 It starts at the northwest edge of the Des Moines metro area and extends diagonally across the state, lowering breathable air quality from Council Bluffs through Sioux City, Ames, Mason City, and Decorah. KMA on track weather, 30% chance of showers and thunderstorms late this afternoon. Sunny with highs in the mid-80s. Still a 30% chance of showers and thunderstorms tonight. Lows in the lower 60s. Mike Peterson, KMA News.