Issued for portions of central and western Colorado
Issued at 9 a.m. MDT, Tuesday, August 18, 2020
Issued by the Colorado Department of Public Health and Environment
Affected Area: Mesa, Delta, Montrose, Eagle, Pitkin, Lake, Gunnison, San Miguel, Ouray and central and eastern Garfield counties. Locations include, but are not limited to Fruita, Grand Junction, Palisade, De Beque, Delta, Montrose, Eagle, Avon, Vail, Aspen, Leadville, Crested Butte, Gunnison, Telluride, Lake City, Parachute, Rifle, Glenwood Springs, and Carbondale.
Advisory in Effect: 9:00 AM MDT, Tuesday, August 18, 2020 to 9:00 AM MDT, Wednesday, August 189, 2020.
Public Health Recommendations: 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.
Outlook: Areas of moderate to heavy smoke have been observed Tuesday morning across portions of central and western Colorado due to the Pine Gulch and Grizzly Creek wildfires. Smoke will gradually diminish Tuesday morning as atmospheric mixing increases, with the slowest improvement occurring in valley locations. By Tuesday afternoon the wind at the fires will initially be out of a westerly direction, but will shift clockwise to the north by late Tuesday afternoon. This could bring periods of moderate to heavy smoke for areas to the east, southeast and south of both wildfires. By late Tuesday evening smoke will begin to drain into lower lying areas surrounding both fires. This will bring longer duration, heavy smoke through early Wednesday morning to several drainages near the Pine Gulch wildfire including into the De Beque, Grand Junction, and Fruita areas. Meanwhile, heavy overnight smoke from the Grizzly Creek wildfire will continue to impact locations along Interstate 70 in central and eastern Garfield County.
Where to watch for information
State advisories are on the State Air Quality Health Advisory page. Garfield County air quality monitors continue to provide real-time and 24-hour air quality information.
There will be periods of moderate to heavy smoke, as indicated by the PurpleAir sensors along the I-70 corridor.
Low-cost sensors, such as PurpleAir, can be used as an indicator of elevated levels of particulates in the air and help by adding data coverage in areas where there are not permanent regulatory monitors.
Public Health advises setting the default to a “one day average” rather than “10-minute average” because being exposed to moderate to heavy smoke for a short term period may not have the same health impacts as being exposed for a full 24-hours.
It is important to understand that these low-cost sensors are not considered accurate enough to be used in regulatory action. These sensors are not a reference method nor approved by EPA for compliance with federal air quality standards.