What is the biggest hazard associated with thunderstorms?

The biggest hazard associated with thunderstorms is turbulence. Thunderstorms can create severe and unpredictable turbulence due to the intense and rapidly changing winds within and around the storm. This turbulence can manifest in various forms, including updrafts and downdrafts, which can pose a significant risk to aircraft. Pilots flying in or near thunderstorms may encounter sudden changes in altitude and airspeed, making it challenging to maintain control of the aircraft.

While lightning strikes, heavy rainfall, and strong winds are also notable dangers associated with thunderstorms, they do not have the same immediate and chaotic impact on aircraft performance as turbulence does. Lightning can strike aircraft but is generally not lethal due to the protective design of modern aircraft. Heavy rainfall can reduce visibility but is often manageable with appropriate pilot techniques. Strong winds, while they can affect flight dynamics, do not involve the same abrupt changes in airflow that turbulence does. Thus, turbulence is highlighted as the primary hazard due to its potential to affect flight safety most directly and drastically during thunderstorms.