Advisories issued for several parts of eastern Colorado Wednesday

 Plenty of smoke to be found across eastern Colorado Wednesday morning.  An Action Day for Multiple Pollutants is already in effect for the northern Front Range region, including Denver, Boulder, Ft. Collins, Greeley, and surrounding areas due to the combination of wildfire smoke and ozone that is expected today.  Unfortunately three sizable wildfires (Alexander Mountain, Stone Canyon, and Quarry) are feeding additional smoke into the I-25 corridor.  Although there is smoke throughout the area, locally heavier smoke can be found in closer vicinity to those three wildfires.  Notice on the below image from the EPA's Fire and Smoke Map the higher levels of particle pollution (in oranges and reds) downwind of those three fires in Loveland, Longmont, and southwestern parts of the Denver metro area.  Gradual improvement with the smoke is anticipated by this afternoon in areas close to the fires as the atmosphere begins to heat up, but keep in mind that ozone will also be increasing this afternoon.  So today might be a good day to just move your plans indoors, if possible.  While outside, be sure to take plenty of extra breaks.

   

Meanwhile, this morning's cold front brought an influx of out-of-state smoke to the eastern plains.  Webcam images and monitoring data reveal moderate to heavy smoke across the northeastern corner of Colorado, so an Air Quality Health Advisory for Wildfire Smoke will be in effect through at least 9am Thursday.  We do anticipate some improvement with the air quality for the eastern plains on Thursday, so hopefully we will not need to extend the advisory beyond 9am.

Webcam image from Holyoke Municipal Airport looking southwest towards the eastern Colorado plains.  Image courtesy of the Federal Aviation Administration

Light, but possibly noticeable smoke can be found in other parts of the state as well.  Some smoke moved into northwestern Colorado overnight from Wyoming.  Fortunately, smoke levels are not terribly high and major public health impacts are not anticipated.  However, if you suffer from asthma or other respiratory ailments, you may want to take it easy today and limit exertion while outdoors in Steamboat Springs, Craig, and Rangely.

Smoke is also likely to have an influence on ozone today.  Ozone is already part of the current alert in the northern Front Range region, but elevated ozone is also possible further south in the Colorado Springs and Pueblo metropolitan areas. Therefore, we have issued an Air Quality Health Advisory for Ozone for those areas today as well.

Throughout this current smoke episode, we continue to advise those impacted to protect your health with plenty of resources available at our Wildfire smoke and health webpage.  You can also monitor the air quality in your area with the EPA's Fire and Smoke Map.

Current air quality advisories for Colorado

Smoke has arrived to northeastern Colorado

An air quality alert is already in place today along the I-25 urban corridor from Denver northward to Ft. Collins due to expected high levels of both ozone and particle pollution from wildfire smoke.  We are now considering raising the flag on an advisory for parts of the adjacent plains to the east as out-of-state wildfire smoke has rushed in with a cold front early this morning (as evidenced by the Akron webcam below).  More information soon to follow.

Webcam image from Akron courtesy of Viaero

 

Heavier smoke tonight for the northern Front Range

The Alexander Mountain and Stone Canyon wildfires have been raging today and produced enormous amounts of smoke.  Most of that smoke has lofted well into the atmosphere, but unfortunately that will change tonight.  Once the sun sets, atmospheric mixing will decrease significantly and smoke will no longer be able to rise into the atmosphere.  At that point, smoke acts like water and seeks its lowest point. In the current situation, two highly populated areas are directly below these two fires.  For the Alexander Mountain, it is Loveland.  For Stone Canyon, it is Lyons.  Both of these communities can expect smoke levels to increase significantly overnight.  Please shut your windows before going to bed tonight as being inside will offer you some measure of protection from the smoke.  

Keep in mind that we are also anticipating an influx of out-of-state wildfire smoke late tonight with a cool front moving in from the north.  So there is a good chance that the entire northern Front Range region from Ft. Collins to Denver could wake up to smoky skies and elevated particle pollution levels Wednesday morning.

