The polar vortex is a system of wintertime winds.

Rainforests have their own perfect system for ensuring their own survival; the tall trees make a canopy of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, intense dry heat from the sun and strong winds.

Because the winds at that level are pretty strong, the clouds aligned parallel to the direction of wind flow, in “streets” curving along with the flow of the high-pressure system.