A quick update:
The major system continues to move across the state this morning with blizzard like conditions being reported in many locations across central and northeastern OK. The colder air also continues to move across the region with north winds from 20 to near 40 mph creating wind chills from zero to -15.
The snowfall accumulation forecast may come up slightly in some locations due to the enhancement from thunder snow. Amounts from 9 to over 13 inches will be likely with locally higher amounts possible. Additional snowfall is developing across southwestern OK as the upper level system draws closer to the region. We'll be updating the accumulation forecast around the 10am to 11am hour. Some higher totals may be likely in a few spots.
The arctic air mass will slide southward with very cold air remaining entrenched over the area through Friday. Morning lows will be near or below zero by Thursday morning with daytime highs in the teens.
EURO and GFS data are not in phase regarding the next system.
EURO brings a fast moving boundary across the area Saturday with no precip, while the GFS brings an upper level wave across the area Sunday into Monday with a chance of some snow showers. The EURO also hints at another very cold arctic air mass entering the area Monday evening or early Tuesday. I have basically sided with the EURO for the later period, but have added a slight chance of snow showers Sunday into Monday.