New fire start near Lyons, 7/30/24

 In addition to existing air quality concerns, a new start adds to the expected impact on air quality due to smoke from the Stone Mountain wildfire near Lyons. 

Map of approximate location of Stone Mountain wildfire.

This new addition of smoke to the Front Range airshed will further increase the likelihood of significant air quality impacts for locations such as Lyons, Longmont, and nearby areas, as expressed in our earlier post. These conditions are expected to continue through Tuesday and Wednesday, at the very least. 

Stay tuned for additional updates.

Smoke on the Front Range coming from several sources this week

 While a lot of attention on smoke in northern Colorado is focused on the Alexander Mountain fire (and rightfully so), smoke transport from other fires in the western U.S. will also play a role in air quality conditions as the week progresses.

A weak cool front will move through the area on Tuesday night, and is expected to create surface winds out of the north on Wednesday. This will push smoke from the Alexander Mountain fire into areas further south of those that are already affected, and will also bring smoke from fires in upwind states into the mix. On Tuesday morning air quality impacts from the out-of-state fires are already seen across northern and western Wyoming (as well as other states), and with winds shifting to move things toward the south, we expect to see some of that smoke move into Colorado overnight Tuesday and into Wednesday morning.

Map of  smoke (fine particulates) impact on air quality in courtesy of PurpleAir.

By 9 am MDT (15 UTC) on Wednesday the HRRR-Smoke model shows smoke produced locally moving southward from Loveland, CO along the Front Range, reaching at least as far south as the Denver Metro area. Additionally, the smoke currently to our north will move into northern and central Colorado, with the highest concentrations hugging the eastern slope of the Rockies, worsening air quality conditions along the Front Range. This means that in addition to smoke being seen in Loveland and along Highway 34, increased particulate concentrations are expected in Fort Collins, Greeley, Longmont, Boulder, Denver, and surrounding areas.

The impact from out-of-state transport of smoke will also be seen in areas of northern/northwestern Colorado, and on the eastern plains. Though concentrations are expected to be a bit less than will be seen along the Front Range, light to moderate concentrations of smoke are expected across large areas of the state, with potential to affect many outdoor recreation areas and outdoor workers in these areas. We encourage everyone to remain aware and cautious in regard to heavy physical exertion, especially when outdoors, due to the heat and air quality that will affect Colorado in the coming days.

With these expectations in mind, along with temperatures in the mid-to-upper 90's and limited cloud cover, air quality concerns for health impacts due to exposure to both fine particulates (smoke) and ozone will be heightened this week. CDPHE/APCD will keep a close eye on conditions as all of this develops, however it is likely that the Ozone Action Day alert that is currently in effect for the northern Front Range region will be upgraded to an Action Day for Multiple Pollutants as particulate pollution spreads to wider areas.

Heavy smoke in southeastern Larimer County

 Unhealthy air quality can be found across the southeastern corner of Larimer County Tuesday morning due to smoke from the Alexander Mountain wildfire.  EPA's Fire and Smoke Map reveals that the city of Loveland is really getting hit hard with smoke this morning.  

Monitoring data in Loveland shows short-term levels of Unhealthy to Very Unhealthy air quality

We urge residents of Loveland and others in southeastern Larimer County to please take extra steps to protect your health this morning.  Please keep your windows closed and limit your time outdoors this morning, especially if you suffer from heart or lung disease, or are an older adult.  Keeping children inside this morning is also probably a wise idea.  If you still have some N-95 masks, they can be effective against wildfire smoke.  If you start to have health symptoms that lead you to believe that your indoor air quality has also become unhealthy, consider relocating to an area with better air quality if you have the ability to do so.  Of course, please see your health provider if your health symptoms continue to worsen.  You can find all this information along with additional resources at our wildfire smoke and health webpage.

The view from Northern Colorado Regional Airport looking west towards Loveland and the Alexander Mountain wildfire shows the extent of the smoke.  We issued a health advisory for southeastern Larimer County yesterday afternoon which expires at 9am this morning.  However we will be extending that advisory through at least 9am Wednesday with little sign that the fire will be easing up anytime soon.  

