No they don't have any covered courts, as tamus said, it's so they can put multiple matches on at the same time and save time that way when it finally clears. I'm surprised they haven't built a roofed stadium yet at the uso, both the ao and wimbledon beat them to it. They might end up being the last slam to have covered courts.
The rain is not going to last all night. There should be (hopefully) a dry patch during the early evening. The weather has called for dry patches here and there and we haven't gotten any yet. I want the women's final to be tomorrow.