Intermittent plumes of smoke moving through the Front Range Wednesday afternoon

 As we had expected, smoke that is aloft in the atmosphere and was headed our way this morning is finding its way to the surface in areas of Colorado. In this scenario, the vertical mixing of the atmosphere is both hurting and helping us.

The low-level turbulence caused by warming daytime temperatures and our abundant Colorado sunshine, and its contrast with the relatively cooler air above the surface, is helping to draw smoke downward and is resulting in increases in particle pollution measured by surface monitors. Yet it is this same motion in the atmosphere that is creating a bank of cumulus clouds along the foothills. As the clouds move east off of the higher terrain, cooling is caused by cloud interactions with their surroundings, and helps to produce localized areas of sinking air that spreads out radially once it hits the ground. These areas of breezy outflow winds are helping to limit the overall impacts of the smoke, and are expected to help disperse surface concentrations as the afternoon progresses. Additionally, the clouds help to reduce the amount of surface heating, and decrease the vigor of up-and-down drafts, potentially limiting the amount of smoke that can be drawn down to surface level.

In addition to all of this, the dense plume of smoke that is the root of the issue continues to be fairly discrete, and is moving through the region... with emphasis on the word 'moving.'

Visible satellite image from CIRA shows the presence of smoke moving through the northern portions of Colorado, with cumulus clouds moving eastward off of the high terrain at 1:40 pm MDT on Wednesday afternoon. 

The overall take-away message is that we are seeing increases in particulate levels at several monitors throughout the region, but we expect those numbers to plateau and taper off as the day progresses. So while hazy skies and notable ups and downs in smoke levels are expected and taking place, we do not currently expect these conditions to persist for extended periods of time. 

As the fires continue to burn, additional plumes of smoke will be created and the potential for repetition of this cycle tomorrow does remain. Stay tuned for additional updates as we watch all of this unfold, and we will continue to share our thoughts and expectations.