KING

SEATTLE – A smog alert is in effect for Snohomish, King, Pierce and Kitsap counties until Wednesday night.

The Puget Sound Clean Air Agency says hot air is moving into the Puget Sound region from the south, bringing a temperature inversion along with it that will trap air pollution and impact air quality over the next several days.

The agency says air quality could be unhealthy Wednesday for sensitive groups in some areas.

KING 5 meteorologist Chris Warren said to expect temperatures in the mid to upper 80s both Tuesday and Wednesday, with a chance for 90-degree weather in inland areas. On Wednesday it will start to cool near the coast. Central Puget Sound areas will cool down on Thursday.

"When we have sinking air associated with high pressure, it's going to increase the chance for pollutants to be trapped at the surface," Warren said. "You need winds or rain to settle out the pollutants. Wind pushes it out of here or mixes it up, so you don't have all the sugar at the bottom of your coffee."

A spokesperson for the National Weather Service said winds will be light Tuesday and Wednesday, at speeds below 10 miles per hour.

"When you have light winds like next couple days, air doesn't move, it sticks in one place," said Art Gaebel. "Since we don't have that mixing of air, that's the reason we have elevated levels of smog."

Gaebel said there are usually a handful of days with this situation during the summer months.

The Puget Sound Clean Air Agency says people with asthma or heart disease should limit outdoor activities in the hot, hazy weather.

Residents are asked to do the following to help alleviate the air problem.

- Drive your most fuel-efficient car and combine errands into one trip.

- Skip gasoline-powered yard work and gas-fueled recreation.

- Carpool or ride the bus to work, events and outings. 

- Gas up your car in the cooler evening hours.