But looking back on actual data, that seems optimistic. Since 1891, it has only snowed on Christmas five times.
The last Christmas Day snow was in 1990 (those here will remember that infamous arctic outbreak). Most of the snow fell earlier, but we did manage 0.8" on Christmas. Before that, we had an inch in 1965, a dusting in 1944 and 1915, and about 2" in 1909.
For more recent events: The big snowstorm in 1996 didnt start until Dec.26, and we did manage 2" on Christmas Eve in 1998 but it melted before Santa could arrive.