How to get in on St. Arnold’s Pumpkinator preorder?

Every year I try and get my hands on Pumpkinator as soon as it releases, but I always seem to find out about it just a bit after it's announced and all the specialty bottles are all sold out by then. I know it ends up on shelves pretty reliably later, but I want to get it on time this year.

Does anyone know how people find out about it so quickly? Is there a usual time it's announced so I can be sure to log in then?