St Louis is starting to come in and Trump is maintaining his lead. I think we may be getting closer to a narrow call for Trump.
If the pattern from other southern states (and Kansas City) is followed, late precincts should be better for Cruz than earlier ones, though I'll concede it doesn't look too good.
First off, Missouri is not southern, but the only things out now are about 55% of St Louis City, all of Perry County, and a little bit of Jackson County (Kansas City). Trump has a 3,000 vote lead, so I think his lead, while not safe, is looking better and better.