Ho, ho, ho, they're not kidding.

Snow's a possibility Saturday night and Sunday - Christmas Eve and Christmas Day - in Philadelphia and its nearby suburbs.

Areas to the north have several shots this week to see some snow - or more likely, a wintry mix including sleet and rain. The Lehigh Valley and the Poconos could see a little snow tonight. Even parts of Bucks County could see some snow and sleet Tuesday night into early Wednesday morning - officially the first day of winter. The Poconos could even see hazardous freezing rain Wednesday morning.

Philadelphia and its suburbs, though, are likely to get periods of rain Tuesday night to Wednesday night, and it's not expected to be heavy.

The forecast for the weekend is a mix - a wintry mix. Or mess.

And it's far from certain to happen.

In Philadelphia, Saturday night has a 30 percent of rain, snow and sleet, and Sunday has the same odds without the rain, according to the National Weather Service. Temperatures are expected to dip below freezing.

Sleet seems more likely in the nearby South Jersey suburbs than in the Pennsylvania ones. From Chester County to Bucks County, Sunday's forecast mentions just the chance of snow.

Toward the Shore, the forecast calls for rain Saturday and partly sunny skies Sunday.

The storm could be potent one, as a system coming from the southwest possibly meets up with a coastal low.

Light snow could fall from Washington, D.C., to New York City, according to AccuWeather.com.

But it's too early to have much confidence.

"It's still several days away so we'll know more as get closer," said meteorologist Lee Robertson of the National Weather's Service's Mount Holly office.

Historically, though, White Christmases are rare in Philadelphia. Only seven times since 1958 has Dec. 25 dawned with an inch or more on the ground, according to the National Weather Service: 2009 (8 inches), 1998 (1 inch), 1966 (12 inches), 1963 (5 inches), 1961 (2 inches), 1960 (1 inch) and 1959 (1 inch).

At least an inch fell on Dec. 25 three times: 2002 (1.1 inches), 1969 (4.1 inches) and 1962 (1.5 inches).

Only two other years (1993 and 1976, 0.2 inches each) did more than a trace fall.

Counting trace amounts, only 20 of the last 53 Christmases could claim to be "white."

To see charts for Philadelphia and Allentown, go to: www.erh.noaa.gov/phi/xmasclimate.html.

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.