ShmoopTube

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[Coop and Dino singing]

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There are tons of upsides to living near a mountain range... [Mountain range and man waterskiing]

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Winter skiing, summer hiking, mountain biking, rock climbing, snowboarding, dressing up in

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Wookie costumes and tricking people into thinking you're a peaceful yeti living in the hills…

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…Maybe don't do that. [Lion and Yeti in museum display]

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You don't want to be captured and stuck in a natural history museum.

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But if you happen to live on the side of a mountain range – specifically, on the opposite

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side of the ocean – then another plus for you is you probably don't get a whole lot of rain.

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Though it also might mean you live in a desert…in which case, a little rain once in a while [Man laying on the desert floor]

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probably wouldn't hurt.

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Anyway, what we're talking about here is something called the rain shadow effect.

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What this effect describes is the dramatic difference in rain between two sides of a

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mountain range – specifically, how one side gets plenty of rain, and the other side gets,

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well, not so much at all… [Rain falling on one side of mountain]

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Man…what a rain hog.

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But why does this happen?

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What conditions do we need for the rain shadow effect to occur?

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Well, first, we need a mountain range.

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That part should be pretty obvious since mountains are in the definition. [Goat on a mountain side]

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Then on one side of that mountain range, we need an ocean.

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Lastly, you need wind blowing from the ocean towards the mountains. [Wind blows Coop over into the ocean]

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Alright, now that we've got all our prerequisites in order, let's get to makin' a rain shadow.

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We've broken it down into three easy steps:

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Step one is all about evaporation.

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When water from the ocean evaporates, we get moist air. [Ocean water evaporates]

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This moist air is then pushed towards the base of the mountains by the wind.

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Step two is all about rising.

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When the water moisture in the air meets the mountains, the wind blows it against them.

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And since it can't exactly magically travel through the mountains, it tries to go over

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instead.

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So, this water moisture gets pushed up, rising to the top of the mountains. [Water moisture pushed up the mountain]

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And as it rises, it cools, becoming clouds.

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So now we've got clouds, but what else is happening?

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Well, the air is cooling off, and cooler air can't hold as much moisture as warmer air.

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So as this air continues to cool, rise, and travel over the mountains, it has to ditch

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some of that moisture. [Cloud becomes darker and begins to rain]

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That ditched moisture comes down as rain, which just happens to be step three.

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This effect is why many places that are in between a mountain range and the ocean, like

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Vancouver, Canada, get plenty of rain.

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They're located on the side of the mountains called the "windward side" since the wind

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is blowing at it.

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So once all of this wind makes its way over the mountain to the leeward side of the mountains, [Wind moves to leeward side of mountain]

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there's pretty much no moisture in the air left.

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And that right there is what's called the “rain shadow,” created by, you guessed

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it, the rain shadow effect.

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The rain shadow effect explains why a place like San Francisco, California has so much [Car blowing in the wind in San Francisco]

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more rain than a place like Reno, Nevada.

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Neat, huh?

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And hey, don't worry, Reno.

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You've got other cool things.

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Like…the National Automobile Museum!

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Maybe someday, we'll make a video about that. [Woman standing in National Automobile Museum]

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