As millions of Americans hunker down for the winter storm, 19 states and Washington, D.C., have declared states of emergency.

That uncertainty is not unusual at this early stage. Forecasters rely on a blend of weather models — computer simulations used to predict future conditions — and they are more confident in a forecast when most of those models are consistent with one another. The closer the storm is, the more confident forecasters become.

How many school closings are there for Monday? What are the road conditions like right now? What about parking bans or snow emergency levels in your county? We're following real-time updates throughout the wintry weather with everything you need to know.

The system that would fuel the snow may not even form until Saturday, resulting in low confidence in the forecast for New Jersey, the weather service said.

While some additional snow is expected to fall Monday, frigid conditions will be the primary concern in the coming days.

Tennessee’s winter storm death toll rose again Tuesday night and includes the first fatality in East Tennessee. The Tennessee Department of Health (TDH) has now confirmed eight weather-related deaths in the state over the past few days.