The sun, moon and sky glow over Jobs Peak on Monday afternoon.
Photo special to The R-C by Steve Grabhoff.
You’d think that with two atmospheric rivers hitting the West Coast within days of one another over the weekend before Thanksgiving, Western Nevada would be sitting pretty going into the major snow months.
But the majority of the moisture either went north or south, leaving Carson Valley a dry sandbar between those rivers.
The entire Carson River basin was running 93 percent of average for Dec. 9, while the Walker is at 92 percent and the Truckee River is at 100 percent.
While the 10th wettest November on record in Northern California, there was virtually no improvement in Nevada, according to National Weather Service Development and Operations Hydrologist Pete Fickenscher.
“It’s early in the water year, so there’s always hope for change,” he said.
Several months after the prediction of a La Niña, it has yet to manifest, Fickenscher said, something that he referred to as “La Nada.”
“People are still hopeful we might see something later this winter,” he said.
La Niña is the opposite of El Niño, and both are part of the El Niño Southern Oscillation which examines surface temperatures in the Pacific Ocean. Cooler water temperatures associated with La Niña tend to bring wetter winters to the Northwest, while El Niño tends to favor more moisture in the Southwest.
“La Nada” winters aren’t always dry, with 1967 and 1993 ending up wetter than average.
However, most models are indicating there could be below average rainfall over this winter.
On Dec. 3, Fickenscher presented maps that showed the extent of precipitation from the three days starting Nov. 20, which essentially drew diagonal lines that bracketed Lake Tahoe and Carson Valley.
“It shows the highly variable nature of precipitation we see in Nevada and California,” Fickenscher said. “South of the I-80 demarcation didn’t get much at all.”
He observed that all it takes is 5-15 wet days to make up half a water year.
He said the northern moisture plume arrived after a significantly dry period where eight precipitation gauges in the Sierra showed only 1.71 inches between June and October, amounting to the 12th driest period in 104 years.
“It was an incredibly rare event,” he said. “We were fortunate we were coming into an event that had dry soils that absorbed a lot of that.”
The second atmospheric river passed south of Western Nevada in a narrow plume.
