From the start of air flight, pilots have known the danger involved when encountering a thunderstorm. Even with the sophisticated on board and external guidance equipment in use today (primarily radar), wind shear and turbulence in conjunction with lightning and hail make thunderstorm penetration a very hazardous venture. Pilots still apply the axiom of avoiding contact with the thunderhead if at all possible. Any approach into a thunderstorm will experience sudden changes in wind direction and speed (shear) and turbulence.
The perils of a thunderstorm
1. The aircraft encounters a strong headwind and sudden downdraft, which decreases ground speed, resulting in turbulence and the need to "correct up" to maintain glide path.