Option 1: Because he is an ass.
Option 2: Because he misses his daddy. The same daddy who never feeds him, kicks him off the bed, doesn't scoop his litter, and once demanded that we "get rid of the cat" because he scratched the leather recliner, but who still manages to get more purry kneady love from said cat.
Option 3: Because a moth the size of a pterodactyl has invaded the house, and the cat believes he will be able to meow him down from the wall and thence munch on him.
Option 4: Because it's fun to wake his canine brothers and sister up early. They are too dumb to realize that it's not actually time to be AWAKE and GET FED and GO OUT IN YARD TO BARK AND PEE.
I'm thinking it is a combination of all four options that inspired today's early morning howling. There really was a moth in the house (flew in after the final dog walk last night) and it really was enormous. But Rocky also ALWAYS starts his early morning wake up calls when CPM is away. It's ridiculous.
I can guarantee you, cat, your father does not miss you ONE BIT.