Shortly before 2 p.m., snow started falling in Philadelphia, a gentle reminder that harsher winter tricks are probably on the way.

Sleet could join the mix this afternoon, and tomorrow morning could see freezing rain, especially in the counties west and north of Philadelphia, according to a winter weather advisory from the National Weather Service for Chester, Montgomery, Bucks, Berks and Lehigh Counties.

"This event would impact the evening commute today and also have an impact on the Wednesday morning commute," the advisory stated.

"It's quite a dynamic situation," said Lee Robertson, meteorologist with the weather service in Mount Holly.

A trip home to the suburbs shouldn't be too bad for those who live close to the city, which will probably just see a "dusting" of snow, he said.

Farther out, however, it's possible sleet could create some patches of ice.

"There's still quite a mix around the area, and that's what we should continue to see for the next several hours," he said midafternoon.

As colder air moves in tonight, the precipitation might become all snow - and then return to rain as warmer air comes in after midnight.

By 11 a.m. tomorrow, "there could be an inch or two of snow and sleet as well as around one quarter of an inch of ice," the advisory predicts.

Prospects for such a morning mess tomorrow raise the possibility that schools might close in some areas.

The freezing rain is most likely in the western and northern parts of Chester, Montgomery and Bucks Counties, Robertson said.

South Jersey, Delaware County and the city could also get a dose of the wintry mix, but are unlikely to get accumulation or freezing rain, he said.

By midday tomorrow, the precipitation should have turned to rain - of the nonfreezing kind - as temperatures rise into the mid or upper 40s.

For more on the forecast, go to: http://go.philly.com/weather.

Contact staff writer Peter Mucha at 215-854-4342 or pmucha@phillynews.com.