T​his segment originally appeared in today's edition of the Morning Brief newsletter. Sign up here to get weekday updates from The Weather Channel and our meteorologists.

While the more common definition for “plume” refers to a feather, meteorologists have picked up the word and use it rather frequently when talking about moisture (or water vapor) that results in rain and snow.

This week, a series of atmospheric rivers are expected to move onshore along the West Coast. When you hear us talk about them, many times we will say “an atmospheric river is bringing a ‘plume of moisture’ to the West Coast.” That’s because an atmospheric river is like a firehose in the sky, bringing tremendous amounts of precipitation to wherever it is taking aim.

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These rivers in the sky can stretch for more than a thousand miles north/south and can move more water than the Mississippi River in a single day! They are responsible for 50% of the precipitation in the West, so the rain is beneficial - but if they are too strong, then atmospheric rivers can result in devastating flooding and landslides.

M​ORE: Read how climate change is causing atmospheric rivers are shifting northward, here.