Unhealthy plume of smoke blankets Inland Northwest

Raging wildfires in Okanogan County sent a plume of smoke over the Spokane area Wednesday evening, while air quality at ground level deteriorated to the unhealthy range for people with health issues such as lung disease.

The cloud darkened the sky and turned the sun orange, bathing the city in an eerie and ominous orange-brown light.

Ron Miller, forecaster with the National Weather Service in Spokane, said fire weather conditions deteriorated severely Wednesday, allowing fires to grow and spread rapidly. Dangerous fire weather is expected to continue through Friday. A “red flag” fire weather warning is in effect until then.

The North Star fire in north-central Okanogan County was primarily responsible for Wednesday evening’s smoke cloud, which was clearly visible on satellite images as it drifted toward Spokane on higher-elevation winds, Miller said.

At the same time, smoke at ground level was coming from the Carpenter fire near Fruitland in Stevens County, he said.

Air quality in Spokane had improved to the moderate range during much of the day on Wednesday, but the Spokane Clean Air Agency’s monitors were showing worsening conditions throughout the evening.

Mark Rowe, the agency’s air quality technician, said the official “air quality index” is based on a 12-hour average, with more weight to the most recent readings. This agency’s forecast said the air quality could be rated unhealthy for all people today because of smoke and blowing dust.

Other locales in the Inland Northwest were seeing much worse air pollution from smoke, especially near the east slopes of the Cascades, according to AirNow, a website that tracks air quality around the country.

The most smoke-plagued areas were nearer to the fires, according to the AirNow map.

Miller said a thermal low-pressure area made it easier for fires to grow Wednesday by allowing more upward motion in the atmosphere.

The upward lift also led to variable winds.

Dangerous fire weather under a thermal low can be unpredictable since updrafts and downdrafts are not anticipated easily, Miller said. That is different than a situation like last Friday, when the danger from horizontal winds was readily apparent as well as being forecast in advance.

A red-flag warning for dangerous fire weather is in effect through Friday.

A cold front is expected to increase winds to 20 to 30 mph with gusts to 40 mph in some areas today and Friday. In Spokane, gusts may reach 25 mph out of the southwest today and then 30 mph from the west on Friday.

Fire zones northwest of Spokane are expected to see northwest winds.

Assistant Spokane Fire Chief Brian Schaeffer said fire departments within Spokane County will have additional resources on hand Thursday because of the expected hazardous conditions.

“We all need to make a sincere effort to take care of each other as we are facing several difficult days ahead,” Schaeffer wrote in an email to the full Fire Department staff. “The next 48 hours in the Spokane region is forecasted to have high winds and extremely hazardous Red Flag conditions. The anticipated conditions combined with fatigue and an overall lack of resources makes it extremely dangerous for the fire service in the Pacific Northwest. Maintain your situational awareness, regardless of your assignment and keep a critical eye on each other – supporting each other is critical to the mission’s success and the collective fire service brother-sisterhood.”