Yesterday's daily ozone was in the Upper Good AQI range, and today is forecasted to just reach the Moderate AQI category due to some higher values already early this morning. Wednesday is when more cloud cover arrives as more moisture enters while a trough builds to our west. This cloud cover will help ozone not build as easily compared to the start of this week, and more daily values in the Good AQI category are forecasted. Friday is when rainfall arrives, and this is expected to continue dropping the daily AQI through the Good AQI category into the weekend.

PM10 levels will have increases due to local activity, with higher increases found in the morning. As of right now, daily PM10 levels will be on the line of staying in the upper Good category or getting to the low Moderate AQI range. Again, this will be dependent on local activity in the mornings until Friday. Friday is when rain chances return, and this is when hourly PM10 values could rise as stronger gusts come. This will be monitored as we get closer as there are still differences on timing estimates. More steady rain is expected to move in later Saturday, and this will limit PM10 values as soils will be wet.

PM2.5 is forecasted to be in the low Moderate AQI range the next few days. This variability will come from morning increases from local activity along with cooler nights that lead to more wood burning and particulates staying near the surface. Rainfall arrives on Friday and could bring increases during the day, but the larger factor would be from the wood burning activities as temperatures cool after the rain.

- A. Hermansen
ADEQ Meteorologist