Phoenix Forecast

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Air Quality Hourly Forecast | Phoenix

Click on each day to view forecast.

Friday Forecast:

Notice: Blowing dust possible in the afternoon/evening

Ozone

58 AQI
Max 8-hr Avg: 57 ppb

PM10

65 AQI
24-hr Avg: 83 µg/m3

PM2.5

56 AQI
24-hr Avg: 14.7 µg/m3

Saturday Forecast:


Ozone

74 AQI
Max 8-hr Avg: 62 ppb

PM10

41 AQI
24-hr Avg: 44 µg/m3

PM2.5

43 AQI
24-hr Avg: 10.2 µg/m3

Sunday Forecast:


Ozone

58 AQI
Max 8-hr Avg: 57 ppb

PM10

35 AQI
24-hr Avg: 38 µg/m3

PM2.5

41 AQI
24-hr Avg: 9.8 µg/m3

Monday Forecast:


Ozone

71 AQI
Max 8-hr Avg: 61 ppb

PM10

53 AQI
24-hr Avg: 59 µg/m3

PM2.5

47 AQI
24-hr Avg: 11.2 µg/m3

Tuesday Forecast:


Ozone

84 AQI
Max 8-hr Avg: 65 ppb

PM10

55 AQI
24-hr Avg: 63 µg/m3

PM2.5

49 AQI
24-hr Avg: 11.7 µg/m3

Air Quality By Pollutant:

Pollutant
Friday
9/17/2021
Saturday
9/18/2021
Sunday
9/19/2021
Monday
9/20/2021
Tuesday
9/21/2021
O3
58
74
58
71
84
PM10
65
41
35
53
55
PM2.5
56
43
41
47
49
Pollutant
FRI
SAT
SUN
MON
TUE
O3
58
74
58
71
84
PM10
65
41
35
53
55
PM2.5
56
43
41
47
49
O3 = Ozone, PM10 = Particles ≤ 10 microns, PM2.5 = Particles ≤ 2.5 microns

Forecast Discussion:

Arizona's weather over the next few days will be dictated by a low pressure wave now sitting just off the coast of southern California. Increased moisture, cloud cover, and even small rain/thunderstorm chances will also be in store for the Valley.

Already this morning (Friday), decent cloud cover can be seen on satellite over southeastern Arizona and making its way into the Valley. These clouds will help to reduce local ozone production (ozone needs sunlight to form). Then later today, gusty thunderstorm winds from the south will be possible. These winds could result in brief blowing dust and may even trigger isolated thunderstorms. Any thunderstorm-related winds in the afternoon should also help to limit ozone.

Then by Saturday, cloud cover and additional thunderstorm chances will continue through the morning and into the afternoon. But what's most noteworthy is that high temperatures could finally fall below 100°F, which is about normal for this time of year anyways. Any cloud cover and/or thunderstorm winds will help to reduce ozone, on top of the better atmospheric dispersion provided by the low pressure wave itself.

Our brief open door for thunderstorms then looks to shut by Sunday. However, we won't lose our atmospheric dispersion, as another low pressure wave--this one traversing the Northwest U.S.--influences Arizona's atmosphere Sunday into Monday. Stronger atmospheric winds associated with this wave are expected to help limit ozone levels in Phoenix, despite light winds near the ground.

On Tuesday, ozone levels are forecast to trend upwards again as high pressure returns to the region.

In regards to particulate matter, PM10 (dust) could be elevated this evening because of thunderstorm-induced blowing dust. But other than that, weekdays should continue to see Moderate PM10 levels given regular morning activity in industrial areas south/southwest of the Phoenix metro area.

PM2.5 (smoke) will be highest in the morning hours each day. Whether or not PM2.5 is able to make it into the Moderate AQI category will largely depend on how high it is able to reach in the morning.

We should also note the possibility of wildfire smoke from California moving over central Arizona, though it should remain overhead.

- M. Graves
ADEQ Meteorologist


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