ALT WHAT WE KNOW: Continued very cold temperatures will blanket the eastern half of the U.S. into next week. A high-altitude disturbance will dive out of Canada Thursday and deepen across the East by Saturday, leading to a strong surface low-pressure system. This surface low interacting with the very cold air mass will result in widespread heavy precipitation. WHAT WE DON’T KNOW: The placement, strength, and timing of the disturbance from Canada. The timing, track, and strength of the surface low which will determine the precipitation type (rain/snow/mix) and how much precipitation occurs onshore. The impacts to travel and infrastructure due to snow and wind.