An air stagnation advisory has been issued for the Portland-Vancouver metro area. The stagnant air will last through at least Saturday, according to the National Weather Service.
The stagnation is likely to bring with it limits on burning stoves and fireplaces, and could affect people with asthma and other breathing conditions as the air becomes increasingly foul.
According to the weather service, strong high pressure aloft will develop beginning this afternoon, trapping air in the valleys in the lowest 2,000 feet of the atmosphere.
The high pressure will persist until it is broken up by surface winds or a significant rainstorm, neither of which is in the short-term forecast.
Light showers are currently forecast for Friday, but not enough to mix the stagnant air with fresh.