Webcam image from Northern Colorado Regional Airport courtesy of the Federal Aviation Administration

Although the advisory will run from 9am today to 9am tomorrow, that does not necessarily mean that the smoke is going to be heavy in southeastern Larimer County all day long.  As the atmosphere heats up, much of the smoke will lift up into the atmosphere which will improve air quality at the earth's surface.  Although the air will not be pristine this afternoon (ozone will likely be elevated), it will certainly be better than what it is this morning.  So if you do need to spend some time outdoors today, this afternoon and evening will be the better option for your health.  Residents in the area should remain updated on the latest information regarding the Alexander Mountain wildfire, including evacuation areas and shelters, at Inciweb's Alexander Mountain Fire webpage.

Alexander wildfire west of Loveland

 The Alexander wildfire is located just to west of Loveland and to the north of state highway 34.  This fire is already producing enormous amounts of smoke, so we have issued an Air Quality Health Advisory for southeastern parts of Larimer County.  Fortunately the bulk of the smoke should remain up in the atmosphere and not create any extended air quality problems through Monday evening, though we could certainly see some quick hits of surface smoke from the plume in Loveland, Timnath, Windsor and southern parts of the Ft. Collins area.  The smoke may get more troublesome and create bigger health impacts later tonight when the smoke begins to "lay down" and seek it's lowest point.  So we should be prepared for the potential for heavy smoke overnight tonight and into early tomorrow morning along State Highway 34 below the fire and eastward into the Loveland area.  We will continue to monitor this wildfire and provide updates as necessary, but if you do reside in the Loveland area you will likely want to keep your windows closed tonight and visit our wildfire smoke and health webpage for additional resources to protect your health.

Image of the Alexander Fire courtesy of the Arapaho Roosevelt National Forest

Heavier smoke possible mid-week for Colorado

Fortunately, it appears that throughout Colorado there is no heavy smoke to be found Monday morning.  Smoke has generally been light to moderate for most areas with heavier smoke remaining well to the northwest of Colorado.  The EPA's Fire and Smoke Map shows where the heavier smoke is currently located:  northern California, southeastern Oregon, southern Idaho, and northwestern Wyoming.  That smoke is mostly coming from the very large fires burning in northern California.  The light to moderate smoke Colorado is currently experiencing has its origins mainly from fires in southern California.  Those fires are large as well, but not producing as much smoke as the fires further north in California.

Heavy particle pollution from wildfire smoke, denoted in reds and oranges, located northwest of Colorado

Regardless, there will be some smoke in the air today which could cause discomfort to some.  This is especially true for the larger metropolitan area around Denver as the wildfire smoke will mix with the regular urban pollution.  If you suffer from asthma or COPD, you may want to slow it down a bit today.  Air quality will likely worsen Monday afternoon as particle pollution levels may begin to increase in combination with the soaring temperatures during the hottest part of the day.  The National Weather Service has issued Heat Advisories today for several locations along the Front Range, including Ft. Collins, Boulder, Denver, Colorado Springs and Canon City, so please do limit your outdoor time this afternoon if possible.

The big question this week:  Will Colorado receive some of that heavier smoke to the northwest?  If so, when?  There are indications that Colorado could tap into some of that heavier smoke by Wednesday.  A weak cool front (we hesitate to say cold front as the temperatures will only drop a few degrees) could move in as early as Tuesday night and may bring some surface air in from the north and northwest.  It's quite possible that air could contain some heavier wildfire smoke for Wednesday, so we will be monitoring conditions very closely over the next few days and provide updates here as the situation continues to evolve.

Jones Fire burning in Mesa County

The Jones Fire is burning in Mesa County approximately 15 miles southeast of Fruita. It is burning in the King's Canyon area of the Black Ridge Canyons Wilderness.

If you are upwind of this fire, you may notice haze in the sky. Satellite imagery shows smoke traveling as far as Glenwood Springs. Overnight, the smoke may become moderate to heavy in valleys and low-lying areas, as daytime mixing decreases. Fruita, Grand Junction, Rifle, and Glenwood Springs may see moderate to heavy smoke by Monday morning.

