On July 17, millions of Americans faced hazardous weather conditions as wildfire smoke blanketed the East Coast, catastrophic flooding hit Texas, and 68 large blazes burned across 15 states. According to the National Weather Service and the National Interagency Fire Center (NIFC), these simultaneous extremes forced residents in multiple regions to stay indoors due to dangerous air quality and rising floodwaters.
Wildfire Activity and Air Quality Alerts
Firefighters are currently battling 68 large fires nationwide, an increase of nearly two dozen from the previous day. The National Interagency Fire Center reports that 17 new blazes erupted in the Pacific Northwest following lightning strikes. To combat these fires, the NIFC has deployed more than 17,400 personnel, 140 helicopters, and four military C-130 air tanker crews.
Nationwide, nearly 3.72 million acres have burned this year, which is over 1 million acres more than the tally for the same period last year. The NIFC attributes these conditions to drought and record-low snowpack in the Mountain West, which pushed fuel levels to a state of dryness typically not seen until mid-August.
Did You Know? Over 100 million Americans—nearly one-third of the U.S. population—were under some level of National Weather Service air quality alert, with instructions ranging from avoiding outdoor exercise to staying inside.
Smoke from Canadian wildfires turned skies orange-brown from Minneapolis to Washington, D.C. In Chicago, air quality was ranked as the second-worst in the world on Friday by IQAir. Local officials closed Lake Michigan beaches and parks, impacting the 4% of citywide households without air conditioning, according to the Civic Data Atlas. The National Weather Service activated community cooling centers as heat index values reached up to 97 F.
Texas Hill Country Flash Flooding
Texas Governor Greg Abbott confirmed two deaths following three days of catastrophic flash flooding in the Hill Country. The victims include a 65-year-old man swept away in an RV near Comfort and a 74-year-old man who drove into floodwaters in Uvalde County. The National Weather Service reported that some areas received more than 27 inches of rain since Tuesday.
Governor Abbott warned that rivers will continue to rise even as rains ease. This disaster occurs two weeks after the anniversary of a previous July flood on the Guadalupe River that killed at least 135 people in towns that are flooding again.
Expert Insight: The convergence of these disasters illustrates the danger of “compound events.” When smoke, fire, and flood occur simultaneously, the systemic strain on public health and emergency resources is significantly higher than when these events occur in isolation.
Climate Mechanisms and Jet Stream Resonance
University of Pennsylvania climatologist Michael Mann attributes these persistent extremes to “resonance,” a phenomenon where large waves in the jet stream become amplified and trapped. Mann stated his research indicates human-driven climate change has tripled these stalled jet stream events since the 1950s.
Jonathan Overpeck, dean of the University of Michigan’s School for Environment and Sustainability, explained that a warmer atmosphere drives both extremes. It pulls moisture from soil more aggressively, drying out Canada’s landscape, while simultaneously holding more water vapor to produce the intense rainfall seen in Texas.
Jesse Berman, a professor at the University of Minnesota School of Public Health, noted that these compound events can make impacts far worse than individual disasters.
Future Weather Outlook
The National Weather Service forecasts that rains in Texas may begin easing on Friday, though hot and dry weather is expected in the coming week. Major rivers in Texas are likely to crest over the weekend.
In the East, a heat dome over the Carolinas has been funneling smoke from Canada and Minnesota into populous corridors. Forecasted rain for the weekend could potentially clear the air.
Frequently Asked Questions
How many acres have burned in the U.S. so far this year?
Nearly 3.72 million acres have burned nationwide, outpacing last year’s mid-July total by more than 1 million acres.
Why is the air quality so poor in the Eastern U.S.?
Smoke from wildfires in Canada is being funneled by a heat dome parked over the Carolinas and northwesterly winds into the Midwest, Northeast, and Mid-Atlantic.
What caused the recent spike in wildfires in the Pacific Northwest?
According to the National Interagency Fire Center, a run of lightning strikes triggered some 17 new blazes in the region.
How does your local community prepare for compound weather extremes?
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