What Are The Types of Turbulence?

Turbulence is the irregular motion of an aircraft in flight due to high winds. Turbulence is dangerous due to the potential of sharp dropping and increasing of altitude and structural damage to the aircraft.

There are three types of turbulence: convective, mechanical, and wind shear.

Convective

• Caused by convective activity, the rising of air, cumulonimbus cloud formation, thunderstorms, etc. 
• Ingredients are: warm, sufficient moisture, unstable air, lifting agent (similar ingredients to a thunderstorm)
• Turbulence found below or within the clouds 

Mechanical

• Turbulence caused by obstruction to the wind flow (ie. buildings, trees, mountains)
• Wind caused by these obstructions is called "eddies"
• Common mechanical turbulence are mountain waves 

Wind Shear

• Wind shear is the sharp change in wind direction and speed in a short amount of time.
• Caused by when two different wind currents with different speed and direction converge.
• Clear Air Turbulence (CAT)
  • High altitude turbulence between the jet stream and surrounding wind currents
  • Dangerous because there is NO visual cue

• Low-Level Wind Shear (LLWS)
  • Low altitude wind shear where wind is greater than 10 knots per 100 feet in a layer over 200 feet thick
  • Dangerous for takeoff and landing