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Recent Conditions
Published May 26, 2011

Southwest Snowpack

 (updated 5/23/11)
Data Source(s): National Water and Climate Center, Western Regional Climate Center

Snowpack is nonexistent in the Arizona basins (Figure 8). Snowpack remains at or below average in most of the basins in New Mexico with the exception of several northern basins. River basins in states to the north of Arizona and New Mexico that supply most of the water in the Colorado River and Rio Grande are experiencing above-average to near-average snow water equivalent (SWE). For example, SNOTEL sites in the Upper Colorado River Basin were at 202 percent of average as of May 19. SWE in the headwaters of the Upper Rio Grande measured 98 percent of average, and SWE in the Animas River Basin was about 144 percent of average. Accumulated winter precipitation in these three basins is 132, 99, and 105 percent of average, respectively. While precipitation has been above average in many places in Colorado and Utah since the water year began on October 1, precipitation has been below average at many SNOTEL monitoring stations located in Arizona and New Mexico as a result of the moderate to strong La Niña event.

Notes:

Snowpack telemetry (SNOTEL) sites are automated stations that measure snowpack depth, temperature, precipitation, soil moisture content, and soil saturation. A parameter called snow water content (SWC) or snow water equivalent (SWE) is calculated from this information. SWC refers to the depth of water that would result by melting the snowpack at the SNOTEL site and is important in estimating runoff and streamflow. It depends mainly on the density of the snow. Given two snow samples of the same depth, heavy, wet snow will yield a greater SWC than light, powdery snow.

This figure shows the SWC for selected river basins, based on SNOTEL sites in or near the basins, compared to the 1971–2000 average values. The number of SNOTEL sites varies by basin. Basins with more than one site are represented as an average of the sites. Individual sites do not always report data due to lack of snow or instrument error. CLIMAS generates this figure using daily SWC measurements made by the Natural Resource Conservation Service.
 

Southwest Snowpack

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