Highway 1 between Chilliwack and Abbottsford in BC. That area is called the Sumas Prairie and it can really surprise you there sometimes.
The other highway is one I seldom get to ride but I don't think I've ever been on it without a stiff breeze blowing. That would be highway 3 from Fort Macleod in Alberta to Fernie in BC. I guess they put those wind gernerators in that valley for a reason.

Two summers ago, I was returning from visiting my girls in Calgary. On some parts of that road I felt like I was turning one big corner I had the bike leaned over so much. I know what you mean by it feeling like those tires are going to be blown out from under you. I think thats about the worst wind I've ridden in for years.
There might be a few on this site that can confirm how windy it gets down in that part of the province...