The National Weather Service issued a winter storm warning for the region through 5 p.m. Monday as up to 8 inches of snow could fall in some areas.
The weather service says snow could fall at a rate of 1 to 2 inches per hour at the height of the storm. Accumulation of 4-8 inches of snow was predicted for Philadelphia and the suburbs including Berks, Chester and Montgomery counties.
Driving could be hazardous during the height of the storm, with visibility of one half mile or less possible.
The snow is wet and heavy, possibly causing tree limbs to come down across roads and power lines, and leading to outages, the weather service warned.
It also warned of freezing conditions Monday night that could cause standing snow and slush to freeze leading to slick road conditions. Drivers are urged to be cautious when traveling today.