In Philadelphia, it should get cold enough, with freezing temperatures overnight from Saturday through Dec. 26. But precipitation is a longshot, with a 10 percent chance according to Weather.com, and with "partly sunny" forecast by AccuWeather.com.
Historically, Santa seeing "new-fallen snow," as in "A Visit From St. Nicholas," is an infrequent event in Philadelphia.
AccuWeather mentions a "less than 25 percent chance" in Philly, New York and Washington, D.C., because "mild air from the Atlantic Ocean plays a role in the low probability."
Only twice in the last 45 years has Dec. 25 dawned in Philadelphia with an inch or more on the ground, according to the National Weather Service: 2009 (8 inches) and 1998 (1 inch). It happened five times, though, in less than a decade starting in the late 50s: 1959 (1 inch), 1960 (1 inch), 1961 (2 inches), 1963 (5 inches) and 1966 (12 inches).
As for snowfall during Christmas Day, that's totalled at least an inch only three times: 2002 (1.1 inches), 1969 (4.1 inches) and 1962 (1.5 inches).
The only other years with more than trace were 1993 and 1976, 0.2 inches each.
Counting trace amounts, only 13 of the last 25 Christmases could claim to be "white."
To see charts for Philadelphia and Allentown, go to: www.erh.noaa.gov/phi/xmasclimate.html.
Contact staff writer Peter Mucha at 215-854-4342 or firstname.lastname@example.org.