Your primary source of information for news from and about the University of Arizona.

June 29, 2023

UArizona monsoon and wildfire experts available

TUCSON, Ariz. – The North American monsoon, a seasonal shift in atmospheric circulation that brings moisture to a usually parched landscape, officially started on June 15. But the rain has yet to fall in Southern Arizona, and Tucson temperatures have been consistently in the triple digits for the past two weeks, fueling concern for wildfires in the region.

Climate models have predicted a late start to the rain and potentially a season that with slightly less than the 5.5-inch average rainfall.

University of Arizona climate scientist Michael Crimmins hopes rain is around the corner but said it is likely still a few weeks away.

The heat is a good sign, though, he said. Moisture that fuels monsoon rain usually hitches a ride up from the south – including the Pacific Ocean and Gulf of Mexico. Soaring temperatures are usually a signal that moisture can start making its way northward.

Until rain arrives, wildfire risk continues to climb. While heavy rain and snow over the winter and cooler-than-average May temperatures delayed fire season, recent triple-digit heat across Southern Arizona, combined with the lack of rainfall, puts the region at risk, said Molly Hunter, a UArizona fire ecologist. This is especially true as the greenery that flourished after the winter rain and snow continues to dry out.

Currently, six fires are burning about 17,000 acres in Arizona, according to the National Interagency Fire Center.

"There are a lot of ignitions right now, but not a lot of acreage burning, yet," Hunter said. "We're entering a critical period and can expect a lot of activity before the rain hits. Before the monsoon, we typically get a lot of lightning. It's dry, hot and very windy. That sets up critical fire conditions."

Several UArizona experts are available to answer monsoon and wildfire questions.

Monsoon experts

Michael Crimmins is a climate scientist in the Department of Environmental Science and a co-host of the Climate Assessment for the Southwest, or CLIMAS, podcast. He is also a co-director of the volunteer precipitation monitoring program and is the creator of MyRAINge Log, which allows ranchers and land managers to collect, manage and use precipitation observations to support management decisions.
(Available Thursday and Friday, then not again until the week of July 17)

Zackry Guido is an assistant research professor in the School of Natural Resources and the Environment and the Arizona Institute for Resilience, where he is also director of international programs. Guido is co-creator of the Southwest Monsoon Fantasy Forecasts game, now in its third year, which allows amateur forecasters to submit their monsoon predictions online and compete for prizes. He also studies how people adapt to and cope with environmental stressors, and the role of weather and climate information in decision making.

Theresa Crimmins directs the USA National Phenology Network and is an associate professor in the School of Natural Resources and the Environment. She can speak to the Buffelgrass Green-Up forecast map, which allows people to see when and where buffelgrass can be sprayed with herbicide while it's green and most vulnerable, usually after monsoon rain. Buffelgrass is an invasive plant that can fuel wildfires and harm desert species not adapted to large-scale intense fires.

Heidi Brown is an associate professor in the Department of Epidemiology and Biostatistics who studies health impacts of climate exposures. In particular, she studies how climate influences insects like mosquitos to spread diseases such as West Nile virus and dengue to humans. She has expertise in other climate-associated hazards, including heat-related illness and wildfire exposures. Through collaborations at the Centers for Disease Control and Prevention and in the United Kingdom, she is also working to develop a model to optimize trapping effectiveness for mosquitos.

Fire experts

Molly Hunter is an associate research professor in the School of Natural Resources and the Environment. She can speak about applied fire science, including the ecological effects of wildfires and effectiveness of different fire mitigation techniques.
(Available after July 10)

Donald Falk is a professor in the School of Natural Resources and the Environment. He studies fire history, fire ecology, tree-ring analysis, post-fire resilience and restoration ecology. Falk can speak about possible links between wildfires and climate change and how ecosystems recover from wildfires. He has worked extensively in the western U.S. and Mexico, reconstructing historic fire spatial and temporal patterns from tree rings.

# # #

Media contact:
Mikayla Mace Kelley
University Communications

The University of Arizona, a land-grant university with two independently accredited medical schools, is one of the nation's top 50 public universities, according to U.S. News & World Report. Established in 1885, the university is widely recognized as a student-centric university and has been designated as a Hispanic Serving Institution by the U.S. Department of Education. The university ranked in the top 20 in 2021 in research expenditures among all public universities, according to the National Science Foundation, and is a leading Research 1 institution with $824 million in annual research expenditures. The university advances the frontiers of interdisciplinary scholarship and entrepreneurial partnerships as a member of the Association of American Universities, the 71 leading public and private research universities in the U.S. and Canada. It benefits the state with an estimated economic impact of $4.1 billion annually.