Home » January 2013 Southwest Climate Outlook
Published January 23, 2013

January Climate Summary

Drought: Nearly all of Arizona and New Mexico are experiencing moderate drought or a more severe drought category.

Temperature: Most regions in Arizona and New Mexico experienced temperatures 4 to 8 degrees F below average in the last 30 days as a result of incursions of cold Arctic air.

Precipitation: Most of Arizona and New Mexico experienced less than 50 percent of average precipitation between mid-December and mid-January.

ENSO: Sea surface temperatures are expected to remain characteristic of ENSO-neutral conditions into the spring.

Climate Forecasts: February–April forecasts call for above-average temperatures and below-average precipitation.

The Bottome Line: The winter has been dry thus far. Precipitation across Arizona and New Mexico has generally measured less than 50 percent of average in the last 30 days and since the water year began on October 1. The water contained in snowpacks, or snow-water equivalent (SWE), is also below average across the Southwest, most notably in the upper Rio Grande headwaters and Upper Colorado River Basin where SWE is mostly less than 70 percent of average. Consequently, drought is still widespread and intense in the Southwest. Moderate drought or a more severe drought category covers nearly all of Arizona and New Mexico, with about 9 and 32 percent of Arizona and New Mexico, respectively, experiencing extreme drought. These conditions are not expected to change in coming months, according to the seasonal drought forecast. They may also deteriorate. There is some indication that the February–March period will deliver below-average rain and snow. This in part reflects the historical tendency for the West to experience below-average precipitation when ENSO-neutral conditions occur during the negative phase of the Pacific Decadal Oscillation, which is the current situation. ENSO-neutral conditions also leave room for more variable weather for the western U.S., which makes seasonal forecasting for Arizona and New Mexico more difficult. Nonetheless, if another dry winter does emerge, water stored in many of the region’s reservoirs will continue to decline, posing serious water supply challenges for those reservoirs teetering on the brink of emptiness. This includes San Carlos reservoir in Arizona, currently less than 1 percent full, and Elephant Butte Reservoir in New Mexico, which is currently only 7 percent full and provides irrigation water to New Mexico’s most productive agricultural region.

News Flash: Adapting to Expected Colorado River Shortfalls

A new, two-year study by the U.S. Bureau of Reclamation quantifies expected shortfalls caused by over-allocated Colorado River water and  assesses how to mitigate and adapt to these deficits.

Results of the study include a 9 percent decrease in streamflow measured at Lees Ferry over the next 50 years, taking into account climate changes. This decline is accompanied by increases in water demand, which is projected to range between 18.1 and 20.4 million acre-feet (maf) by 2060; consumptive use in the last 10 years has averaged 15.3 maf. The net result is that the Colorado River may experience an annual deficit of about 3.2 maf by 2060.

The ways in which the region adapts to and minimizes the deficit will be critical, and the study assessed more than 150 proposals to resolve the imbalance. These strategies included increasing water supply with reuse and desalinization and reducing demand through conservation and efficiency improvements. While the confluence of population growth and climate change in an arid region inevitably challenges water management, the report highlights that diligent planning and diverse strategies can reduce vulnerability to shortages while meeting increasing water demands.

To read more about the report, visit: http://www.usbr.gov/lc/region/programs/crbstudy/finalreport/index.html