The National Weather Service in Pittsburgh has issued a winter weather advisory for most of western Pennsylvania, including Allegheny County, from 10 a.m. Friday to 1 a.m. Saturday.

Forecasters say 2-4 inches of snow is possible.

Here is a more detailed look at the forecast.

• Friday: Snow, mainly after noon. High near 21. Southeast wind 5 to 8 mph. Chance of precipitation is 90%. Total daytime snow accumulation of 1 to 3 inches possible.
• Tonight: Snow showers likely, mainly before 9 p.m. Cloudy, with a low around 16. Calm wind becoming west 5 to 7 mph after midnight. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
• Saturday:A chance of snow showers. Cloudy, with a high near 25. West wind 6 to 15 mph. Chance of precipitation is 40%. New snow accumulation of less than a half inch possible.

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