The winter storm is unfolding as expected with a period of sleet and freezing rain changing to all snow across most of central and northeastern OK. The upper air profile still indicates a pocket of above freezing layer at 5000 ft across east central and southeastern OK as I post at 2am this morning. This layer will continue to slide eastward with time. But for the next few hours locations across southeastern and part of east central OK will continue to have a freezing rain and sleet threat. Some moderate icing is likely across southeastern OK into west central Arkansas for the next few hours.
Snowfall rates should increase across south central and central OK as additional moisture begins moving northward into the state. Colder air at the surface will also continue to move southward with gusty north winds at 15 to 35 mph creating blizzard like conditions across portions of central and northeastern OK. Temperatures will continue to drop into the lower teens by this afternoon with dangerously low wind chill values.
Snowfall accumulations are likely in the one foot category across portions of central to northeastern OK with some locally higher amounts. The period of sleet earlier this morning will act to slightly limit the overall snowfall total potential but significant amounts of snow continue to be forecasted for portions of the area. Locations south of I-40 will see lower amounts from 6 to near 8 inches with some higher totals in some locations. This is due to the proximity of the warm layer aloft early this morning and the impact of more freezing rain and sleet compared to all snow.
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 a the EURO for the later period, but have added a slight chance of snow showers Sunday into Monday.