An air stagnation advisory was issued for much of Eastern Washington on Tuesday as a mass of stable high pressure moved ashore across the Pacific Northwest.

The system was expected to bring cooler temperatures and little wind, allowing air pollution levels to rise without adequate ventilation in the atmosphere. Stagnant conditions have been forecast through Saturday morning.

According to the Spokane County Air Pollution Control Authority, air pollution levels had reached the moderate range on Tuesday, but were not bad enough to trigger mandatory restrictions on outdoor burning or wood stove use in the Spokane area smoke control zone. SCAPCA was asking residents to voluntarily refrain from wood burning.

The National Weather Service in Spokane reported that persons with respiratory illness should follow their physician’s advice for coping with high levels of air pollution.