Dust Risk-Based Forecast | Maricopa County


Stagnation: Stagnation expected through the day

Wind: Mostly light winds


Stagnation: Morning and evening stagnation

Wind: Southwest winds 5-15 mph during the afternoon


Stagnation: Morning and evening stagnation

Wind: West-southwesterly winds 10-25 mph during the afternoon


Stagnation: Morning and evening stagnation

Wind: Northwesterly winds 5-10 mph


Stagnation: No stagnation expected

Wind: Northeasterly winds 10-25 mph

Forecast Discussion:

The major forecast update to pass along today is undercutting PM10 (dust) potential. We are certainly in a stagnant weather regime, but the buffer provided by recent and widespread rain on dust sources appears to be holding. That is good news for sure.

Fine particulates (PM2.5) constitute the only pollutant likely to maintain lower Moderate AQIs. A typical source for PM2.5 is soot from wood burning. Monitors in central and southern Phoenix see the highest impacts as pollution emissions generated from all over the Valley drain down to lower elevations of the metropolitan during the morning and overnight hours.

As for the weekend, there is a low pressure wave coming. Its inland trajectory over the Great Basin territory, while also not having a decent subtropical moisture connection, likely leads to a dry storm passage this time around for the Phoenix area. A few degree cool down and afternoon breezes on Sunday afternoon are the highlights.

- J. Malloy
ADEQ Meteorologist