Atmospheric River Triggers Winter Storm Warnings Across 11 US States

Atmospheric rivers have been lashing the Pacific Northwest of the United States, prompting winter storm warnings for 11 states, with more heavy rain, snow, and strong winds predicted to follow in the coming days. An atmospheric river is a narrow space in the atmosphere that transports significant amounts of water vapor. When they hit land, the vapor is released through rain, snow, or a combination of both. According to the National Oceanic and Atmospheric Administration, atmospheric rivers can vary significantly in size and strength. On average, they carry roughly the equivalent of the water flow through the mouth of the Mississippi River. More powerful ones can transport up to 15 times more water vapor....