Examining and Forecasting the North American Monsoon's Impact on Fire Activity in the Southwestern United States

The Southwest Monsoon is an annual climate system phenomenon occurring over western Mexico and the southwestern U.S. from early July through mid-September exhibiting substantial interannual variability in terms of the onset date, strength and duration. The bulk of monsoon impact (i.e., moisture and lightning) occurs over Arizona and New Mexico, but the monsoon can also have influence over much of the West by pushing moisture and thunderstorms northward as far as the Canadian border. We defined the Southwest Monsoon's impact by fire activity for the core monsoon area of Arizona and New Mexico. We examined fire activity by Predictive Service Area (PSA) over the entire Southwest region under the influence of different monsoonal patterns including onset and monsoonal moisture surges and breaks. To improve prediction we examined teleconnections including the influence of the Madden-Julian Oscillation and the El Nino Southern Oscillation (ENSO), and known monsoonal surge and break impetuses such as easterly waves, transient upper level troughs (TUTTs), tropical storms, and rossby wave breaking (RWB). By examining these features, we will identify monsoonal patterns that significantly increase or decrease fire activity and better understand the impact of the Southwest Monsoon on fire business across the Southwest. A better understanding and improved forecasting of the identified monsoonal patterns will provide meteorologists and fire managers with better decision support tools.