Three to six inches of snow might fall Friday in parts of Chester, Montgomery and Bucks Counties, according to the National Weather Service.
The Lehigh Valley should get even more, and upper elevations in the Poconos might even get a foot of snow.
Philadelphia, Delaware County, South Jersey and Delaware, however, should basically see rain.
"It might start out as a brief mixture of snow and sleet and stuff, but then we do expect it to turn over to rain fairly quickly," said Joe Miketta, a meteorologist in the service's Mount Holly office.
The same geographical pattern of rain and snow should repeat itself when a second west-to-east storm should arrive on Saturday night.
Today, in the farther parts of the suburban counties, snow should start coming down around daybreak and continue into the evening, Miketta said.
A third storm could arrive Dec. 24, but warmer temperatures make more snow unlikely.
"Right now that looks like it's warm enough to be all rain," he said.
For more on the forecast, go to http://go.philly.com/weather.