I don't want to alarm anyone but it looks like there is a chance for rain and (believe it or not) snow Saturday night in Tulsa and Prairie Grove, AR.
The good news is that it looks like everything should be cleared up on Sunday. I don't think there is any reason to panic, but it is worth staying current on the forecast. If nothing else, be sure you bring enough clothes with you.
At Primavera and Hell's Kitchen I found myself in 30 degree temperatures wearing arm warmers and knee warmers. I was shivering as I waited for the race to start but once the race got going I never thought about the weather again. Truth is, it is probably a good thing I didn't dress any warmer than that.