Late night smoke for Steamboat Springs?

 Widespread wildfire smoke continues to plague the northern Front Range region Thursday afternoon, and likely will be sticking around into Friday as well with the Action Day for Multiple Pollutants set to be extended through at least 4pm Friday.  Residents along the I-25 urban corridor, including Denver, Boulder, Ft. Collins and Greeley, should continue to take those extra steps to protect your health from wildfire smoke by limiting time outdoors, if possible, and while outside taking some extra breaks.  But the pollution is certainly not uniform across the area.  Locations in closer vicinity to the wildfires are seeing much higher particle pollution levels, and hence are receiving more concerning public health impacts.  As of 2:00pm Thursday afternoon (see image below), the heaviest smoke is located in Longmont, Niwot, Boulder and into northwestern parts of the Denver metro area.  These areas will likely continue to be impacted Thursday night and Friday morning, with a distinct possibility that the smoke could locally get even heavier (especially in Longmont) as smoke drains down from the Stone Canyon Fire. Also, please don't let your guard down in Loveland and southwestern parts of the Denver metro area.  Although air quality has improved marginally today as atmospheric mixing increased, smoke could increase again later on tonight as smoke drains from the Alexander Mountain and Quarry wildfires, respectively. 

What about the rest of Colorado?  For the most part, it's not too bad out there Thursday with generally light to moderate levels of particle pollution from some remnant light smoke.  However, there have been some indications with smoke modeling that a plume of smoke from the Front Range fires may get up and over the Continental Divide and settle into north-central Colorado overnight.

HRRR-smoke model for total column smoke at 11pm Thursday evening

Is this really going to happen?  Hard to say, unfortunately.  Although it looks fairly likely that smoke currently up in the atmosphere over the Front Range fires will push to the northwest towards north-central Colorado overnight, there is less confidence that smoke will be able to mix down to the earth's surface and create public health issues. 

Regardless, it's probably not a bad idea to shut your windows before you go to bed tonight in Walden and Steamboat Springs, and throughout Routt, Jackson and Grand Counties.  We will certainly provide updates as necessary while the situation continues to evolve.