My guess is that no, your flights will not be ontime. The worst of the storm is supposed to occur overnight, and it’s likely if your flight does depart that you’ll arrive to an airport that is struggling to operate at all.

More to the point, absolutely nothing will be happening in Seattle. If you don’t mind me asking, what are you coming up here for? If it’s some sort of event, it will probably be cancelled too - almost everything I’m aware of happening tomorrow is postponed and most businesses have proactively closed. You may also find you’re stuck at the airport if you do make it up here - most methods of transportation will likely shut down, possibly including the light rail since it mostly runs at surface level.

If you really do need to be here and plan on renting a car, may I recommend the loss damage waiver?