JULY 2013
Vol 12 Issue 7

Drought: Monsoon rains helped improved drought conditions in a few areas in the Southwest, but the majority of Arizona and New Mexico continued to experience at least severe drought.   

Temperature: June was exceptionally hot in Arizona and New Mexico, but the onset of the monsoon in early July helped suppress high temperatures in southern regions of both states.

Precipitation: While monsoon rainfall has been copious in some areas, it has not been enough to compensate for deficits accumulated during the winter; most of the Southwest has experienced less than 70 percent of average precipitation since October 1.

ENSO: ENSO-neutral conditions are present in the Pacific Ocean and are expected to remain through the winter.

Forecasts: Temperatures are expected to be above average in coming months, while precipitation forecasts for the monsoon call for increased chances for wetter-than-average conditions in the southern Arizona and New Mexico border region.  

Summary Tweet:  Monsoon brings some drought relief to SW but NM still drought epicenter in US. Water supply very low. More SW Climate http://bit.ly/15gqIa0  (click to retweet)
Snapshot
The monsoon began around July 1 in southern regions of Arizona and New Mexico and has been active in parts of the Southwest. Above-average rain in the last month will likely improve short-term drought conditions and will be reflected in coming U.S. Drought Monitor Updates. Currently, however, due to precipitation deficits that have accumulated over the past year, most of the Southwest is classified with severe drought. New Mexico continues to be the epicenter of drought in the West with about 86 percent of the state experiencing extreme or exceptional drought. New Mexico has been experiencing some level of extreme or exceptional drought since March 2011. The dry conditions in recent years have caused reservoir storages to decline across both states. The 2013 water year inflow into Lake Powell is projected to be 41 percent of average; inflow for the 2012 water year was only 45 percent of average. In New Mexico, storage on the Rio Grande is at its lowest level since the early 1970s and irrigation allotments in the Elephant Butte Irrigation District and the El Paso Water Improvement District 1 have already stopped. This is causing farmers and urban centers to pump more groundwater and drill more wells. Monsoon rains-which have slightly increased chances for being better than average in coming months-will help lower water demand for some sectors, but will likely do little to improve overall water supply. The upcoming winter rain and snow will be crucial for reservoirs, as it was in 2011 when copious winter snows caused streamflows to be 145 percent of average and boosted the low reservoir storage in lakes Mead and Powell. Forecasts for winter precipitation, however, are uncertain in part because an ENSO-neutral event is likely-precipitation during ENSO-neutral winters does not substantially favor dry or wet conditions.