3 DAYS-IN-A-ROW OZONE HIGH POLLUTION ADVISORIES ALERTS: July 19, July 20, and July 21

Ozone GPA: High Pollution Advisory (HPA)

Notifies the public that the level of an air pollutant is forecast to exceed the federal health standard.

HEALTH IMPACTS: People most vulnerable to the impacts of air pollution include children, older adults, adults exercising outdoors, people with heart or lung disease, and those suffering from asthma and bronchitis.

Exposure can increase the number and severity of asthma attacks, cause or aggravate bronchitis or other lung disease, and reduce the body’s ability to fight infection.

Symptoms may include itchy eyes, nose and throat, wheezing, coughing, shortness of breath, chest pain and upper respiratory issues.

Ground-level ozone forms when two types of pollutants — volatile organic compounds (VOCs) and nitrogen oxides (NOx) — react in sunlight.

These pollutants come primarily from automobiles, but also from other sources, including industries, power plants and products, such as solvents and paints. Generally, the highest levels of ozone occur in the afternoon.

FIND THE FORECAST

Air Quality Hourly Forecast | View > 

Forecast Discussion: Ozone ramped up quite high yesterday and easily reached the Unhealthy for Sensitive Groups AQI category at several monitors in the Phoenix area.

We are still under a monsoon weather pattern, bringing daily showers and thunderstorms to Arizona. However, here in Phoenix we're expecting any showers we do get the next couple days to be later in the evening. This will likely give enough time for ozone to continue to reach the Unhealthy for Sensitive Groups AQI category today and tomorrow. Therefore, we do have Ozone High Pollution Advisories in effect for today (Tuesday) and tomorrow (Wednesday).

On Thursday, there is potential for earlier storm activity in the area, which may be enough to lower ozone into the Moderate AQI range. Then, on Friday and Saturday we are improving ozone a little further, again due to more storm activity in the area and slightly better ventilation. Of course, the weather can change quickly this time of year, so be sure to check back each day for any adjustments to the forecast.

Looking at particulates, we don't anticipate any significant issues. There is potential for gusty winds from thunderstorm outflows each evening, which could kick up a little dust. However, the surrounding area has received a decent amount of rain recently, which should be enough to prevent any major blowing dust. Therefore, we are forecasting PM₁₀ and PM_2.5 to remain in the Good AQI range through the forecast period.

- R. Nicoll
ADEQ Meteorologist

About ADEQ Under the Environmental Quality Act of 1986, the Arizona State Legislature established the Arizona Department of Environmental Quality in 1987 as the state agency for protecting and enhancing public health and the environment of Arizona. For more information, visit azdeq.gov.

 

FOR IMMEDIATE RELEASE High Pollution Advisory issued for Ozone effective July 21, 2021, in the Phoenix area

The Arizona Department of Environmental Quality (ADEQ) is issuing a High Pollution Advisory (HPA) for ozone effective July 21, 2021, in the Phoenix area. ADEQ recommends that people limit outdoor activity while the HPA is in effect, especially children and adults with respiratory problems. Ground-level ozone forms when two types of pollutants — volatile organic compounds (VOCs) and nitrogen oxides (NOx) — react in sunlight. These pollutants come primarily from automobiles, but also from other sources, including industries, power plants and products, such as solvents and paints. Generally, the highest levels of ozone occur in the afternoon.

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FOR IMMEDIATE RELEASE | High Pollution Advisory issued for ozone effective July 19 & 20, 2021, in the Phoenix area

The Arizona Department of Environmental Quality (ADEQ) is issuing a High Pollution Advisory (HPA) for ozone effective July 19 & 20, 2021, in the Phoenix area. ADEQ recommends that people limit outdoor activity while the HPA is in effect, especially children and adults with respiratory problems. Ground-level ozone forms when two types of pollutants — volatile organic compounds (VOCs) and nitrogen oxides (NOx) — react in sunlight. These pollutants come primarily from automobiles, but also from other sources, including industries, power plants and products, such as solvents and paints. Generally, the highest levels of ozone occur in the afternoon. Check the Hourly Air Quality Forecast on the Air Arizona Mobile App Apple iTunes > | Google Play > Health Impacts People most vulnerable to the impacts of air pollution include children, older adults, adults exercising outdoors, people with heart or lung disease, and those suffering from asthma and bronchitis. Exposure can increase the number and severity of asthma attacks, cause or aggravate bronchitis or other lung disease, and reduce the body’s ability to fight infection. Symptoms may include itchy eyes, nose and throat, wheezing, coughing, shortness of breath, chest pain and upper respiratory issues.

Air Quality Hourly Forecast | Phoenix

Updated On: 7/19/2021 - 8:55 AM

Click on each day to view forecast.

Monday Forecast:

Alert: Ozone High Pollution Advisory in effect for Monday

Ozone

101 AQI
Max 8-hr Avg: 71 ppb

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PM10

38 AQI
24-hr Avg: 41 µg/m³

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PM2.5

28 AQI
24-hr Avg: 6.7 µg/m³

Air Quality By Pollutant:

Pollutant

Monday
7/19/2021

Tuesday
7/20/2021

Wednesday
7/21/2021

Thursday
7/22/2021

Friday
7/23/2021

O3

101

105

97

93

84

PM10

38

40

43

39

38

PM2.5

28

31

33

29

29

O3 = Ozone, PM10 = Particles ≤ 10 microns, PM2.5 = Particles ≤ 2.5 microns 

Forecast Discussion:

On Saturday, ozone reached the Unhealthy for Sensitive Groups AQI category at several monitors in the Valley. However, yesterday barely reached the Moderate category due to all the cloud cover from showers and thunderstorms skirting by the area. Ozone forecasting this time of year can be tricky, as so much depends on the sporadic nature of thunderstorms and the cloud cover associated with them. There is some lingering cloud cover this morning, but that will likely burn off shortly. Sunny skies and light winds today will likely allow ozone levels to increase. Similar conditions are expected tomorrow as well, which will likely allow for elevated ozone levels again. As a result,Ozone High Pollution Advisories are in effect for today (Monday) and tomorrow (Tuesday). 

Later in the week, we are looking at the potential for more thunderstorms and lingering cloud cover that could prevent ozone levels from building up quite as much. Therefore, we are forecasting ozone to drop into the Moderate AQI category for Wednesday through Friday. The expected weather can change quickly this time of year, so we will adjust accordingly if we expect any changes. 

As for particulates, we are not expecting any significant dust. We could still see strong winds from thunderstorms in the evenings that could kick up a little dust. However, with pretty good rainfall amounts throughout the area, it is unlikely we will see any significant blowing dust. Therefore, we will be forecasting PM10 and PM2.5 to stay in theGood AQI range through the week. 

- R. Nicoll
ADEQ Meteorologist