I put a plant in flowering six days ago, when it was 35.5 inches tall (counting the pot). Now it's around 44 inches tall, so almost 9 inches of growth in 6 days. They can double or even triple in size when you flower them. Double is more my experience. I'm kinda scared my plant is going to get TOO big, can barely stuff it in a closet now as it is, and it'll probably grow an inch a day for a while yet.

As for yield, nobody can really predict that, as there are just too many variables. But you have good lighting, so it should be quite decent.