"Low snowpack, leftover burn scars, and abnormally warm temperatures are supercharging the atmospheric rivers hitting the Pacific Northwest."
"A long, warm plume of airborne water snaked its way from the subtropical Pacific Ocean toward the U.S. West Coast at the beginning of this month. As the so-called atmospheric river made its way north, it sucked up moisture from above-average sea surface temperatures.
When the airborne river washed ashore on December 8, it unleashed a torrential gush of water on the Pacific Northwest that didn’t let up for the better part of a week. Now, a second atmospheric river is battering Washington state, with a third likely later this week.
On Wednesday, Washington Governor Bob Ferguson declared a state of emergency and public officials issued “go now” evacuation alerts to 100,000 people. Thousands in western Canada also received orders to evacuate. Up to 18 inches of rain fell on parts of western Washington state last week, and rivers across the region burst their banks. At least 30 major roads were impassable or closed due to damage, and emergency crews conducted 250 water rescues.
“The flooding levels we’re looking at are potentially historic in nature,” Ferguson said at a press conference on Thursday."
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