1- Bands A: math pattern noise node **Sine Waves** Wavelength set to 1/0/0 followed by an **Absolute** filter node. Other nodes work as well, like Water Wave (without an **Absolute** filter node).

2- Bands B: A second math pattern noise node Sine Waves set to 1/0/0 again followed by an Absolute filter node.

3- Above the 2nd Sine Waves node I placed a Rotation&Twist math node, and set z-Rotation to something like 15 degrees.

4- Perlin Gradient Noise, followed by two nodes, which filter the values so they reach exactly from 0 to 1. The output of this branch feeds a Blender node, which blends between Bands A and Bands B (rotated 15 degrees on the z axys).
A Blender works as expected when its extracted blend parameter is fed with values between 0 and 1.

5- This branch applies turbulence to the bands. A regular Turbulence node would do the job as well.

Note: The reason why I am using two Sine Wave nodes with one slightly rotated is because this "double bands" phenomenon can be observed over and over again in real life clouds (and sand ripples).

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