Front Range Air Quality Forecast & Colorado Smoke Outlook September 28

The Colorado Department of Public Health and Environment has issued an ACTION DAY ALERT at 4PM on Sunday, September 27, 2020 for the Front Range Urban Corridor from Douglas County north to Larimer and Weld counties, including the Denver-Boulder area, Fort Collins and Greeley.

Decreased activity at local wildfires has resulted in much improved air quality for most of the Front Range region. However, parts of central and western Larimer and Boulder Counties could still see periods of brief to heavy smoke through Monday afternoon due to their proximity to the Mullen and Cameron Peak wildfires.

This Particulates Action Day Alert will remain in effect until at least 4 p.m. Monday, September 28, 2020.

For statewide conditions, forecasts and advisories, visit:
www.colorado.gov/airquality/colorado_summary.aspx

At 10AM (MST), Monday, 9/28/2020 the highest AQI value was 33 for Ozone which indicates Good air quality.

The Colorado Department of Public Health and Environment and the Regional Air Quality Council's Summer 2020 Ozone Action Day Alert Program has concluded. The winter High Pollution Advisory Program begins on November 1. Air Quality Action Days or advisories for ozone for other pollutants, however, will be issued as needed at any time during the year and reported on this web page.

The Air Pollution Control Division's Winter 2020/2021 High Pollution Advisory Program will begin November 1. Thank you for your interest in and support for efforts to improve air quality for the citizens of the Denver- metro area.

Front Range Air Quality Forecast & Colorado Smoke Outlook

FRONT RANGE AIR QUALITY FORECAST:
Monday, September 28, 2020, 8:35 AM MDT

Ozone concentrations are expected to be in the Good category on Monday.

Fine Particulate Matter concentrations are expected to be in the Good to Moderate range on Monday for most areas. Decreased activity at local wildfires has resulted in much improved air quality for most of the Front Range region. However, parts of central and western Larimer County could see periods of moderate to heavy smoke through Monday afternoon, due to their proximity to the Mullen and Cameron Peak wildfires. In these areas people with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion on Monday. Elsewhere throughout the Front Range, Good to Moderate concentrations of fine particulates are expected, and unusually sensitive people should consider reducing prolonged or heavy exertion on Monday.

Carbon Monoxide concentrations are expected to be in the Good category on Monday.

Nitrogen Dioxide concentrations are expected to be in the Good category on Monday.

Visibility on Monday is expected to be Good to Moderate.

COLORADO SMOKE OUTLOOK:
Monday, September 28, 2020, 8:20 AM MDT

The 124,026 acre Cameron Peak wildfire is located in western Larimer County, approximately 15 miles southwest of Red Feather Lakes. Winds near the fire on Monday will be out of the northwest, transporting smoke to areas to the southeast of the fires location. Cooler temperatures and increased relative humidity have decreased fire activity and smoke production on Monday morning. However, a warming and drying trend is expected to allow a gradual increase in fire behavior, resulting in increased smoke production. Smoke impacts are expected to remain in areas in the immediate vicinity of the fire and in rural portions of Larimer County on Monday. Overnight Monday night, winds are expected to be light, and smoke will begin to settle in low lying terrain in areas immediately below the fire. This may bring periods of moderate smoke to areas in the Poudre River drainage in the Poudre Canyon, and the Laramie River drainage near the Wyoming border.

The 77,950 acre Mullen wildfire is located in western south-central Wyoming, approximately 38 miles west of Laramie, WY. Winds near the fire on Monday will be out of the northwest, transporting smoke to areas to the southeast of the fires location and into northern Colorado. Cooler temperatures and increased relative humidity have decreased fire activity and smoke production on Monday morning. However, a warming and drying trend is expected to allow a gradual increase in fire behavior, resulting in increased smoke production. Smoke impacts on Monday and Monday night are expected to remain in areas in the immediate vicinity of the fire in areas north of the Colorado border.

The 12,850 acre Williams Fork wildfire is located in southern Grand County, approximately 7 miles southwest of Fraser. Winds near the fire on Monday will be out of the west or northwest. This will transport smoke to areas to the east or southeast of the fires location. Overnight Monday night, winds are expected to be light, and smoke will begin to settle in low lying terrain in areas immediately below the fire. This may bring periods of moderate smoke to areas in the Williams Fork drainage near Parshall.

The 7,897 acre Middle Fork wildfire is located in Routt County, approximately 8 miles northeast of Steamboat Springs. Winds near the fire on Monday will be out of the west or northwest. This will transport smoke to areas to the east or southeast of the fires location. Overnight Monday night, winds are expected to be light, and smoke will begin to settle in low lying terrain in areas immediately below the fire. This may bring periods of moderate smoke to areas in the Mad Creek drainage.

What if there is a wildfire or smoke in your area?
The focus of the Colorado Smoke Outlook is on large fires (e.g., greater than 100 acres in size). Nevertheless, smoke from smaller fires, prescribed fires, and/or smoke from new fires not yet known to
CDPHE air quality meteorologists may cause locally heavy smoke. If there is smoke in your neighborhood, see the public health recommendations below.

Public health recommendations for areas affected by smoke:
If smoke is thick or becomes thick in your neighborhood you may want to remain indoors. This is especially true for those with heart disease, respiratory illnesses, the very young, and the elderly. Consider limiting outdoor activity when moderate to heavy smoke is present. Consider relocating temporarily if smoke is present indoors and is making you ill. IF VISIBILITY IS LESS THAN 5 MILES IN SMOKE IN YOUR NEIGHBORHOOD, SMOKE HAS REACHED LEVELS THAT ARE UNHEALTHY.

WHAT IS AN ACTION DAY?: An Action Day for fine particulate matter, carbon monoxide, ozone or other pollutants indicates that either current air quality is unhealthy or conditions are expected to worsen later in the day or on the next day. Action Days for air pollutants generally indicate that air quality will be in either the Unhealthy or Unhealthy-for-Sensitive-Groups categories according to the Air Quality Index. Action Days always convey overarching public health recommendations, and, according to season, trigger a variety of mandatory and voluntary pollution prevention measures. For example, during the summer open burning is prohibited when an Action Day for ozone and/or fine particulates is in effect. During the winter, residential burning restrictions are in effect when an Action Day for Visibility is in effect.

For a detailed description of both the AIR QUALITY INDEX and the VISIBILITY STANDARD INDEX please visit www.colorado.gov/airquality/brochure.aspx

COLORADO OPEN BURN FORECAST: For those with permits for open burning, that is the burning of waste materials or vegetation outside, check the following webpage to find out if open burning is allowed today. Keep in mind that open burning is prohibited when an Action Day is in effect:
www.colorado.gov/airquality/burn_forecast.aspx

FOR CURRENT FRONT RANGE ACTION DAYS/ADVISORIES:
www.colorado.gov/airquality/advisory.aspx

FOR CURRENT AIR QUALITY CONDITIONS STATEWIDE:
www.colorado.gov/airquality/air_quality.aspx

SOCIAL MEDIA:
www.facebook.com/cdphe.apcd
twitter.com/cdpheapcd

AIR QUALITY NOTIFICATIONS:
www.colorado.gov/airquality/request_alerts.aspx (CDPHE automated e-mail alerts)
www.enviroflash.info/signup.cfm (CDPHE forecasts via automated e-mails from the EPA)