Arctic air moved in Sunday night, and will hold firm for much of the week. We often lack enough cold air for snow in strong El Nino winters, and the current one is no exception. But this time it's clearly cold enough for the storm to at least start as snow through just about the entire area. And, as long as the storm tracks south of us, it's going to be hard for all of us to see a change to a wintry mix and/or rain. Some area is going to see all snow-and probably a lot of it.