Good luck Paul. Anything extra you can do to secure the observatory? Mine survived the 115kmph winds of the 2015 East Coast Low, and no water got inside.
I usually bring all the equipment into the house during a big weather event, just leaving the mount head on the pier under a big towel and plastic bag (just in case). I duct tape over the front flap on the slide off roof if I have time. Roof tie downs double checked and track locks engaged.