Oregon wildfire creates its own weather as fires across Northwest burn

An imposing column of gray cloud shoots into the sky from the Durkee fire — a wildfire that is around 244,000 acres burning in eastern Oregon.

That cloud is called a pyrocumulus cloud — or fire cloud. It's a weather phenomenon that forms similarly to a storm cloud, but is fueled by flames.

Bootleg Fire Incident Command via AP

"We have convection that's developing so that we have these very intense sources of heat, and then you have the winds coming from it that are mixing up the air and mixing the atmosphere and bringing that heat up through the column of the atmosphere," said David Bishop, a meteorologist from the National Weather Service in Portland, Oregon.

Bishop describes it as a convection oven. Heat and smoke from the wildfire create an updraft, which then hits cooler air in the atmosphere, creating a cloud.

This is similar to how a thunderstorm cloud is made, but the intensity of the heat and the fact that it is stationary make it different.

"That fire is just there. It's churning, it's keeping going," Bishop said. "So you're throwing more fuel up into the system so it can kind of develop on its own and propagate a lot further than a typical cumulonimbus cloud."

If the cloud is big enough, it can become its own weather system, creating wind, rain, and lightning.

The dry atmosphere that eastern Oregon is experiencing creates conditions conducive to wildfires.

"You have lightning that can easily pop out miles and miles downrange of the fire itself, to then again propagate that," said Bishop.

The Durkee fire near the Oregon-Idaho border has gotten so big that it's closed a section of Interstate 84. Crews from 22 states are battling the fire, and homeowners have been urged to evacuate.

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According to the U.S. Forest Service, there are 14 large wildfires burning in the Pacific Northwest. Parts of the region haven't seen significant rain in weeks, prompting the Forest Service to operate at the highest level of wildfire response possible.

The Forest Service Northwest posted a statement by regional assistant fire director Ed Hiatt saying, "This is shaping up to be another monster fire year in the Pacific Northwest and it's just mid-July."

"It's still going to be another couple of tricky days," said Bishop about the forecast.

With temperatures above average in the eastern part of Oregon, firefighters in the Northwest continue to have their work cut out for them.