WOW!!!!
certainly POSSIBLE, but not usually prolonged. I think it depends on where you are (as far as how far out you are) and how much you have (or had) to lose to begin with.
there were a couple weeks where I was losing 2-3 pounds per day.... then like someone threw a switch, I'm now losing 1-2 lbs every 2-3 days. still excellent, as long as it's still coming OFF though.
good job... wishing you continued success.