Snow big deal
The heavy snows of winter contain a risk—that people will think the drought has ended
The question looms: Will this year’s exceedingly wet winter end the drought that has plagued the Reno area for the last five to six years? The quick answer is no, but according to Kelly Redmond, regional climatologist at the Atmospheric Sciences Division of the Desert Research Institute, it puts us well on our way.
“This winter won’t end the drought altogether, but it does provide relief,” says Redmond. “It helps to reset the system.”
For those on the valley floor who endured the late, gargantuan snows that immobilized the area and crushed carports, the idea that drought is still a factor may seem exasperating, and in fact this year’s Sierra snowpack is clearly record-breaking. Following a spell of dry years, this winter’s precipitation was a sharp change and continues to bring moisture as spring storms come through the area.
But overestimating the impact of the snow can cause a decrease in water conservation and drought awareness, as happened in the early 1990s when California Gov. Pete Wilson prematurely declared an end to a drought that had lasted several years.
As Redmond points out, however, this area was far in the drought hole when this winter’s snows came. He is hoping there will be back-to-back wet years, which are much more effective in ending drought periods than separate years of moisture. In the last quarter century, this area has seen a pattern of wet and dry years blocked together. The last time the Sierra Nevada area experienced a wet spell, says Redmond, was in the 1990s, when climatologists saw six moist years.
“This is what we have seen for the past 25 to 30 years, regimes of wet and dry lasting several years.” said Redmond. “This is recent behavior for this area. We’ve had more fluctuation in the past 25 years than we have had in the history of this state.”
Redmond likes to point out, however, that when he says “the history of this state,” he means for as long as climatologists have been monitoring weather patterns, which currently stands at about 150 years for western Nevada. He did mention that in the 127 years of monitoring weather patterns in Los Angeles, this year proved to be the second wettest. Most weather patterns move from west to east. This year, Redmond says, the weather patterns moved from north to south.
“There was this division of weather that was conveniently drawn by the Interstate 80. Looking at the patterns above the 80 shows dry weather that continues to grow drier as you move north,” says Redmond. “Looking south of the 80 you see the opposite.” Redmond says snowpack measurements in the Lake Tahoe area grow noticeably larger as they move south.
Dan Greenlee is a hydrologist with the Natural Resources Conservation Service and the snow survey program manager. He physically measures the snowpack in different spots in the Sierra. Greenlee then converts those measurements into percentage of average water content to determine how much water, in comparison to average, is in the snow. Redmond says to envision a cylinder of snow and then think of how much water that cylinder contains.
“This concept is then expressed as the average water content,” says Redmond.
In Truckee, the average water content reached 126 percent of normal, compared to 84 percent last year. Measurements farther south increased by 20 percent or more. In the Walker basin, Greenlee reported, the average water content was 148 percent. This data supports Redmond’s hypothesis that the weather patterns produced more moisture as they moved south.
Greenlee says this is great news in what he calls “the long trip out of the current drought.” He also says that snowpack numbers like these will bring above-average stream flows this spring and summer.
“Somewhere around 80 percent of this area’s water comes from melting snow,” says Greenlee. “The snow on the hills is nature’s own widespread reservoir system.”
While this reservoir system appears to have provided the area with an unusual amount of greenery where the snow melts, DRI earth sciences Associate Professor Jay Arnone says the greenery on Reno’s hillsides is due more to the rainfall in the basin than the snowpack.
“As the snow melts and flows into various areas of the basin, we are going to see an increase in vegetation, but for now it is the rainfall that is causing the plants to grow,” says Arnone. He is looking farther down the road, however: Although the precipitation is good for the drought, it may not be good news for the fire season. Heavy moisture fosters the growth of groundcover plants that, when hot weather comes, dry out and cause fires to spread rapidly.
“Our biggest worry is that this is creating fuel for fires. So we need to be wary of fire dangers,” warns Arnone.
Water sports enthusiasts aren’t as worried. Instead, there is a feeling of anticipation. Chris Phipps with Chris-Raft whitewater rafting club is hoping this snowpack will produce an epic year for rafters and kayakers.
“It all depends on the late dumps of snow and how fast it gets warm,” says Phipps.
He says that on undammed rivers like the Carson, a favorite of many local rafters and kayakers, there needs to be late snow and then a sudden increase in temperatures. These create what Phipps calls “a bubble” of water flow.
“Otherwise, all you have is a trickle,” says Phipps. Dam-controlled rivers like the Truckee can’t rely solely on the snowpack from this year. Phipps says water flow will be controlled by a few different factors. Rafting companies who work the Truckee will have to wait for the word from the officials who control the dams. Those officials and the flows they create effectively determine just how good the rafting season will be.
“Since we have been in a drought, the reservoirs are low. Dam-controlled rivers may need another good year of snowfall to get the flow they want,” says Phipps. “It’s kind of like a savings account that way.”
Climatologist Kelly Redmond agrees with that analogy. “We’re going to have to see a few more wet winters to beat this drought.”