So this post is actually about my dad's yard...I told him there were some super knowledgeable people here that might be able to help out. I'm pasting the email he sent me explaining the problem and the link to pictures

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My one acre yard just in South Mississippi has looked better this summer than almost any other summer over the past 24 years I've lived here. Part of that I'm sure has been that we've generally had enough rain this summer. But, just in the last week, these big brown spots have appeared where most of the grass looks dead. I've attached a link below to 20 or so photos. The first group of photos show the brown spots. The next group shows some kind of weed that seems to be doing fantastic. Maybe the weed was always there, and I just didn't notice it when the grass was healthy. The last group of photos shows some still healthy looking sections of the lawn.

I don't recall such huge brown spots in the late summer except in years when it's been real dry. What's especially perplexing is that it's looked so good all summer, and now it looks worse than it has in years. The whole yard used to be an old cow pasture. It's generally a mixture (at least I've always thought) of centipede, carpet grass, and just enough bahia to annoy me. Any diagnosis and advice that you or your turf-expert colleagues could give me, I'd appreciate. Here's the link to all the photos.

Pictures are at

https://www.flickr.com/photos/84863924@N00/sets/72157670516117263/