Wildfire Season Is Here

Over the past few months, the U.S. has been buffeted by a pandemic, protests over racist police violence, and two tropical storms. Add wildfires to the list as well, as the West prepares to start the week with tinderbox conditions.

An area from California to the Texas Panhandle is under a red flag warning on Monday. Relative humidity could plummet into the single digits, and you don’t need to be a fire scientist to know that’s not a good sign. With dry air and fuels, all it will take is an errant spark to start a fire. High temperatures and gusty winds are in turn expected to fan flames of already-burning fires and could spread new ones.

Arizona is home to the largest fire in the U.S. right now, according to data from the National Interagency Fire Center (NIFC). The Sawtooth Fire began last week in the Superstition Wilderness area to the east of Phoenix and has burned through nearly 25,000 acres. Though it’s mostly contained at this point, fires burning elsewhere in the state are out of control. That includes the Blue River Fire, which was up to 18,000 acres as of Sunday, and the Bighorn Fire near Tucson, which stood at 1,000 acres and was largely uncontained.

Those fires could have company on Monday. The main ingredient fueling the fire danger for the Southwest is a front moving across the West that has turned the weather warning map into a rainbow of weirdness, including everything from critical fire conditions to winter storm advisories.

That front is creating what’s called a trough in the jet stream. The river of air in the sky normally locks colder air to the north and warmer air to the south, but a trough allows cold air to come spilling farther south than normal, which is exactly what’s happening to start the week. Winter has returned to parts of the Northern Rockies, where snow fell on Monday and winter weather advisories are in place.

The same cold front is also passing through the Southwest, minus the moisture. So instead of cold, wet conditions, it’ll be colder, windy conditions followed by a blast of heat after the front passes. Low pressure over Colorado and high pressure over the Southwest will create a gradient for winds to gust up to 50 mph after the front passes through. And that’s how you end up with critical fire conditions across nearly 224,000 square miles.

This fire season has, mercifully, been less active than average so far. But that could change: The NIFC is forecasting above-normal fire activity throughout the summer. That includes more activity in the Southwest in June and July, the region’s peak wildfire season. The bullseye for blazes will shift to California and then the Pacific Northwest as the season progresses.

Climate change has increased the odds more destructive, larger fires, as well as lengthened fire season as a whole. The season now stretches 105 days longer, largely due to rising temperatures that melt snowpack sooner and can keep blazes burning later into the year. Humans have also moved into harm’s way, and decades of forest fire policy have left forests with more fuel to burn. We’ve seen the impact in the form of town-consuming fires and policy responses like California’s preemptive blackouts. The coronavirus is throwing yet another stressor on top of fire season, by both forcing people who evacuate into close contact and unleashing plumes of smoke that can agitate the respiratory system, potentially making people more vulnerable to respiratory illness like covid-19. If you were hoping from a break from calamity and heartbreak, it’s probably not coming anytime soon.