monsoon

Heavy snowpack in the Rocky Mountains reduces the intensity of the ensuing monsoon in the Southwest U.S. A new study presented by scientists at the American Geophysical Union fall meeting found that heavy snowpack cools the air by both reflecting more sunlight and keeping the soil wetter.

According to the newest Southwest Climate Outlook from CLIMAS, October temperatures were cooler than average in northern Arizona and New Mexico, while southeastern New Mexico and southern Arizona experienced above-average temperatures.

The monsoon is nearing its end, but the Southwest is still entrenched in dry conditions, with a large portion of the region—including all of Texas—in extreme to exceptional drought.

NOAA and the National Climatic Data Center recently released the State of the Climate overview for August and the entire summer, and the verdict is in: this was the second warmest summer on record for the U.S. It was also dry, with precipitation averaging 1.0 inch below the long-term average.

The monsoon rains have yet to really drench Arizona and New Mexico, leaving much of the region as drought-ridden as it was before the onset of the seasonal rains, according to the most recent Southwest Climate Outlook from CLIMAS.

The ridge of high pressure that controls the location of monsoon storms has remained east of its typical position over the Four Corners region this season, leaving eastern New Mexico dry, according to the August edition of the Southwest Monsoon Tracker.

Exceptional drought conditions continue across New Mexico, as rain has been sparse there since the beginning of monsoon season, according to the most recent Southwest Climate Outlook from the Climate Assessment for the Southwest.

The monsoon rains arrived on time in southern Arizona this year, according to the July 2011 edition of the Southwest Monsoon Tracker from the Climate Assessment for the Southwest.  However, the onset still has not reached southern New Mexico.

Researchers at the University of Arizona were awarded a $3 million grant from the National Science Foundation to study the ecology of the North American Monsoon. The five-year project will investigate how the monsoon affects the growth and spread of invasive grasses, and how tree-rings record the history of the monsoon, according to UA News.