Southwest Snowpack

Below-average precipitation across most of the region in the last month caused snowpacks to decrease in Arizona and New Mexico. In Arizona, the amount of water contained in snowpacks, or snow water equivalent (SWE), measured by snow telemetry (SNOTEL) stations was less than 50 percent of average in all but one river basin as of March 15 (Figure 8). The central Mogollon Rim and the Verde River Basin measured only 15 and 20 percent of average, respectively. The San Francisco Peaks had the highest SWE, at 81 percent of average—down 14 percent from one month before. A recent storm beginning on March 18 and not reflected in the SWE values reported here will help boost snowpacks in Arizona but likely will not push values above average in many places.

In New Mexico, seven of the 11 river basins reported in Figure 8 had well below-average snowpacks. The San Francisco and the Gila river basins, located in the southwest corner of the state, measured 50 percent of average. The Zuni/Bluewater River Basin in central New Mexico was the only basin with above-average SWE, measuring 121 percent of average. Northern areas benefited from a few storms in February, but high winds increased sublimation, especially at lower elevations. Sublimation is the transformation of snow to water vapor, which reduces snowpacks.

Colorado and Utah also have below-average SWE, with all but one basin reporting below-average snowpacks. Snowpacks may melt earlier than average this year, as the NOAA-Climate Prediction Center (CPC) forecasts above-average spring temperatures. There is still ample time for spring storms to blanket the mountains in snow, although forecasts call for equal chances for above-, below,- or near-average precipitation.