Thunderstorm activity over Arizona will be quite isolated today and Saturday before a gradual uptrend is anticipated next week. An Extreme Heat Warning (issued by the National Weather Service) is now in effect through Monday.

Peak 8 hour average ozone is anticipated to increase somewhat over the next few days rising from the upper Good range to the lower Moderate range.

Daily average PM10 values are anticipated to be in the Moderate range today aided by a brief period of blowing dust that occurred in the early morning hours plus local agricultural activities. With limited storm activity, anticipate the daily average to be in the upper Good range Saturday and Sunday. Of note, outflow winds originating from northern Sonora could potentially cause a brief spike in the overnight hours. By Monday and Tuesday, thunderstorm winds are anticipated to be more likely and thus there is higher potential for late afternoon and evening blowing dust and in turn, the projected 24 hour averages climb into the Moderate range.

Daily average PM2.5 is anticipated to be a bit better than PM10 and remain in the Good range. But, blowing dust episodes can cause short lived spikes in PM2.5.

- A. Jamison
ADEQ Meteorologist