More than a foot of snow is forecast for the high country of the San Juan Mountains, according to the National Weather Service in Grand Junction.

The weather agency has issued a winter storm watch for the northwest and southwest San Juan Mountains, which includes the towns of Rico and Silverton, for late Thursday to late Friday night.

Snowfall will start at high elevations above 9,500 feet, but snow could accumulate at lower elevations starting Friday as a cold front moves in.

This storm is expected to drop 6 to 12 inches of snow, with localized amounts up to 15 inches, the National Weather Service said.

The National Weather Service warns that difficult travel conditions are likely during this storm. Wind gusts could reach as high as 45 mph, causing areas of blowing and drifting snow.

Looking beyond the next couple of days, Southwest Colorado could be in for a drier-than-average winter because of a developing La Niña weather pattern, said Cortez weather watcher Jim Andrus.

The weather service has reported that a weak La Niña weather pattern is forming, characterized by cooler-than-average temperatures in the equatorial Pacific.

The phenomenon tends to generate more snow in the Pacific Northwest and drier conditions in the Southwest. It is the opposite of El Niño, where Pacific ocean warming typically generates more storms across the Southwest.

“It could be a warm, dry winter,” Andrus said.

According to the U.S. Drought Monitor, western Colorado is in the abnormally dry category. Southeast Utah and northeast Arizona are slipping into the moderate drought category, Andrus said.

The warmer and drier weather pattern of La Niña appears to be emerging locally.

As of Nov. 3, Snotels measuring mountain snowpack are showing 38 percent of normal for the combined San Miguel, Dolores, San Juan, and Animas basins. Statewide, snowpack is at 59 percent of normal.

jromeo@durangoherald.com