With cold air locked into most of the Midwest, Central States, Northeast, and New England, a new system will complicate matters as far as some frozen precipitation and hazardous driving conditions.
As the return flow helps funnel up moisture from the Gulf of Mexico, we will see this system start to develop on the rear side of high pressure. Tomorrow late morning and early afternoon, light rain will develop across portions of Texas and Oklahoma; then it will drift north into Kansas. Here we start to see some issues.
As far as light snow, mix, and freezing rain, light rain will start to overwhelm cold air at the surface, creating a treacherous situation.
Light mix and/or ice will finally shift to rain in Kansas; cold air will remain locked into Nebraska, Iowa, and upper Missouri to provide the danger for a protracted event in terms of light snow, light mix, and freezing rain tomorrow evening and overnight.
Big issues can be brought on by little ice, hence the National Weather Service has issued winter weather advisories for eastern Nebraska, most of Iowa, and northernmost Missouri. Regarding advisories, we also see extreme southeast South Dakota and southwest Minnesota mixed.
We could see some snow and ice throughout sections of Illinois and Indiana on Saturday; then eventually into areas of Pennsylvania and New York Sunday night before shifting to rain as that system strengthens and progresses to the east/northeast.