An Air Quality Health Advisory is in effect for Mesa and Garfield Counties until 9 am Monday morning.

A Red Flag Warning is in effect for Mesa County until 8 pm Sunday evening.

Satellite imagery shows a plume of smoke visible to the west of Grand Junction.

Twin Forks Fire burning in Jefferson County

The Twin Forks Fire is burning in Jefferson County along US-285 near Turkey Creek Road. This fire is less than 10 acres, and crews are on the scene.

While no major public health impacts are expected from this fire, locations near the fire may experience moderate smoke. Unusually sensitive people near the fire should consider reducing prolonged or heavy exertion.

The Jefferson County Sheriff's office is posting updates to X.

Smoke making a quick return to parts of Colorado

 The Park wildfire near Chico, California is receiving plenty of attention this weekend due to it's massive size, rapid spread, and significant damage it has caused.  However, the Park wildfire is not the fire that is going to send smoke into Colorado over the next few days.  The culprits will be fires that are further south in California, along with other parts of the desert southwest.  In the below visible satellite image, note the two large smoke plumes in southern California, along with some smaller plumes in Arizona and Utah.  These are the fires that Colorado will need to monitor in the short-term.  Information on these fires can be found at the InciWeb website.

Visible satellite image courtesy of Colorado State University's CIRA satellite webpage

Sadly, it looks like smoke from this complex of fires will be transported in the direction of Colorado through at least Tuesday.  In the below image showing upper level transport winds for Sunday afternoon, notice the blue shaded area from southern California through the desert southwest and into Colorado.  The wind barbs in this area show winds that are blowing from the southwest to the northeast.  So any smoke that is produced at the wildfires today is expected to head directly towards Colorado.

600 millibar wind model courtesy of Weathernerds.org

Will the entire state be impacted?  Possibly, but there is little doubt that over the next few days the smoke will be more noticeable across the northern half of Colorado.  For this afternoon, particle pollution (PM2.5) may start to increase in Julesburg, Greeley, Ft. Collins, Denver, Boulder, Rocky Mountain National Park and Steamboat Springs.  Smoke modelling is anticipating some of the biggest increases in PM2.5 today across the northwestern corner of Colorado, so a special heads up to those in Craig, Rangely, and those who may be planning to visit Dinosaur National Monument.  To make matters even more dicey, the National Weather Service office in Grand Junction has issued Red Flag Warnings for large parts of western Colorado today, so the threat for wildfires starting in-state is also a distinct possibility.

Improving air quality.......slowly

 The EPA's Fire and Smoke Map shows a lot less orange than it did at this time yesterday.  Wildfire smoke is comprised of fine particulates (PM2.5), and orange on the map corresponds to air quality that is considered "Unhealthy for Sensitive Groups".  So that is good news.  But there is still far too much yellow on the map to our liking, which is considered "Moderate" air quality.  This is especially true for the eastern half of the state where surface level smoke has been stubborn and continues to linger in many areas this morning.  We are happy to see many more green ("Good" air quality) shadings in western Colorado.

Fortunately smoke levels should continue to gradually drop off today, but in the meantime we do suggest taking a few extra steps to protect your health (especially for those east of the Continental Divide).  Breathing in wildfire smoke can have lingering health impacts on your body even after the air quality has improved.  This is especially true for those that do suffer from heart or lung disease, older adults, and children.  Please visit our Wildfire smoke and health webpage to get more information on how to best protect the health of yourself and your loved ones.

Western Slope looking much better while one more day to go east of the divide

 A workweek that has been plagued by out-of-state wildfire smoke may have a happy conclusion as the atmosphere finally gets cleaned out.  Step one of the process has already been completed:  the upper level transport winds from the Canadian wildfires have been shut down.  That means no additional smoke is expected to be pushed into Colorado over the next 24 hours.  Check out this morning's visible satellite image compared to the same time on Tuesday.  Note the milky look of Tuesday's image (left), particularly over eastern Colorado.  Eventually all of that smoke mixed down to the earth's surface and impacted the air that we breathe.  That smoke way up in the atmosphere is largely absent today (right).  So instead of particle pollution (PM2.5) increasing today we anticipate it will decrease, albeit gradually.

