Dust Risk-Based Forecast | Pinal County


Stagnation: Light stagnation

Wind: Light winds becoming west 5-12 mph


Stagnation: Moderate stagnation

Wind: Light becoming west 4-9 mph


Stagnation: Moderate stagnation

Wind: Light winds


Stagnation: Moderate stagnation

Wind: Light winds becoming south late 5-15 mph


Stagnation: No stagnation

Wind: South 10-25 mph, gusts 30-35 mph, diminishing late

Forecast Discussion:

An upper level low pressure system will form off of the California coast and move southward this weekend. This low pressure system will eventually stall and retrograde (i.e. move in the opposite direction, west) off the Baja California coast this weekend due to a ridge of high pressure to its north. Eventually that high pressure will weaken and be replaced with a more vigorous upper level low pressure system. The first low pressure system located to our southwest will weaken and move east early next week. The path that this first low pressure system takes will be rather important as it may provide some rain for the local area on Tuesday. The amount and spatial extent of that rain is very important from an air quality perspective as the second low pressure system will bring strong winds for Wednesday of next week. If the area doesn't receive sufficient rains on Tuesday then blowing dust becomes a concern for next Wednesday. In regards to the dust risk forecasts for the next five days, have moderate dust risks for this weekend as the early morning winds at Hidden Valley should be from a less than ideal (i.e. easterly) direction and so the early morning PM10 spikes are expected to be minimized. Weak high pressure will be in brief control of the area on Monday and so expect the Hidden Valley monitor to approach the PM10 health standard and so have a high dust risk. Early morning weather conditions on Tuesday bring another chance for favorable light easterly winds at Hidden Valley and so more PM10 spikes are possible and so have a high dust risk forecast for Tuesday. Have a high dust risk forecast for Wednesday due to the possibility for strong winds that generate areas of blowing dust. Check back on Monday for an updated dust risk forecast.

- S.DiBiase
Pinal County Air Quality Meteorologist