The western suburbs of Philadelphia are under a winter storm warning ahead of Wednesday's snowfall.
Snow accumulations of 2-4 inches and a light glaze of ice are expected in Chester County and western Montgomery County, according to National Weather Service forecasters. The warning will be in effect from 10 a.m. Wednesday to 1 a.m. Thursday.
A winter weather advisory has been declared in Philadelphia, Delaware County, eastern Montgomery County and Lower Bucks County, from 7 a.m. to 9 p.m. Wednesday, forecasters said. Snow accumulations of 2-4 inches and a light glaze of ice are expected across that area as well.
Slippery, hazardous road conditions could impact the evening commute.
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Forecasters say they have relatively high confidence the precipitation will begin as snow. With the arrival of a warm front, the precipitation type becomes less certain, but the snow should begin a transition to sleet. Though there is a threat of freezing rain if there is more warming.
There is considerable uncertainty still with snow and ice accumulations that are dependent on the timing of changeovers.
Here is the 7-day forecast for Philadelphia from the weather service:
Tuesday night: Increasing clouds, with a low around 26. Northwest wind around 5 mph becoming calm in the evening.
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Wednesday: Snow, mainly after 10 a.m. High near 35. East wind 5 to 8 mph. Chance of precipitation is 90 percent. New snow accumulation of 2 to 4 inches possible.
Wednesday night: Rain and sleet, possibly mixed with freezing rain before 7 p.m., then rain and sleet till 10 p.m., then rain afterwards. Low around 34. East wind 6 to 8 mph. Chance of precipitation is 90 percent. Little or no ice accumulation expected. New sleet accumulation of less than a half inch possible.
Thursday: Rain, mainly before 7 a.m. High near 55. West wind 5 to 11 mph. Chance of precipitation is 80 percent. New precipitation amounts of less than a tenth of an inch possible.
Thursday night: Mostly cloudy, with a low around 33. Northwest wind 6 to 10 mph.
Friday: Partly sunny, with a high near 47.
Friday night: Mostly cloudy, with a low around 32.
Saturday: A chance of rain. Mostly cloudy, with a high near 46. Chance of precipitation is 50 percent.
Saturday night: Rain likely. Cloudy, with a low around 38. Chance of precipitation is 70 percent.
Sunday: Rain likely. Mostly cloudy, with a high near 56. Chance of precipitation is 70 percent.
Sunday night: Mostly cloudy, with a low around 38.
Monday: Mostly sunny, with a high near 50.
Monday night: Mostly clear, with a low around 31.
Tuesday: Mostly sunny, with a high near 46.