Visible satellite image at 7:30am Tuesday (left) vs. 7:30am Thursday (right)

However, folks in the eastern half of Colorado are not out of the woods just yet.  There's still quite a bit of smoke out there this morning and it will take some time to decrease.  We are also still dealing with elevated ozone for the Interstate 25 urban corridor including Ft. Collins, Boulder, Denver, Colorado Springs, Greeley, and surrounding areas.  Additionally, we have been breathing air filled with smoke for several days now.  So we are extending our health advisories for the entire eastern half of the state until midnight Thursday night/Friday morning.  Everyone should continue to follow the health recommendations we have been stressing all week -- reduce prolonged or heavy exertion, limit time outdoors, take extra breaks while being outdoors -- particularly for all of our neighbors that suffer from heart/lung disease, older adults, and children.  And for those that consider themselves healthy, it's still not a bad idea to push off outdoor exercise one more day as Friday should be much improved.  Not only will the smoke continue to naturally mix out of the atmosphere, scattered showers and thunderstorms Friday afternoon should finish off the job of cleaning things up.

For our friends in western Colorado, we are already starting to see the benefits of the changing air mass.  Smoke levels are anywhere from 25-50% lower than they were at this time yesterday.  So although we don't suggest running a marathon today in Aspen, Steamboat Springs or Alamosa, it is safer to spend a bit more time outdoors today.  The air quality improvement is expected to continue throughout the day today and into tomorrow.  The one wild card on the Western Slope today is elevated ozone again for the Grand Valley as the smoke has had some influence in the Grand Junction area the past few days.  We expect ozone to be a bit lower today, but we will be watching it closely and will issue another advisory for Grand Junction if needed.

How about the upcoming weekend?  The good news is that we are not expecting the upper level winds to shift back to the Canadian or Pacific Northwest fires.  However, we will need to keep an eye on upwind wildfires in central and southern California, Nevada and Utah.  However, at this point it looks like any smoke those fires produce should be nowhere near what we have seen so far this week.

Transition Day

 Yet another morning of waking up to thick smoke for residents in the eastern half of Colorado.  However, today appears to be a turning point as we begin to see slow improvements.  In fact, those improvements are already occurring across the Western Slope.  Advisory information and a full analysis to come.

A smoky sunrise over Pueblo Thursday morning.  Image courtesy of the Federal Aviation Administration

Hazy, but improved over yesterday, at Yampa Regional Airport in northwestern Colorado.  Image courtesy of the Federal Aviation Administration

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!

An early morning look at the EPA's Fire and Smoke Map reveals fine particulate (PM2.5) concentrations in the Unhealthy for Sensitive Groups category across much of the eastern half of Colorado.  In other words, the smoke hasn't gone anywhere.........yet.  More advisories on the way today and we'll try to provide a light at the end of the smoky tunnel for you.

Widespread smoke across eastern Colorado. Advisories have been issued.

 A steady stream of smoke continues to pour into Colorado from the north.  The heaviest smoke today will undoubtedly be across the eastern half of Colorado with advisories posted for all areas to the east of the Continental Divide.  You can view all of our advisories on our Colorado summary page.  We also highly suggest signing up for our air quality email alerts where you can choose specific counties of which to receive alerts.  

Visible satellite image of Canadian wildfire smoke moving into eastern Colorado.  Image courtesy of the Colorado State University SLIDER satellite page.

Although all of eastern Colorado will be impacted today, we expect the worst air quality to likely be across the northeastern corner of the state (including Julesburg, Fort Morgan and Burlington) westward to the Front Range foothills, including the entire Interstate 25 corridor from Ft. Collins southward through Denver and Colorado Springs to Pueblo.

