Hope for a “jubilant” January, a “fabulous” February, and a “miracle” March fell flat this year. The western US, including much of California and Nevada, faces another drought year. The Drought Monitor map shows the Sierra Nevada in “severe drought” along with all of western Nevada. Worse designations of “extreme” and “exceptional” drought categories are found in portions of 8 of the 9 western states.
Truckee River: low flows ahead for spring and summer
After the summer of 2021’s extreme fires and, in much of the west, unprecedented heat, December’s storms seemed to herald an above average water year in the offing for the Sierra. But a record breaking, dry January and February ended the hope that the 200% snow pack would persist. The ides of March has come and gone. Yet, the Sierra snowpack that supports the Truckee River is just 76 and 68 percent of average in the Truckee River and Tahoe watershed today. Lake Tahoe is just 12″ above its natural rim and the very real prospect of a continuing dry spring mean lower flows into the Truckee River below Tahoe City. The traditional April 1 peak snowpack measurement becomes less relevant as climate change warms temperatures winter and summer. The lack of storms in what should be the Sierra “wet season” stretches our multi-decadal drought for yet a further spring and summer.
The timing between rainfall events stresses plants throughout the region. The decrease in moisture leads to more intense fires and dried up vegetation needed for wildlife and agriculture alike.
The research was led by University of Arizona climate scientist Fangyue Zhang. The reduction in drought busting rainfall across the southwest is consistent with climate models forecasting decreased moisture as the overall atmosphere warms due to human-caused greenhouse gas increases.
“Human activity is driving climate change.” said Colm Sweeney of NOAA’s Global Monitoring Laboratory this Wednesday according to an article in the USA Today which continued: “…the level of carbon dioxide (CO2) in the Earth’s atmosphere is now higher than it has been in at least 3.6 million years.”
Droughts appear to be lasting longer as the active winter pattern of Pacific storms shift north more frequently. This year in California and western Nevada, only one significant storm in January upped the percentage of the meager snowpack. Ultimately, the snowpack topped out around 68% for the Tahoe-Truckee River by April 1, but runoff will be less than 40% of the average due to the extremely dry soils throughout the Sierra and Nevada.