A summer like weather pattern will influence the area late this week. Expect effective dispersion of pollutants through Weds. Thursday-Sat a warm ridge of high pressure will trap some pollutants and allow for some elevated PM 2.5 levels in the Seattle area and elevated Ozone in the cascade foot hills S-SE of SEA-TAC metro areas. AQI will be good Thursday in most areas and briefly in the Moderate Category on Friday in the areas described above. AQI will return to GOOD on Saturday.