Assuming the clock is running normally and I have not mixed records with any game. Important note: For those of you that haven't played Emerald, many days there are no outbreaks. I already had two people mess up on their logic.
Every time the player wins a battle, there is a ~0.5% (0x147/0xffff) chance that the game will generate an outbreak. This does not apply to the player's first battle, the Wally catching tutorial, link battles, e-Reader battles, the Safari Zone, or the Battle Tower/Frontier. After an outbreak is generated, the television program announcing it will appear the next day. Once the television program has been watched, the outbreak becomes active.
source That probably explains why I could never get one.
There are seven slots. One can be skit. One can be nuz. Two can be blank. Three can be Seedot.
Therefore 1/7 for each with no record mix.