Let's look at those two areas separately.  In the northeastern corner of the state, we are anticipating the highest particle pollution levels due to having the heaviest smoke.  We expect fine particulate concentrations (PM2.5) to increase throughout the day in this area as heavy smoke high up in the atmosphere mixes down to the earth's surface.  So even though smoke concentrations are already elevated this morning across the northeastern plains of Colorado, if you need to be outside today then this morning is probably the better option from a health standpoint.

HRRR-Smoke model output showing the heaviest smoke concentrations in far northeastern Colorado Tuesday afternoon.

Meanwhile towards the foothills, it will be the combination of particle pollution and ozone that will create health concerns across the urban corridor.  All the larger cities along I-25 from Ft. Collins all the way south to Pueblo will be impacted today.  Similar to the adjacent eastern plains, the air quality is expected to get progressively worse as we move through the day.  So any outdoor activities would be best suited during the morning hours.  Better yet, if possible limit your time outdoors altogether.  Of course that is not possible for everyone, so while outside be sure to slow it down and take plenty of breaks.

The news is not all doom and gloom.  We don't expect the smoke to increase today for locations west of the Continental Divide.  In fact, we might see a little improvement in places like Granby, Steamboat Springs and Craig.  However particle pollution levels will still be elevated, so we don't advise everyone to return to normal outdoor activity levels just yet, especially if you suffer from heart or lung ailments.  We should also note that smoke may increase again across the West Slope on Wednesday as the upper level transport winds try to bring in smoke from Pacific Northwest wildfires, so please continue to remain alert to rapidly changing air quality conditions for the remainder of this week.

How to protect your health from wildfire smoke

Air quality in your area

Another smoky day on the way

 The view from the top of Pikes Peaks says it all this morning with the eastern plains completely shrouded in smoke.  Advisories will be issued this morning, so please stay tuned to this space.

Webcam image from the top of Pikes Peak looking south.  Image courtesy of the city of Colorado Springs Pikes Peak Cameras

Advisories for wildfire smoke have been issued

 Wildfire smoke continues to increase across much of Colorado Monday afternoon.  Although we are seeing light to moderate levels of smoke most everywhere across the state, some heavier smoke can be found in a few areas.  The northern Front Range region (Denver, Boulder, Ft. Collins, Greeley, etc.) is one of those areas that are feeling the impacts of wildfire smoke combining with the normal, day-to-day pollution along the Interstate 25 corridor.  In fact, both ozone and particle pollution are high in this area.  You can find more information at the Front Range/Denver advisory page.  

Meanwhile, we have seen a rapid increase in wildfire smoke across north-central and northwestern parts of Colorado.  An advisory for wildfire smoke has been issued for Moffat, Routt, Jackson and Grand Counties, which includes places like Steamboat Springs and Craig.  Advisory details can be found at the Colorado advisory page.

We may see some gradual improvement across  the northwestern corner of the state on Tuesday, but that will likely not be the case east of the divide.  In fact, even heavier smoke may impact the northern Front Range region on Tuesday along with a wide expanse of the eastern plains.  Please continue to follow this blog as updates will be provided throughout this smoke episode.

In the meantime we continue to urge Coloradans to be vigiliant in protecting their health, especially those of you that may suffer from heart or lung ailments.  You can get information regarding your protecting your health at the  Wildfire smoke and your health webpage and check the air quality for your local area at the EPA's Fire and Smoke Map 

EPA's Fire and Smoke Map shows moderate levels of smoke (yellow) with some areas of northern Colorado now reaching levels of smoke reaching the unhealthy for sensitive groups category (orange)

Obscured visibility at Steamboat Springs Airport due to increasing wildfire smoke.  Webcam image is provided courtesy of the Federal Aviation Administration

Smoke has arrived......and more to come

 The much advertised smoke from wildfires in Canada has arrived to Colorado and unfortunately won't be leaving in a hurry.  Highest smoke concentrations Monday morning appear to be at the higher elevation locales in north-central Colorado, including the Park Range and northern parts of the Front Range.  As evidenced by the below webcam image, Rocky Mountain National Park is already beginning to see the impacts of this smoke.

