A persistent drought continues in the Four Corners, and residents should expect more of the same, weather officials report.
For the Cortez area, precipitation is at 44% of normal for the year, said Jim Andrus, a weather observer for the National Weather Service.
As of November, Cortez had received 5.18 inches of precipitation for the year, he said. The average year-to-date precipitation is 11.69 inches by the end of November.
October saw just .02 inches of precipitation, or 2% of the 1.3-inch average, Andrus said. November saw just .34 inches, or 32% of the 1.06-inch average. December is at zero inches in the first week.
A strong La Niña weather pattern has helped shift the jet stream farther north, which keeps storms from the Four Corners, officials said.
“It’s the strongest La Niña in 10 years,” Andrus said. “Even when we do get storms that dip down our way, they are weak at most.”
A La Niña weather phenomenon is characterized by below-average sea temperatures in the Equatorial Pacific, which decreases the chances of winter storms tracking over southwest Colorado.
A National Weather Service advisory states “La Niña conditions have developed in the tropical Pacific and are expected to persist through the winter.” The advisory is issued when conditions are expected to continue.
The long-term forecast for the Four Corners is below-normal precipitation and above-normal temperatures, said Norv Larson, a meteorologist with the National Weather Service.
High pressure and a dry air mass are generally blocking storms from reaching and forming in the area, he said.
This week, a couple of storms from the Pacific Northwest could reach far enough south to graze the area. On Thursday, there is a 20% chance of showers in Cortez and Durango, and on Friday there is a slight chance of snow showers.
Snowpack is well below average in Southwest Colorado.
Snotel stations in the mountains that measure snowfall, show the Dolores and San Miguel river basins are 48% of normal as of Dec. 7.
The Animas River Basin is at 38% of normal, and the Gunnison River Basin is at 53% of normal.
The Telluride Ski Resort reports a 21-inch base, and Purgatory Resort has a 16-inch base.
As of Dec. 3, Southwest Colorado and most of the Western Slope were in “exceptional” drought, the worst level out of five, according to the U.S. Drought Monitor. Most of Utah and Arizona also were in exceptional drought.
jmimiaga@the-journal.com