July 2016 SW Climate Outlook - Monsoon Tracker
Assistant Research Professor, Arizona Institutes for Resilience
Assistant Professor of Anthropology, School of Anthropology
Ben McMahan joined CLIMAS after completing a PhD in Sociocultural Anthropology at the University of Arizona. His dissertation research was on hurricanes and disaster on the U.S. Gulf Coast, where he focused on
- Human interactions in dynamic social and environmental contexts,
- Risk perception and landscape changes during and after disaster, and
- Social network and policy responses to governance issues related to the acute threats of disaster; as they layer onto long term environmental issues and landscape scale changes.
He was also a key contributor to UA Bureau of Applied Research in Anthropology (BARA) collaborative/trans-disciplinary research on the social, economic, and environmental impacts of the US Oil and Gas industry (2007-2011), and the aftermath of the Deepwater Horizon oil spill (2010-2013).
At CLIMAS, his research activities included tracing how climate information is incorporated into regional decision maker networks, leading CLIMAS team research on the risks and effects of climate extremes, and collaborative research on the effects of climate variability on phenology and temporality of native plants in the region. He was also responsible for working to develop collaborative research opportunities and outreach efforts at CLIMAS, and as part of ongoing assessment and science/strategic planning, he contributed to strategic planning used to prioritize future research and outreach directions. He also coordinated publication of the monthly Southwest Climate Outlook, produced the Southwest Climate Podcasts, and was the online editor for CLIMAS’ blog - Southwestern Oscillations.
The southwestern monsoon officially starts June 15 and ends September 30 – the dates the National Weather Service began using in 2008 to identify the window of typical activity for the region. The historical start date of monsoon activity (increased dew point, onset of precipitation events) varies across the region and is reflected in a generally westward migration over the season (Fig. 1). The monsoon ridge also shifts throughout the season, and the location of this ridge helps determine where storms and precipitation events will occur.
The Southwest saw a strong start to the monsoon in the second half of June, with a number of heavy rainfall events, particularly across southern Arizona. Most of July has been characterized by a monsoon “break” for the Southwest, with very few precipitation events other than in the southeastern corner of Arizona. Since the start of the monsoon, most of Arizona and New Mexico have recorded below-average precipitation (Figs. 2a-b), but this is early in the season and a wide range of precipitation totals and considerable spatial variability is to be expected at this point (Figs. 3a-b). The percent of days with rain highlights the irregular coverage of monsoon precipitation thus far, with much of the heavy precipitation activity clustered in southeastern Arizona and across much of New Mexico (Figs. 4a-b).