J.R Orograghic rain explain

Orographic rain usually starts at a mountain range. The air mass rides along the ocean but when it hits the mountain its is forced to redirect upwards. As the air heads up it starts to cool and condensed into clouds.
Soon when the water becomes too heavy for the cloud, it will release
some of the water making precipitation or rain. As it falls most of the
precipitation will land on the windward side (closest to the ocean) and will
become moist and bloom with vegetation, whilst the other side will get only
a little and become dry.