Night turns to first light, then turns to dawn as I check the approaching sunrise. A bank of clouds is spread across the sky, but--importantly for sunrise or sunset colors--they do not extend completely to the horizon and beyond. What I call "the slot" is present. It's a gap at the horizon tall enough for the almost-risen sun to shoot through and reflect off the undersides of the clouds. Just right.
In this particular sunrise photo, the intense golds at the far horizon moderate to rich, deep reds in the middle ground, and in the foreground we can see up into the clouds, with the almost unlit dark grays adding to a feeling of depth.
Photo location: Montgomery County, near New Lebanon, Ohio.