Home » March 2012 Southwest Climate Outlook
Published March 21, 2012
Photo source: Bob Maddox

Storms have been few and far between in the Southwest this winter, leaving most of the region drier than average. A storm beginning on March 18, however, delivered much needed moisture to Tucson, where this photo was taken, and many other parts of Arizona. The event also brought several spurts of grauple, or soft hail. Photo source: Bob Maddox

March 2012 Climate Summary

Drought: Drought conditions continue to expand and intensify across Arizona, while severe drought continues to grip much of New Mexico.

Temperature: Several storms in February resulted in slightly below-average temperatures in Arizona and western New Mexico. The storms dodged eastern New Mexico, causing warmer-than-average temperatures there.

Precipitation: Precipitation in most of Arizona and New Mexico has been less than 75 percent of average in the past month.

ENSO: The current La Niña event is running out of steam and is expected to end by late April. ENSO-neutral conditions are forecast to hold sway through the spring and summer seasons.

Climate Forecasts: Warming trends in recent decades are driving forecasts for above-average spring and summer temperatures in the Southwest. Precipitation forecasts for these periods, however, are less definitive—monsoon season forecasts have historically been about as accurate as a coin flip.

The Bottom Line: Below-average rain and snow is almost guaranteed for many parts of the Southwest this winter in large part because of La Niña's influence. Despite a recent winter storm that brought much needed moisture to the Southwest around March 18, snowpacks and precipitation across most of the region are mostly below average. Similar to last year, January and February were dry, and rain and snow tallied less than 50 percent of average in these months in many parts of the Southwest. As a result, drought has expanded and intensified, most notably in Arizona. The scant precipitation is also driving forecasts that call for a 40 percent chance that spring flows in the Verde, Salt, and Gila rivers will be less than 60 percent of average, while the Rio Grande likely will be less than 90 percent of average. The Upper Colorado River Basin, which received historically high snowpacks during last winter’s La Niña event, also likely will experience well below-average streamflows this spring and summer. While the La Niña event is expected to end in April, spring storms in the Southwest—most notably in Arizona—are often few and far between, presenting few opportunities to overcome shortfalls in precipitation before the monsoon begins.

Comprehensive report on climate change in the Southwest open to public comment

The most comprehensive assessment on climate changes, impacts, and adaption strategies for the Southwest will be ready for public review on March 28. In the report, “Assessment of Climate Change in the Southwest United States: A Technical Report Prepared for the U.S. National Climate Assessment,” 100 experts focused exclusively on the links between climate, environment, and people in the Southwest, including Arizona and New Mexico. In this region, climate changes will continue to affect water supply, agriculture, energy production, vast stretches of coastline, an international border, and more. The report will make critical scientific contributions that help communities create more sustainable and environmentally sound plans for the future.

This report conforms to the Global Change Research Act of 1990, a federal mandate to synthesize climate-related information every four years. The editors and authors seek public comments on the report’s content and evidence used to support assessments. The open review will be held online beginning at 12 p.m. (PDT) Wednesday, March 28, and ending at 11:59 p.m. (PDT) Wednesday, April 11.

Learn more at http://swcarr.arizona.edu.