As strong winds blow smoke east from California and Oregon, Montana, the clouds of hazel hung over New York City and Pennsylvania.
The nation's largest wildfire, Oregon Bootleg Fire, reached 616 square miles (1.595 square kilometers), which is just half the area of Rhode Island. Both sides of California's Sierra Nevada, Washington State and other parts of the West were also affected by fires.
The East Coast smoke was reminiscent last fall when the smoke from large wildfires in Oregon caused a lot of smoke to rise, which not only clogged the sky but also negatively affected the air quality thousands of miles away. As the smoke blows east, Seattle and Portland have been mostly spared this year.
Residents of New Jersey, Pennsylvania, and other areas with asthma or heart disease were advised to stay indoors. Through Thursday, air quality alerts were in effect for certain parts of the region.
"We are seeing lots of fires producing tremendous amounts of smoke and... by time that smoke reaches the eastern part of the country, where it's usually thinnerned, there's just too much smoke in the atmosphere because of all these fires that it still thickens out," David Lawrence, a meteorologist at the National Weather Service. This phenomenon has been observed over the past two years.
Oregon's fire has decimated the southern region of the state, which is sparsely populated. It has expanded by as much as 4 miles (6 km) per day. This expansion has been fueled by gusting winds and dry weather that has turned undergrowth and trees into a tinderbox.
For 10 consecutive days, fire crews had to flee from the flames as fireballs jumped from treetops to treetops, trees exploded, embers flew ahead of the fire to light new fires, and in some cases the inferno's heat created its own weather with shifting winds and dry lightning. Monstrous clouds filled with smoke and ash can be seen for over 100 miles (161 km) in the sky, rising up to 6 miles (10km).
Oregon authorities said Tuesday's lower temperatures and winds allowed fire crews to strengthen their lines. They expect to make further progress Wednesday. It was close to an area of active fire on its southeastern flank, which raised hopes that it wouldn't spread as far.
About one-third of the blaze is contained. It is currently being fought by over 2,200 people. It was just a few hundred yards away from becoming Oregon's third largest wildfire in modern times.
At least 2,000 homes were evacuated during the fire, and another 5,000 are at risk. At least 70 homes have been destroyed and over 100 outbuildings damaged, but no one has been reported to have died. The area has been ravaged by thick smoke from residents and wildlife who have had to deal with extreme heat and drought for months.
Wildfires are more difficult to combat due to extreme dryness and recent heat waves linked to climate change. The West has become warmer and dryer over the past 30 years due to climate change. Wildfires will be more common and more destructive in the future.