Southwest Climate Outlook December 2013

Date issued

Precipitation: Precipitation across Arizona has been above average since November 19. More than 3 inches of rain and snow fell during a cut-off low system in late November in parts of the Mogollon Rim area. Elsewhere in the state, more than 1.75 inches have accumulated, mostly from the mid-November storm. The system that drenched Arizona, however, only clipped the northwest corner of New Mexico. Less than 75 percent of average precipitation has fallen in the southern half of New Mexico since November 19.

Temperature: Temperatures since November 19 have been generally below average in both Arizona and New Mexico, largely as a result of below-average maximum temperatures. Minimum temperatures, on the other hand, have been above average. The largest temperature anomalies have occurred in higher elevation areas.

Drought: Drought conditions remained virtually unchanged in the last 30 days in New Mexico; if present, drought conditions often persist this time of year because precipitation is scant. Arizona, however, saw slight improvements due to widespread rain in late November. Currently, moderate or more severe drought covers about 77 and 54 percent of New Mexico and Arizona, respectively. Drought was more intense and widespread in both states this time last year.

Snowpack: Snowpack in the headwaters of the Rio Grande in Colorado was about 116 percent of average as of December 17. In the Upper Colorado River Basin, average snowpack conditions in Utah were generally more than 200 percent of average, while watersheds in Colorado contained between 100 and 125 percent of average. Snowpack in the central Arizona highlands was also above average.

Water Supply: Reservoir storage in Arizona slightly decreased in November; combined storage in Lakes Mead and Powell dropped by about 56,000 acre-feet and the reservoirs are about 45 percent full. Storage slightly increased in New Mexico, with most gains occurring in Elephant Butte, which added about 44,000 acre-feet. Water storage in the state is only about 22 percent of average.

ENSO: Sea surface temperatures in the tropical Pacific Ocean remain near average, or ENSO-neutral, and these conditions are expected to persist through the winter.

Precipitation Forecasts: The NOAA-Climate Prediction Center is calling for elevated chances of below-average precipitation through the winter, reflecting both dynamical and statistical models. ENSO-neutral conditions, however, makes precipitation outlooks less certain.

Temperature Forecasts: The NOAA-Climate Prediction Center forecasts above-average temperatures for the December–February period. These forecasts are based in part on seasonal warming trends.

Published by the Climate Assessment for the Southwest (CLIMAS), with support from University of Arizona Cooperative Extension, the Arizona State Climate Office, and the New Mexico State Climate office.

Disclaimer. This packet contains official and non-official forecasts, as well as other information. While we make every effort to verify this information, please understand that we do not warrant the accuracy of any of these materials. The user assumes the entire risk related to the use of this data. CLIMAS, UA Cooperative Extension, and the State Climate Office at Arizona State University (ASU) disclaim any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will CLIMAS, UA Cooperative Extension, and the State Climate Office at ASU or The University of Arizona be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data.