I, too am hearing Sam on 5 MHZ with a strong signal in North Texas.
This is almost certainly a covert "go" signal from our government.
Could be an exercize (most likely).
It's on WWV at 5 mHz because that provides a "BFO" for cheap SW
receivers. I will note the times I hear him.
Please note those you hear.

Loud 3:22:50 Z
Loud 3:23:35 Z
Weak 3:24:05 Z

Like that.
Let's see if we can do a little snooping of our own.