Wildfire smoke remains in the forecast for many

 Most of Colorado is experiencing at least moderate levels of smoke Thursday morning.  The heaviest smoke can be found in close vicinity to wildfires in western parts of the state, while the Colorado River Valley between Gypsum and Vail is also seeing highly elevated levels of fine particulate matter.

Wildfire smoke producing moderate (yellow) to unhealthy for sensitive groups (orange) levels of fine particulate matter Thursday morning.  Map and data courtesy of the EPA's Fire and Smoke Map

Unfortunately Red Flag Warnings blanket the western half of Colorado on Thursday.  The primary threat will be dry thunderstorms which could initiate new fires and perhaps enhance current fires due to gusty winds.  CDPHE meteorologists will be closely monitoring for new wildfire starts throughout the day.

Counties shaded in pink are under a Red Flag Warning on Thursday.  Image courtesy of the National Weather Service GIS Viewer

The Air Quality Health Advisories that were in effect yesterday will be extended through at least Friday morning, but there will be some changes.  We do anticipate the Lee fire and the Crosho fire to remain active today and send smoke downwind to the northeast.  This will increase the potential for smoke in places like Steamboat Springs and Walden Thursday afternoon.  The highest smoke impacts will remain for areas along and north of Interstate 70 in northwestern and north-central Colorado.  Meanwhile, we do anticipate some gradual improvement for areas a bit further to the south and west, including Grand Junction, Delta, Montrose and Gunnison.  Those areas have been removed from today's advisory, but locals should still take it a little slower than usual as the recent exposure to smoke could have some lingering health impacts.

Meanwhile in southwestern Colorado, the Stoner Mesa fire continues to burn in eastern Dolores County.  This area is also under a Red Flag Warning and could see some growth today, especially if it is impacted by gusty outflow winds from dry thunderstorms.  One small piece of good news is that the transport winds are not particularly strong today in southwestern Colorado, so we are not expecting smoke to move very far away from the fire.  Therefore, air quality should improve somewhat in places like Telluride, Ouray and Silverton.  The flip side is that we are seeing increasing amounts of drainage smoke.  This is the smoke that flows downhill during the early morning hours and generally is at its worst right around the morning rush hour. Cortez and Durango have both seen an uptick in smoke over the past 24 hours.  Though these areas should see some improvement Thursday afternoon once the atmosphere heats up, smoke could very well return late Thursday night into early Friday morning.

Surface smoke at Cortez Municipal Airport Thursday morning. Image courtesy of the Federal Aviation Administration

Below is a map of Colorado showing active Air Quality Health Advisories.  With the rapidly changing atmospheric and wildfire conditions, we urge you to remain up-to-date on current advisories by visiting our website and signing up for email alerts.

Current Air Quality Health Advisories, by county.  Map from Colorado Department of Public Health and Environment, Air Pollution Control Division website