<human>: I've been planning this out for a while. The biggest element was for this to be a surprise. The plans for the day are for she, myself, and a friend of ours to all go to a park. She and I have been to the park many times (our first dates were there), but our friend hasn't and he needs to scope it out for a family event he wants to have later this year. 

Unfortunately I get called away for work (actually an emergency business trip, and I've planned out all those details). She still goes with our friend to the park to help, where I will be there waiting with a picnic and will propose to her there. We've already selected a nice clearing that is secluded. Problem is, it is supposed to now rain. The only idea I've come up with is to try and find a canopy to shield from the rain. And to have a lot of blankets. 

Other than that, the only idea I have for somewhere indoors would be a museum. I'm in Southern California if that makes any difference. Any ideas from anyone? I have only a few days to figure this out. It is tough since I want to keep this a surprise and don't want to ask my friends for fear of 'letting the cat out of the bag'. 

I really, really want to make this a surprise for her, yet meaningful as well. It would really mean a lot if there were any ideas to help my little feeble mind!

Can you provide a brief overview of the text?
<bot>: doing an outdoor proposal this weekend and it is going to rain. Not sure if I should change my plan entirely or try to weatherproof my proposal idea.