There is a good chance that health advisories will need to be issued today, particularly for parts of northern and eastern Colorado.  In the meantime, please get familiar with the best ways to prepare yourself and your loved ones for degraded air quality from wildfire smoke at our Wildfire smoke and health webpage.  Additionally, you can monitor air quality in your area with the EPA's Fire and Smoke map.

A smoky view from the Alpine Visitor Center webcam at Rocky Mountain National Park

Increasing smoke statewide expected for the start of the week

 Unfortunately it is becoming increasingly likely that large parts of Colorado will see a noticeable increase in ground-level smoke concentrations over the next 24-36 hours.  To start, surface smoke levels across the northern plains states will be pushed into northeastern Colorado along with locations further southward along the Kansas stateline during the afternoon hours on Sunday.  The good news in these areas that we are also anticipating showers and thunderstorms Sunday afternoon, so smoke will be disbursed and have difficulty getting established due to the unsettled weather.

Canadian wildfire smoke surging into the northern plains states with data provided from the Environmental Protection Agency's Fire and Smoke Map

By Monday, a large increase in smoke aloft high up in the atmosphere is expected across large parts of the state.  This smoke could be noticeable early in the day across the north-central mountains of Colorado, including Rocky Mountain National Park, with the smoke increasing across lower elevation locations during the late morning and afternoon hours.  The heaviest smoke on Monday is expected across the eastern half of the state and could reach advisory levels, so making preparations now for degraded air quality is a good idea.  This is especially true for those that suffer from heart or lung ailments.  First and foremost, if you would like to spend some time outdoors, Sunday is without a doubt your best option for the next several days.  Additionally, checking out Wildfire smoke and health page is a good way to start planning for how to best protect your health as air quality starts to go downhill.

Sunday morning visible satellite image reveals heavy smoke extended from Canada southward into the northern plains states.

Uncertainty remains in surface impacts from transport of wildfire smoke from out-of-state fires

 Upper level winds continue to support expectations that smoke from fires in the northwestern U.S. and Canada will move into Colorado on Sunday and into next week. However, how much of that smoke will be drawn to  the surface remains unclear. Model trends show that the greatest concentrations of smoke aloft will shift from northwestern Colorado toward northern and eastern portions of the state, possibly including the Front Range. Yet a cooler airmass is also on the way, which will bring clouds and showers to the area, and may limit much of the mixing of smoke down to the surface.

Model forecasts from the HRRR-Smoke model at 20-21 UTC (2-3pm MDT) on Sunday, July 21, 2024 show ample amounts of smoke aloft (upper image), with only pockets of light to moderate smoke reaching the surface (lower image) in northeastern Colorado (images courtesy of NOAA-NCEP).

Observations of smoke concentrations have generally agreed with model projections, so currently concerns for significant public health impacts remain minimal, however conditions may change rapidly in areas where vertical mixing enables smoke to reach the surface.

Warmer and drier conditions on Monday, with less cloud cover, may also change the vertical distribution of smoke, and may increase concerns for air quality.

We will continue to monitor this situation as it evolves, and will continue with updates and expectations as impacts become more clear. Those who are sensitive to exposure to smoke (fine particulate matter) should be prepared to undertake health precautions if conditions in your area degrade.

Weekend smoke in Colorado: Where will it be the worst?

 With upper level transport winds continuing to bring smoke into Colorado from fires in the Pacific Northwest, we do anticipate that there will be an increase in particle pollution for much of the state over the weekend.  For Saturday, it appears that the biggest impacts will be in northwestern and west-central parts of the state, so we are giving the heads up to folks in Craig, Meeker, Grand Junction, Rifle, Aspen, and surrounding areas.  Although smoke concentrations are not anticipated to reach advisory levels, it's not completely out of the question so stay tuned to this space throughout the weekend. 

It's likely that smoke will begin to increase in these impacted areas late Saturday morning and continue through the afternoon as the air mass at the earth's surface warms up and taps into the smoke that will be aloft. So if you are planning some strenuous outdoor activities on Saturday in northwestern or west-central Colorado, the earlier the better.

We are still monitoring the situation for Sunday/Monday as we could see an influx of additional smoke from fires in Canada.  More on that as the situation evolves.

