A large amount of moisture from the Pacific Ocean, known as an “atmospheric river,” is headed for Southwest Colorado.
“It’s basically this strong plume of moisture that comes off of the Pacific,” said Erin Walter, meteorologist with the National Weather Service in Grand Junction. “It’s like this continuous stream, almost like a jet but in the form of moisture.”
Over the weekend, the atmospheric river dumped more than 5 inches of rain in the San Francisco area, Walter said.
Most of the moisture from the storm system will be dropped in California over the Sierra Nevada’s and the Great Basin, with Southwest Colorado getting the last bit of that precipitation on Tuesday.
“We aren’t going to see feet of snow like the Sierra Nevada’s, but we are going to see some precipitation,” Walter said.
Southwest Colorado has been experiencing warm conditions, which will be a determining factor in how much precipitation falls in the region, Walter said.
“We’re seeing snow amounts higher up Tuesday morning, and then as the system moves through, some colder air will move in behind it,” Walter said.
Towns along U.S. Highway 160 should expect around a quarter of an inch of rain Tuesday, with some areas potentially seeing higher, localized amounts of rainfall around half an inch.
“I would expect at least a quarter of an inch for Durango, Cortez and Pagosa Springs,” Walter said.
As for snow, Silverton is expected to get about an inch of powder in the city, with around 5 to 8 inches in higher elevations of the San Juan Mountains.
The National Oceanic and Atmospheric Administration released its winter outlook for temperature, precipitation and drought Thursday. NOAA said this will be the second La Niña year in a row. La Niña seasons are caused by cooler-than-average sea surface temperatures in the Tropical Pacific.
“The Southwest will certainly remain a region of concern as we anticipate below-normal precipitation where drought conditions continue in most areas,” said Jon Gottschalck, with NOAA’s Climate Prediction Center.
Southwest Colorado is expected to have 40% to 50% higher temperatures than normal, 33% to 40% lower precipitation than normal, and drought conditions expected to worsen.
“Any moisture is definitely welcomed,” Walter said.
njohnson@durangoherald.com
