Southwest Climate Outlook May 2014

Date issued

Precipitation: An active jet stream has brought several moisture-starved storms into the Southwest in the last 30 days, delivering windy conditions but little rain. While dry conditions are normal during this time of year, most of the Southwest has received less than 50 percent of average precipitation since April 15.

Temperature: Temperatures in the last 30 days were mostly below average in Arizona and New Mexico except in southwest Arizona, where temperatures were above average. Below-average temperatures across the Southwest were caused in part by several moisture-starved storms wafting in from colder, northern regions.

Snowpack: Snowpacks have melted in nearly all of Arizona and New Mexico. In the Colorado portion of the Upper Colorado River Basin, several storms—the same ones that delivered windy conditions to the Southwest—boosted snowpacks; that area has also received above-average precipitation since January 1. On the other hand, below-average snowpacks are present in the Rio Grande headwaters; precipitation there has been mostly below average since January 1.

Water Supply: Total reservoir storage decreased by about 380,600 acre-feet in Arizona in April; Lake Mead fell by about 648,000 acre-feet. Storage stands at 44 percent of capacity in Arizona and is lower than it was one year ago. In New Mexico, storage increased by 50,300 acre-feet in April. Storage is at 24 percent of capacity and is greater than it was one year ago.

Drought: Drought conditions intensified in some regions of Arizona and New Mexico. Moderate drought expanded in southwest Arizona and severe drought expanded in central New Mexico. In northeastern New Mexico, extreme drought deteriorated into exceptional drought. Compared to one year ago, drought conditions are similar in Arizona and less intense in New Mexico.

ENSO: Sea surface temperatures and atmospheric conditions continue to indicate the likelihood that an El Niño event will form.There is greater than a 60 percent chance that an El Niño will develop during the summer.

Precipitation Forecasts: The NOAA-Climate Prediction Center (CPC) is calling for slightly increased chances for above-average precipitation across the Four Corners region during the June–August period. While many dynamical models simulate increased precipitation in the monsoon region, El Niño in the past has been associated with weaker early monsoon activity. These mixed signals cause greater uncertainty in the monsoon region.

Temperature Forecasts: The CPC forecasts high chances for above-average temperatures in the Southwest during the June–August period based on many different signals, including dynamical models and temperature trends.

Fire Forecasts: Above-normal fire potential for the May–June period is focused on central and southeast Arizona and southwest New Mexico west of the Continental Divide. This forecast is based on the presence of drought conditions, the availability of dry fine fuels, the heightened potential for warm and dry conditions, and lightning strikes.

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.