Prepare for Arctic cold and a hodgepodge of winter precipitation Saturday night through Sunday night.
The remnants of a powerful Pacific storm will combine with a clashing Arctic/Sub-tropical air mass to produce bitterly cold conditions and a full spectrum of winter precipitation - freezing rain, sleet (ice pellets) and snow.
True blue Arctic air will overtake the state Saturday night and Sunday morning with temperatures falling into the 10s and 20s by Sunday afternoon with wind chills at and below 0. The depth and location of the freezing (and below freezing) air will be the biggest determining factor of precipitation type.
Initially, this freezing depth will be very shallow, 1,000 ft. to 2,000 ft. deep. This will promote freezing rain across a larger area of Oklahoma Saturday night and Sunday morning with sleet across northwestern Oklahoma in the deeper (3,000 ft. to 5,000 ft.) colder air. Over the course of Sunday morning and afternoon, the column of air at or below 32°F will deepen across the state. As it does so, precipitation will transition from freezing rain to sleet with snow beginning to mix in across northern Oklahoma. This process is going to be extremely difficult to pin down with any high level of confidence right now.
While ice and sleet accumulations look light right now, it won't take much to result in slick and hazardous traveling conditions across the state on Sunday. Ice accumulations should remain under 0.25" with sleet accumulations under 0.5". REMEMBER, these amounts are likely to change. I'm concerned in a bump upwards, because we will be dealing with a very saturated air mass.
Depending on the evolution of the mid-level low pressure system, and if enough moisture is left in place, accumulating snowfall is possible north of I-40 Sunday evening. 1" to 3" of snow will be possible along and north of I-40 from Oklahoma City (less) to Ponca City (more).
I'll have additional, intermediate updates out this afternoon and evening on Twitter.
Stay with News 9, we'll keep you advised.