Endura FlapLarge Door Mount - White Double Flap 10" x 18" pet door

I live in an extreme windy climate. The wind blows in my current dog door. Does this door stay shut during high winds?

Has anyone had issues with rain getting inside? we live in hawaii and want to install this on our ext door but we get a lot of rain. single or dbl?

Does it have a panel to close the door so pets are locked in or out?

I'm not sure if i need a double or a single flap ? what kind of criteria determines which one i need ? don't all doors need double flap ?