- Strong lee cyclogenesis over eastern Colorado with cold high pressure to the north and northwest
- A strong intervening pressure gradient with strong surface winds across Wyoming and the Dakotas
- Heavy precipitation rates
Check out the GFS forecast for 0600 UTC (0000 MDT) 4 October through 0600 UTC (0000 MDT) 5 October. Yeah, those are some big precipitation totals with some very strong winds.
It's not going to feel like October 4th in this part of the world tomorrow. This is a very serious storm with winter storm conditions about as bad as they can get.