Phoenix Forecast

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Air Quality Hourly Forecast | Phoenix

Click on each day to view forecast.

Thursday Forecast:


Ozone

45 AQI
Max 8-hr Avg: 49 ppb

PM10

77 AQI
24-hr Avg: 107 µg/m3

PM2.5

53 AQI
24-hr Avg: 13.2 µg/m3

Friday Forecast:


Ozone

42 AQI
Max 8-hr Avg: 45 ppb

PM10

87 AQI
24-hr Avg: 127 µg/m3

PM2.5

61 AQI
24-hr Avg: 16.9 µg/m3

Saturday Forecast:


Ozone

44 AQI
Max 8-hr Avg: 48 ppb

PM10

59 AQI
24-hr Avg: 72 µg/m3

PM2.5

54 AQI
24-hr Avg: 13.7 µg/m3

Sunday Forecast:


Ozone

43 AQI
Max 8-hr Avg: 46 ppb

PM10

53 AQI
24-hr Avg: 59 µg/m3

PM2.5

42 AQI
24-hr Avg: 10.0 µg/m3

Monday Forecast:


Ozone

45 AQI
Max 8-hr Avg: 49 ppb

PM10

61 AQI
24-hr Avg: 76 µg/m3

PM2.5

44 AQI
24-hr Avg: 10.5 µg/m3

Air Quality By Pollutant:

Pollutant
Thursday
11/14/2019
Friday
11/15/2019
Saturday
11/16/2019
Sunday
11/17/2019
Monday
11/18/2019
O3
45
42
44
43
45
PM10
77
87
59
53
61
PM2.5
53
61
54
42
44
Pollutant
THU
FRI
SAT
SUN
MON
O3
45
42
44
43
45
PM10
77
87
59
53
61
PM2.5
53
61
54
42
44
O3 = Ozone, PM10 = Particles ≤ 10 microns, PM2.5 = Particles ≤ 2.5 microns

Forecast Discussion:

A cool, crisp morning in the Valley of the Sun. Low temperatures have dipped below 60 degrees in the city, while winds are light for the lower deserts. That type of tranquil weather is going to be the norm for a while. As alluded to earlier this week, a buildup in particulates is anticipated under the light wind regime. Morning hourly readings in the downtown vicinity (e.g., West 43rd monitor) are climbing higher compared to days prior in response to stronger trapping inversions before sunrise.

Although highest concentrations are being found in the downtown area, everyone in the Valley contributes to the pollution levels. The geography of the landscape tends to drain toward the base of South Mountain, so even stirred dust or soot from wood burning happening in the west, north, and east portions of the Valley can follow the terrain and add to particulate concentrations in the heart of the Phoenix metropolitan. It is a big city spread over a large territory, but we are more interconnected than it may seem. This is something to keep in mind as the season is only going to get colder and winter inversions last longer with a lower sun angle.

Back to the present. Highest daily Air Quality Index values (AQIs) are forecasted for Friday. We got light winds again and a band of cloud cover to move overhead. There is abundant high altitude moisture spilling in from the East Pacific. Even high clouds can have an indirect impact on our air quality by preventing surface heating. Surface heating is good for inversion breakup and causing upslope winds that drive the daytime mountain-valley circulation. Weak sunlight and persistent inversions are a recipe for pollution accumulation. It will likely look hazy tomorrow for much of the day.

Clouds move on and it is back to sunshine by the weekend. A general improvement to air quality follows.


- J. Malloy
ADEQ Meteorologist


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Thursday: Yellow
Friday: Yellow

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