September and October but in November it will get wet," Pastelok said.

Following a soaking November for Northeastern residents, El Niño will make its debut early this winter, fueling early winter snow across the area.

"December could get kind of wild due to the very active southern jet stream that is going to provide the moisture for bigger snowstorms," Pastelok said. "The Northeast could have a couple of big storms in December and early January."