Dave,
Concerning the most likely scenario for any given day in mid August, I concur with Scott.
But realize that in August a storm can drop by at any time (often unannounced) and leave a few inches of the snow on the trail for a day or two. Typically, this will require hiking several miles in fresh snow (on top of dirt and rock) on the most challenging part of the Trail (Zone 4).
Many are envious you got such a great day in the lottery. Enjoy!
Jim