Future regional increases in simultaneous large Western USA wildfires

We then applied these models to regional climate model simulations of the 21st century from the NA-CORDEX data archive. Key results. The results project increases in the number of simultaneous 1000+ acre (4+ km(2)) fires in every part of the Western USA at multiple return periods.

These increases are more pronounced at higher levels of simultaneity, especially in the Northern Rockies region, which shows dramatic increases in the recurrence of high return levels. Conclusions. In all regions, the models project a longer season of high simultaneity, with a slightly earlier start and notably later end.

These changes would negatively impact the effectiveness of fire response. Implications. Because firefighting decisions about resource distribution, pre-positioning, and suppression strategies consider simultaneity as a factor, these results underscore the importance of potential changes in simultaneity for fire management decision-making.