Super clearance is both online and in stores. They don't publish the super clearance details online, but do email REI members in advance of the sale. I was at the store today and they were setting up all the bins to hold the clearance gear.
I'll be waiting in line before the store opens
Edit: The details of the sale are: Any item whose price ends in .83 will be an additional half off the already discounted price. They usually run these about twice a year to clear out mostly seasonal items.
I plan to pick up a pair of ice axes, some assorted climbing gear, and a bunch of cold weather clothing.