I think it's more of a warm front followed by a cold front thing than anything else. The temps this winter have seemed to really bounce around from warmer than normal to normal temps every few days to every other week.
Of course it is, but if winters are mild as in this winter, the chances of clashes of a warm and cold front of significant differences in temperature are greater.
Allegedly the theory is, back during the last ice age there were some hefty temperature differentials that produced some very wicked storms where temps really varied significantly.
