Prognosis... Strong storm system will be ejecting from the Rockies on the 20th-21st. As the storm system moves east, the subtropical jet stream and Pacific jet stream will merge into a single, powerful jet stream that will be centered over the outlined region. Current thinking is that the abundance of moisture and strength (albeit weakening) of the storm system will provide a base for severe weather on the 21st. Tornadoes and damaging winds would certainly be possible, but model uncertainty forbids me from making any definitive conclusions on threats for this day.
I will have more updates in coming days.