Ozone is forecast in the Moderate AQI category over the next several days. In general, relatively light winds and sunny skies will favor formation of local ozone. The good news however, is that low pressure over the West will prevent any high pressure from developing, so ozone levels should remain capped in the mid to upper Moderate AQI range.

Then by Saturday into Sunday, a strong low-pressure wave is forecast to dive into the Southwest, resulting in breezy conditions on Saturday, and much winder conditions on Sunday. Daytime temperatures should also cool down by a few degrees on Sunday. During this time, ozone levels are forecast to decrease because of the greater atmospheric dispersion. However, PM₁₀ (dust) levels are forecast to increase, given the potential for dust, particularly on Sunday. Moderate PM₁₀ levels are currently forecast for Sunday.

Lastly, weekdays will likely continue to see Moderate PM₁₀ levels because of local activity in industrial areas south/southwest of Phoenix. Elsewhere around the Valley should see lower PM₁₀ levels, though.

Check back tomorrow morning for the next update!

- M. Graves
ADEQ Meteorologist