It's attempting to describe chaos. Chaotic systems are highly sensitive to very small changes in their initial conditions; small changes in the initial state 'propagate' and result in much larger changes in later conditions/states. Most famously, it's used for meteorological modeling. Here, they're talking about meteorological features: dust devils, squalls, and hurricane (increasing in scale). Turbulence is also an example of chaotic flow ( i.e. they say 'turbulent features'). A 'cascade' can mean a waterfall, but generally it can describe some kind of linked spontaneous process that advances over time, i.e. like water flowing down a waterfall, dominoes falling, etc.