The smoky haze blanketing the Chilkat Valley last week was the result of forest fires burning 3,500 miles away in Siberia.
The phenomenon occurred because two weather elements came together at the right moment—upper-level wind direction and a high-pressure system in Haines, according to National Oceanic and Atmospheric Administration (NOAA) meteorologist Caleb Cravens.
The smoke traveled to Haines via the jet stream, wind located 30,000-50,000 feet above the earth’s surface.
“Upper-level winds are the strongest winds, and so high up, there’s nothing up there blocking the smoke. They just take it, and it can travel far,” Cravens said.
The smoke arrived in the Chilkat Valley while the region was under a high-pressure system, last week’s string of sunny days, Cravens said. Instead of dispersing as it normally would, the smoke was trapped in the lower atmosphere, remaining in the region until a low-pressure system moved in over the weekend and the jet stream shifted so Haines was no longer downwind from the fires.
This isn’t the first time smoke from far away places has been visible to the naked eye in Haines. Last summer, smoke from fires burning in interior Alaska made its way to the Chilkat Valley under similar weather conditions, Cravens said.
He said last week’s smoke was not enough to be an air quality concern, but it was enough to make for “good sunsets,” as the dust particles in the air reflect and scatter sunlight, making visible a wider range of colors.