Raid,
Maybe this will help maybe it won't but if it were me and I were staying [at this point you don't have a choice] I would put it where it is as protected from the wind and as far away from trees and other anticipated debris as possible. I would place wide outrigger pads down and lower the outriggers to the pads but only to the point of taking some bubble out of the tires but still leaving weight on the tires. This will give you as much surface area for stability as possible. if you can I would also drive rebar or some other substantial rod into the ground and strap from the rod to the frame to use as hurricane straps, just like they do for double wide trailers. I would also fill ALL of the water tanks (fresh water, black water and grey water) simply to add weight to your bus at the lowest point. Assuming you properly secure it and the wind doesn't flip it your biggest issue will be debris which is what causes the greatest damage in any hurricane so if you can provide any sheeting protection such as ply-board and secure it around the bus with straps so it doesn't become debris you will have done all you can.
Some might disagree with filling your black and grey water tanks with fresh water thinking that you may need those for use after the storm if your home looses power. As soon as the major winds subside but while it is still raining go outside and open your black and grey water handles to dump them in the rain right on the ground where it is sitting. Remember this is all fresh water and any residue that was in the black tank will be diluted by the rain - no different than a drain field.
Good luck and if you think about it post an update in a couple of days to let us know how you fared.