If you're coming from east Montgomery, take the Mulberry exit. Turn right on Mulberry, go one block and take a left on Holly St. I believe the park road is one-way. You should enter at the northern most entrance and circle the park. The planetarium is near the exit at Jackson Hospital.
Parking is available across from the planetarium.
Rick said that the event will go on even if cloudy, in which case, we will have the scopes set up in the lobby of the planetarium. It sure would be nice to have a few more of these to show. Some of the big guns would certainly be impressive for the visitors. Let me know if you can help. Sounds like we'll have a pretty good representation of telescopes for the event.