What is the biggest hazard associated with a thunderstorm?

The biggest hazard associated with a thunderstorm is wind shear. Wind shear refers to the sudden change in wind speed and/or direction over a short distance, which often occurs in the vicinity of thunderstorms. This phenomenon poses a significant risk to aircraft during takeoff and landing phases, as the aircraft can experience abrupt changes in lift and performance. The presence of downdrafts and microbursts can lead to severe turbulence and loss of control, making wind shear a critical hazard to be aware of when flying near thunderstorms.

While turbulence, lightning, and heavy rain are indeed associated with thunderstorms, they do not typically present the same immediate threat to an aircraft's safety as wind shear does. Turbulence may cause discomfort and some control challenges, while lightning, although dangerous, generally does not impact aircraft performance when the aircraft is adequately equipped. Heavy rain can reduce visibility and cause hydroplaning on runways but is not as sudden or severe as the effects of wind shear.