Southwest Climate Outlook April 2014

Date issued

Drought: Drought conditions remained unchanged in the last 30 days with the exception of southwest Arizona and central New Mexico, where drought intensified. Currently at least moderate drought covers about 89 and 97 percent of Arizona and New Mexico, respectively.

Precipitation: In the past 30 days, a small amount of rain fell only in parts of northern Arizona and New Mexico, leaving both states with below-average precipitation totals in the last month. Since January 1, less than 50 percent of average rain and snow has fallen in nearly all of the two states.

Temperature: Temperatures in the last 30 days were above average, continuing a pattern that has persisted all winter. Above-average temperatures were caused in part by fewer storms wafting into the region from colder, northern regions.

Snowpack: Snowpacks are typically low this time of year in Arizona and New Mexico. Nevertheless, snowpacks across both states are below average, much as they have been all winter. Snowpacks in the Upper Rio Grande Basin in Colorado are 72 percent of average. In parts of the Upper Colorado River Basin, however, snowpacks are mostly near or above average.

Water Supply: Total reservoir storage decreased by about 647,100 acre-feet in Arizona and increased by about 48,000 acre-feet in New Mexico in March. Storage stands at about 44.5 percent of capacity in Arizona and about 23.5 percent of capacity in New Mexico. Lake Mead fell by about 550,000 acre-feet.

ENSO: Probabilities that a El Niño event will develop in the summer or fall continue to increase. El Niño events affect winter atmospheric patterns more than summer for the Southwest and often deliver above-average precipitation to the region. The last El Niño event was in 2009.

Precipitation Forecasts: The NOAA-Climate Prediction Center is calling for slightly increased chances for above-average precipitation across the Four Corners region during the May–July period and equal chances elsewhere. May and June are typically the driest months of the year.

Temperature Forecasts: The NOAA-Climate Prediction Center forecasts high chances for above-average temperatures in the Southwest during the May–July period.

Streamflow Forecasts: The April-July streamflow forecasts for the Colorado River call for flows into Lake Powell to be around 110 percent of average, which was similar to forecasts made last month. In New Mexico, the March-July forecast for the Rio Grande at Otowi Bridge is around 32 percent of average, which is 6 percent less than the forecast made on March 1.

Fire Forecasts: Below-average precipitation and low snowpacks in Arizona and New Mexico contribute to above-average significant fire potential in the May–July period for most of the Southwest.

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.