Chance Of Winter Weather In Eastern PA As Polar Vortex Looms

There is a chance of some winter weather — including freezing rain, sleet and even snow — Monday night into Tuesday morning in Eastern Pennsylvania, according to the National Weather Service. The forecast has caused some parts of the region to be under a Winter Weather Advisory.

The National Weather Service has issued a Winter Weather Advisory in Upper Bucks County, as well as Somerset, Carbon, Monroe, Berks, Lehigh, and Northampton counties. A Hazardous Weather Outlook has been issued elsewhere in the Philadelphia region.

According to forecasters, there's a chance of snow showers in the Philadelphia region after 5 p.m. Little or no ice accumulation is expected; snow and sleet accumulation of less than a half inch is possible.

More accumulation is likely as you head north. Up to one inch of snow and a light glaze of ice is expected in northwest New Jersey, the Lehigh Valley and the Poconos. In those areas, plan on slippery road conditions, especially during the Tuesday morning commute, the NWS warns.

In the meantime, the forecast for the Philadelphia region calls for the precipitation to fully change to rain by Tuesday morning. Any trace amounts of snow or ice that may have accumulated will likely disappear by Tuesday afternoon, when a high temperature of 50 degrees is predicted.

The weather targeting Eastern Pennsylvania is a "warning shot" for winter's return late in the month and early February, AccuWeather said.

"A major stratospheric warming event has begun," according to AccuWeather Senior Meteorologist Brett Anderson. When the stratosphere warms suddenly over the North Pole, it weakens the polar vortex and causes the normally pent-up frigid air to be displaced southward, according to AccuWeather.

During the latter part of January, temperatures may shift from generally at or above average to slightly or significantly below average in the Northeast as that cold air from the North Central states tries to work eastward, according to AccuWeather.

Substantial cold weather is still anticipated during February. How severe and long-lasting the colder weather is may depend somewhat on the southward position of the polar vortex and the extent of snow on the ground, forecasters say.

RELATED: New Winter Outlook Issued For PA: Here's When The Worst Is Coming

Here is the local forecast:

This Afternoon: A chance of snow showers, mainly after 4pm. Mostly cloudy, with a high near 36. Southeast wind 3 to 5 mph. Chance of precipitation is 40%. Little or no snow accumulation expected.

Tonight: A chance of rain, freezing rain, and sleet before 2am, then snow and sleet likely, possibly mixed with rain. Mostly cloudy, with a low around 31. Southeast wind 3 to 7 mph. Chance of precipitation is 60%. Little or no ice accumulation expected. New snow and sleet accumulation of less than a half inch possible.

Tuesday: A chance of rain before 11am, then a slight chance of rain after 5pm. Partly sunny, with a high near 50. Southwest wind 3 to 5 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tuesday Night: Rain likely, mainly between 10pm and 1am. Mostly cloudy, with a low around 37. South wind 5 to 14 mph becoming west after midnight. Winds could gust as high as 24 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Wednesday: Partly sunny, with a high near 43. West wind 14 to 17 mph, with gusts as high as 33 mph.

Wednesday Night: Mostly cloudy, with a low around 30.

Thursday: Partly sunny, with a high near 36.

Thursday Night: Partly cloudy, with a low around 22.

Friday: Mostly sunny, with a high near 33.

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