HRRR-smoke model output for 1pm MST Saturday

Continued transport of smoke into Colorado, possibly increasing through the weekend ahead, 7/18/24

 Clockwise flow around high pressure anchored over the 4-corners area will continue to support the transport of smoke from wildfires in the northwestern U.S. In addition to this, a trough digging into the Midwest will create a corridor of upper level winds moving north-to-south along the greater Rocky Mountains over the weekend. 

Image of GFS 500mb winds on Saturday, July 20th, 2024, courtesy Weathernerds.org.

    

This pattern is expected to continue the hazy skies and light concentrations of fine particulates that have been seen already, and may gradually increase impacts on air quality by next week. If the north-to-south transport that models are hinting at comes together, there is potential for significant degradation of conditions through the weekend, and into next week.

Image courtesy of NOAA NCEP.

Surface impacts that may result from the upper level transport currently remain uncertain, however there is potential for increasing levels of smoke (fine particulates) throughout Colorado. Updates will continue to be provided as things evolve and expectations become more clear.

More Smoke is Coming to Colorado

 After a few days of relief, smoke is coming back into the picture in Colorado later this week. Multiple large wildfires are burning in Montana, Idaho, and Oregon, producing heavy plumes of smoke in those locations. (See InciWeb for details.)

Thursday, smoke is expected to arrive in Colorado from these large fires to our north and northwest. Northern Colorado is expected to have the heaviest smoke, but light smoke is possible throughout a majority of the state. Hazy skies are also likely Thursday. While no major public health impacts are expected at this time, CDPHE will monitor the situation and issue an Air Quality Health Advisory if necessary.

New wildfire start in far western Colorado

 The Jones wildfire is producing smoke out near the Colorado/Utah state line in western Mesa County.  No public health impacts are anticipated, however you may see some smoke in the sky if you driving west out of Grand Junction on I-70 over the next few hours.

Location of the Jones wildfire in western Mesa County

Improving air quality.......for now

 There has been an overall decrease in the amount of fine particulate matter (PM2.5) across Colorado over the past 24 hours.  This is welcome news along with the decreasing temperatures and an increase in showers and thunderstorms that we are anticipating for today and tomorrow.  However, we will need to monitor out-of-state wildfires closely as we head towards the middle and latter part of this week with the upper-level transport winds potentially bringing an increase in smoke back to Colorado.  Stay tuned.

Continued smoke across Colorado

If you were hoping for relief from the heat or the haze, it's not here just yet. Smoke is sticking around for another day. Most will remain primarily in the upper atmosphere, so expect another day of hazy skies and light to moderate smoke at the surface today. Afternoon highs are again expected to climb into the high 90s and low 100s. The extreme heat can exacerbate the effects of air pollution on the body, so take caution to protect your health. CDPHE's website has resources on how to protect your health during extreme heat and how to stay healthy during a wildfire smoke event. 

The good news? Some thunderstorm activity is possible Sunday afternoon. While it might not be enoough rainfall to water your garden, the shakeup from this stagnant weather pattern could help to clear the air a bit.

One difference today is that a Red Flag Warning is in effect for a large portion of Colorado, and our neighbors upwind (Wyoming, Utah, Idaho, Nevada, and more.) The smoke situation could change if new fires spark. CDPHE is monitoring the situation and will provide updates as necessary. 

Another hazy day in Colorado. This webcam faces west, showing downtown Denver with the mountains in the background. Today, haze blocks the view of the Rockies. (Image from APCD webcam: https://www.colorado.gov/airquality/live_image.aspx)

Quail Hollow Fire Burning Southeast of Byers

The Quail Hollow fire is burning in Arapahoe County, southeast of Byers. Because this fire is burning in low density fuels (brush, grass, etc.) it is unlikely that it will produce heavy amounts of smoke. No major public health impacts are expected at this time. However, unusually sensitive people may consider reducing time outdoors in areas where smoke is present. 

Smoke from the Quail Ridge Fire is visible on satellite. Source: https://rammb-slider.cira.colostate.edu/