Steam weekend deals

Hey, does anyone know if there is a way of knowing what the steam weekend deal will be before the actual weekend because I want to buy some stuff on their but someone said that their is going to be a big half life deal on soon but I have no idea when this will be and I dont really want to buy something and then have it 50% off in a couple days.

Most of the time its usually on Thursday or Friday that Steam announces what game is going to have a price reduction deal for the following weekend :)