No, no!

Those would standing lenticular clouds and mark mountain wave. Glider pilots love them, and have climbed as high as 51,000 feet using the associated lift.
While it's true you often have to climb through turbulent rotor to get to the smooth laminar lift, once in the smooth stuff the air is as glass while you are climbing typically at 1,000 to 2,000 feet per minute with no sense of movement save the muffled hiss of the frigid air outside.
Winds near 18K will typically be 40 to 80 knots, so you can go nose into the wind and stay stationary over the ground or even move backwards - - though it is mildly disconcerting to have the moving map (track up) flip around backwards. Unless you have an ATC approved "wave window" open, you have to plan ahead when nearing 18K. You most likely can't just nose over to avoid busting Class A, as you'll reach VNE and still be going up!
Great fun. However, if you climb too fast you can get surface cracks in the glider finish, as the outer skin cools very rapidly causing it to shrink while the spar and inner structure are still relatively warm.
bumper