The National Weather Service has posted a wind-chill advisory effective 10 p.m. today through 11 a.m. Wednesday.
In Pittsburgh, wind-chill readings are expected to be 10 to 20 below zero tonight and Tuesday morning. Those readings are forecast to rise to zero to 10 below during the day Tuesday before falling back to 10 to 20 below zero Tuesday night and Wednesday morning.
The air temperature is forecast to dip to as low as zero tonight and 3 below zero on Tuesday night, with winds here at 10 to 20 mph gusting to 30 mph.
The weather service said 1 to 2 inches of snow was possible in Pittsburgh today, with less than an additional inch overnight.
Shortly after 1 p.m. it issued a special weather statement warning of snow showers that might reduce visibility and quickly coat roads in northwest Allegheny, southern Beaver and northwest Washington counties, including Moon and Weirton.
Shortly before 2 p.m. it extended the area to include Sewickley, Aliquippa, Cranberry, Franklin Park, Mars, Natrona Heights, Allison Park, Economy, Wexford, Gibsonia and West Deer.
The website 511pa.com showed snow or icing conditions on parts of Interstate 376 west of Pittsburgh International Airport and I-79 north of the Pennsylvania Turnpike. Hazardous travel conditions extended north on I-79 all the way to Erie.
Accumulations of a half-inch to one inch were possible on the northern part of the Parkway North as well, the weather service said.
Temperatures are expected to rebound slightly on Wednesday, with a forecast high of 17, and Thursday, with a high in the upper 20s, according to the weather service.
Meanwhile, a winter weather advisory will be in effect from noon today to 6 a.m. Wednesday in Lawrence, Venango and Forest counties, with up to 10 inches of snow possible in some parts of those counties, and a lake effect snow warning has been posted for Crawford and Erie counties, where 10 to 20 inches of snow are forecast by Wednesday.weather - mobilehome - homepage - breaking - region
Jon Schmitz: firstname.lastname@example.org, 412-263-1868 and on Twitter: @pgtraffic.