“God thunders wondrously with His voice . . . For to the snow He says, ‘Fall on the Earth,’ likewise to the downpour, His mighty downpour.” — Job 37:5-6
The world’s largest rivers include the Amazon, Nile, Yangtze, and Mississippi. But there are also rivers you’ve probably never heard of. These “rivers of the sky” aren’t actually on Earth. But they’re potentially devastating—and yet vital—currents around the world.
Atmospheric rivers (ARs) are relatively long, narrow plumes of moisture that exist in the atmosphere. They’re part of the Creator’s ingenious plan to move water vapor from the steamy tropics to drier regions of the world, farther from the equator. The largest ARs can carry water vapor equal to 15 times the amount of the water flow at the mouth of the mighty Mississippi River.
When ARs make landfall, they often release vapor in the form of rain or snow. An AR that stalls over a drainage basin (an area that collects rain and drains into one outlet, like a river or lake) can produce extreme rainfall, strong winds, mudslides, and damage to life and property.
In 2019, scientists devised a scale to classify ARs, similar to the wind scale used for ranking hurricanes. The scale measures both benefit and hazard using five levels: “weak” to “exceptional” in strength and “primarily beneficial” to “primarily hazardous” in impact.
Although some large ARs cause trouble, most simply provide much-needed rain or snow to refresh a region’s water supply. One strong atmospheric river brings moisture from the Hawaiian tropics to the U.S. West Coast. It is quaintly named the “Pineapple Express.”
ARs are extremely important in the global water cycle. Their contribution to an area’s snowpack can help water an entire area throughout the dry summer months. They’re closely linked to both water supply and flood risks—particularly in the western United States.
In November, back-to-back-to-back storm systems linked to ARs threatened parts of western Washington and British Columbia, Canada. With snow added to the mix, flooding became even worse. There were no breaks between storms, so the region’s soggy ground couldn’t dry out.
During the fall AR weather event, rivers inundated towns, landslides choked roads, and a long-dried-up lake re-emerged. In northwest Washington’s Whatcom County, officials say costs from mudslides, road collapses, and property damage could reach as high as $50 million.
“One hundred years ago there was a Sumas Lake,” says meteorologist Johnson Zhong. “Then they pumped the water out to make good farmland. It has been farmland for the last 100 years, and now it’s a lake again.”
Why? God’s wisdom and creativity are awe-inspiring, so we study His creation in detail to learn more about Him as well as to manage the creation for good.