Heavy smoke continues for eastern Colorado. Keeping a close eye on the Western Slope.

Unfortunately we will see little to no change in smoke conditions across eastern Colorado on Wednesday.  Smoke continues to blanket the eastern half of the state which will continue to pose health concerns.  Those with heart and/or lung disease, older adults, and children will be most impacted by the poor air quality.  With that in mind, the health advisory for the eastern plains will be extended through at least 9am Thursday.  Although the entire plains are being impacted from the Wyoming to the New Mexico state lines, the further north you are, the worse the air quality is.  So take extra care if you are located in Fort Morgan, Akron, Julesburg, or any of the surrounding areas.  Our wildfire smoke and health webpage can give you tips and resources to help protect your health.

Hazy skies over Holyoke Municipal Airport Wednesday morning.  Image courtesy of the Federal Aviation Administration

The air quality is even more troublesome as you move west towards the Interstate 25 corridor.  The mixture of wildfire smoke with typical urban pollution is producing not only bad particle pollution, but also helping to enhance ozone.  This mixture of pollution will impact not only Denver, but also Ft. Collins, Boulder, Colorado Springs and Pueblo.  Because of this, we highly suggest for residents in these urban areas (along with the adjacent foothills to the west of I-25) that suffer from heart/lung disease, older adults, and children to avoid any prolonged or heavy exertion throughout the day today and limit time outdoors.  Even those that are considered healthy should slow it down today, and while outside take extra breaks to protect your health.

A Colorado map showing advisories by county.  Counties in purple are expecting elevated levels of both fine particulates (PM2.5) and ozone.

While all of this is going on across the eastern half of Colorado, the western half of the state is also seeing elevated levels of wildfire smoke -- but those levels are roughly 50-75% of those in eastern Colorado.  So currently there are no active advisories west of the Continental Divide.  However, we are monitoring the situation very closely as there is some smoke high up in the atmosphere over western Colorado that could mix down to the earth's surface during the late morning and afternoon hours.  If we start seeing a substantial increase in surface smoke concentrations, we will issue advisories.  It should be noted that there has been high ozone in the Grand Valley the past few days which is partially the result of wildfire smoke, so folks in the Grand Junction area should remain alert today and perhaps limit outdoor time Wednesday afternoon and evening.  Anyone can receive our air quality email alerts by signing up at our website.

So after three days of smoke, everyone is asking -- "When will this end?!?!".  Unfortunately it won't be today, but we do think we should see some gradual improvement Thursday and particularly heading into Friday.  The reason?  The upper level transport winds from the fires is finally getting cut off.  Note the upper level winds in the below graphics for today (left) vs. tomorrow (right).  Notice that the northerly wind flow coming from the Canadian fires today (left image) will push eastward onto the plains states tomorrow (right image).  With no fresh influx of wildfire smoke, the atmosphere will have an opportunity to (gradually) clean out.  We are also pleased to see that it appears the Canadian wildfires will receive at least some rainfall over the next few days.

The possible wild card?  If we see some new wildfire starts directly west of Colorado over the next 24 hours (central or southern California, Nevada, or Utah), we could see more smoke moving in by the weekend.  Fingers crossed that doesn't happen, but stay tuned!