I was writing my last post when you posed the question about creating their own environments that I touched on.
Yes, if they are big enough and strong enough, they can. As I alluded to above, Gilbert not only created its own environment, but altered the weather pattern for weeks to come if memory serves. Without seeing maps from that time, I recall Gilbert hitting NE Mexico, and getting lost in the mountains, but the high aloft that went with it, remained over the GOM for several weeks, and cleaned things out for a while. If anyone remembers this differently, feel free to set me straight on that, but that is what I remember. Also, Gilbert was the strongest ever, and its pressure dropped to 888 mbs. in addition to its huge areal coverage.