By analyzing the upper atmosphere wind flows, it has been discovered that the high altitude, slow, drunkenly meandering undulations of the flow patterns transporting heat across the planet. This pattern is referred to as a Rossby wave, named after the Swedish born, American meteorologist called Carl-Gustav Arvid Rossby.
The influence on the weather from this undulating Rossby wave is significant and causes droughts and high temperatures in the eastern part of the North American continent.
Rossby waves are a phenomena as a result of potential inertial effects influenced by the Coriolis force and pressure gradients.

There also exist other types of waves, including presences in the ocean basins at the thermocline and similar places.
For more information on Rossby waves in the atmosphere or ocean see below references.