Some might say "soon??" with the spate of chilly weather since early November.
According to some weather models- it appears to be getting worse- starting as early as this coming Tuesday.
Temperatures don't recover much beyond the warmest highs in the 40's locally- plunging progressively after each storm system passes by through December 21.
Several wet storm systems are in store to affect the Central States not only December 9- but on the 12th through 15th- when we'll have weaker systems moving through.
At least one strong storm system is on the horizon too- now pegged to affect the Central States on December 16-17.
Parts of the northwestern Central States could see blizzard-conditions with this one. Maybe thunderstorms and a chance for severe ones further south and east
Cold air moves as far south as central California according to one model by December 21- with a strong Southwestern U.S. storm system developing by that time.
That storm system could well affect Christmas travel in the Central States.