Cinematic 8K 7680×4320. Rain is liquid water in the form of droplets that have condensed from atmospheric vapor and then become heavy enough to fall under gravity. In mountainous areas, precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation which forces moist air to condense rainfall. Weather sky atmosphere nimbus rainy rains wet falls rains overcast approaching storm stormy dark gray depressing gloomy dreary cumulonimbus stratus nimbostratus overcast microburst downburst squall curtain of rainy