States all over the western United States is struggling with record low snowpack levels in the middle of the winter season. A snowpack crisis is looming that could mean a drier and more fire-prone summer as states race unsuccessfully to agree on terms for sharing water in the Colorado River basin, which is the source of water for 40 million people in seven states in the West.
“Unless there is a truly miraculous turnaround” during the rest of the winter, says Daniel Swain, a climate scientist at the University of California Agriculture and Natural Resources, low snowpack “could worsen both the ecological and political crises in the Colorado River Basin and then cause truly unfavorable fire conditions in parts of the West.”
Data Data provided by the U.S. Department of Agriculture show that snowpack in nine Western states remained at less than half of normal levels as of February 12 – one of the lowest levels seen in decades. It is common for a particular river basin or petite area in the West to experience low snowpack at this time of year. What’s worrisome, Swain says, is the breadth of the snow drought, stretching from lower Washington to much of Arizona and Up-to-date Mexico and extending as far east as Colorado.
“The numbers are really, really bad,” Swain says. “If it were November, they might be less significant. We are not in November, we are approaching mid-February. The normal numbers are quite high. If it is half of them, it means that in absolute terms the deficit is large.”
As much of the East Coast froze over in the first weeks of the year, many western states are experiencing some of it the warmest winters on record: : Parts of Colorado Earlier this week, temperatures reached almost 80 degrees Fahrenheit. Although precipitation remains steady in many states – there was even catastrophic flooding in parts of Washington in December – in many areas it is simply not chilly enough for snow to fall or remain snowpacked.
Test released last year Dartmouth researchers found that climate change has reduced snowpack in the Northern Hemisphere over the past 40 years. The snowpack deficit has worrying consequences for the West for the rest of the year. Forests with low snow cover droughty out faster and are less resistant to fires when the scorching season arrives. (Forests damaged by fire may, in turn, be less prepared to maintain snow cover; some recently tests found that in areas that have recently been burned, snow melts faster than in other places.)
Most water supplies in the West, including the key Colorado River basin, occur in winter. The snow cover that accumulates during the chilly months melts in spring; in years when snowpack levels are vigorous, this water flows into streams and reservoirs. Current conditions pose a threat to this vigorous.
“In some places we’re not experiencing a traditional drought — we’re experiencing a snow drought where rainfall is close to or above average, but the record warmth has actually completely decimated the existing snowpack,” Swain says. He said the warmth in other areas “caused precipitation, which in some cases was quite heavy, to turn into rain even at an altitude of 2,000 to 2,000 meters above sea level.”
Swain says it’s still early enough in the season that some areas could experience significant storms to support replenish snow levels. “The problem is that we’ve accumulated such a large deficit right now – even if snowfall amounts are close to or slightly above average over the next few weeks, they may just keep pace with normal accumulation throughout the rest of February without actually erasing the accumulated deficit,” he says.