Question

why rainshadow areas generally dry

Answer 1

Because they don't receive seasonal rainfalls as the mountains restrict the monsoon winds to cross them , making them to shed rain along the windward side.

Hope it helps!

Answer 2

ANSWER:

   Rain shadow is a condition of the places which are at the mountain base or at the base of a mountain range, the large range of mountains usually does not let the rain clouds to pass through it and it results in a lot of rain in the mountain range but the place at the mountain base is deprived of the rain and it remains dry throughout the season.

   Tamil Nadu in the southern part of India is one such state which faces this condition.