Smoke to linger in Seattle area, degrading air quality

SEATTLE — Smoke from wildfires in the Cascade Mountains is likely to hang around the Puget Sound region through the weekend, possibly pushing the air quality down to levels considered unhealthy for sensitive groups — or even worse — in parts of King and Snohomish counties.

A high-pressure system has parked itself over the Seattle area, said National Weather Service meteorologist Samantha Borth, causing airflow to stagnate. That should change early next week as some weak breezes arrive from the northwest, providing a bit of ventilation.

The bad news is that another high-pressure system is likely to flow in again later in the week, meaning the haze and degraded air quality could return.

In broad terms, Washington saw a relatively mild year for wildfire smoke. But above-average temperatures and below-average rainfall have meant the risk of polluted skies has stubbornly hung on into autumn. Both the Bolt Creek and Goat Rocks fires continue to burn and will likely continue to do so until the first significant dump of rain.

While slightly lower temperatures and shorter days have helped firefighters, the Bolt Creek Fire still saw growth of about 100 acres late in the week, according to the incident management team overseeing the response to the fire.

The first week of October was Seattle’s warmest on record, averaging 63.5 degrees and toppling the previous record set in 1987, according to the National Weather Service. At 77 degrees, Friday was the warmest Oct. 7 on record, said Borth, exceeding the previous mark of 75 degrees set in 1951. The record for Oct. 8 is 80 degrees, also set in 1951.

The trend will likely persist into next week, said Borth, with temperatures hanging 10 to 15 degrees above what’s considered normal for this time of year. Tuesday will be the only day that resembles an October day in the Northwest.

Despite the toasty start to fall, meteorologists are still forecasting another La Niña year for the Northwest, meaning a good helping of cold and wet.