Watch for black ice -- and roads that are still snow-covered -- until well into Saturday morning in the wake of Friday's snow.
The quick-moving weather system brought 1 to 3 inches of snow to most of the Philadelphia region. The NBC10 First Alert Weather Team issued a First Alert for the entire region for accumulating snow.
Saturday morning temperatures will be in the teens and 20s across the area, said First Alert Chief Meteorologist Tammie Souza. Stairs, sidewalks and roads may be icy in the morning.
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By noon, sunshine and temperatures in the mid-30s will melt much of the ice and snow. But that slushy mess could refreeze Saturday night.
The snow made for a lousy commute on many Philadelphia-area roads Friday evening.
That coating was enough to lead to 50 crashes or other "traffic incidents" reported at one point in Montgomery County. SEPTA Regional Rail lines, city trolleys and the Norristown High Speed Line all ran up to 10 minutes behind schedule.
NBC10's Drew Smith found drivers at a gas station in the Roxborough section of Philadelphia letting air out of their tires, to better climb the neighborhood's hills.
Some highways and bridges reduced the maximum speed, though that couldn't have made a difference for many drivers who crawled in slow-moving traffic. Making matters worse, a power outage due to a problem with an underground transformer shut off power to traffic lights at some major Center City intersections.
The snow started in the Philadelphia suburbs after noon and quickly spread across the region, ending Friday night.
This third snowfall in one week adds to a snow total that has already doubled the normal accumulation for December in Philadelphia.
Stick with the NBC10 First Alert Weather Team for continuing coverage of the snow.