El Niño Tracker - May 2016
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.
El Niño conditions continued for a 15th straight month, but the peak intensity has long since passed and the event is moving toward ENSO-neutral status. Forecast discussions focused on the decline of atmospheric and oceanic anomalies that characterize an El Niño event, many of which are trending towards—or have nearly reached—ENSO-neutral status. Seasonal ENSO outlooks and forecasts have coalesced around the likely transition to La Niña conditions in fall or winter 2016. The spring predictability barrier—a time during seasonal transition that introduces a high degree of uncertainty into seasonal forecast models—makes identifying the exact timing of this transition difficult, but most models and forecasts center on the general framing of “Not if, but when?” regarding La Niña in 2016.
On May 10, the Australian Bureau of Meteorology maintained its outlook at La Niña Watch status, noting that El Niño conditions had weakened to borderline neutral status and that there was a 50 percent probability of a La Niña event developing in 2016. On May 12, the Japan Meteorological Agency identified a decaying El Niño event that is expected to weaken to neutral conditions by late spring followed by a developing La Niña by summer 2016. On May 12, the NOAA-Climate Prediction Center (CPC) extended its El Niño Advisory and its La Niña Watch. The CPC identified current atmospheric anomalies as reflecting an ongoing but declining El Niño event, while oceanic anomalies were much more indicative of ENSO-neutral status. The CPC forecast an end to El Niño by early summer (i.e., a return to neutral conditions), with a 75 percent probability of a transition to La Niña in fall or winter 2016. On May 19, the International Research Institute for Climate and Society (IRI) and CPC forecasts described a rapidly declining El Niño event, with La Niña conditions more than likely developing by late summer (Fig. 3). The North American multi-model ensemble shows the current decline from strong to moderate El Niño status over the past few months, as well as the possibility of a relatively rapid swing to weak to moderate La Niña conditions by summer (Fig. 4).