When you set up any weather, it shows how many turns left it has in the upper left corner, then disappears when it runs out. However, when gravity is up, the message never disappears even when gravity turns expire. This happens everytime. Proof:
(Sandstorm was summoned by sand stream, btw)
Also, if you use entrainment, and then the foe switches out, when the entrained pokemon comes back in has its original ability as expected, but if you hover your mouse over it, it will say it has the ability you gave it with entrainment. I'm not sure if this also happens with skill swap, but it happens every time when "entrainmenting" truant.
Thanks for your time.