Assuming all other things being equal, is a flight from point A to point B likely to be more turbulence in the evening, vs. first thing in the morning.

Flying in several weeks from NYC across the Rocky Mountains. Flown this route a handful of times, always after 4p.m. Always turbulent.

I read that air, weather, jetstream, etc "kicks up" throughout the day from the time the sun rises so that a earlier flight is more likely to be smooth.

Is that true, again assuming all other things being equal?