DES MOINES, Iowa — Around 3 AM in the morning, calls to emergency lines started coming in for the smell of smoke in Downtown Des Moines and nearby neighborhoods. Air quality lowered suddenly around that time due to the smoke, but responders were not able to find a source of the smoke. This shows the air quality sensor results at the Polk County Health Department, just north of Downtown Des Moines.

Wildfire smoke in the upper layers of the atmosphere has been making for hazy and bright orange sunrises and sunsets, but National Weather Service meteorologists cannot say for sure that the source of the smoke in Des Moines was related to that. The reason because the smoke was very isolated to the downtown area when it first developed.

Viewer emails indicated the smoke may be due to large burn piles of driftwood and brush along Saylorville Lake. Jeff Rose with the U.S. Corps of Engineers confirms to WHO 13 that maintenance crews are burning driftwood that has accumulated from the recent high water on the lake. He said that the burning should be finished today.

An inversion is in place over Central Iowa this morning, which prevents air from rising. If the source of the smoke was from the burn piles, it would make sense that the smoke would stay trapped in the low levels and move down from Saylorville along the low-lying areas of the Des Moines River to downtown.

Here’s a look at the 4 AM Air Quality Sensor at the Polk County Health Department. It is in the very unhealthy level (purple). You’ll notice the other sensors in West Des Moines and further on the north side of Des Moines near the east mixmaster still reported good air quality (yellow color) at the same time.

The wind in the early morning was calm for most communities. If there was a breeze, it was only around 3 mph from the east.

This did appear to push the smoke further east through the morning and sensors in West Des Moines started to drop to the Unhealthy range (orange) by 6 AM.

As the sun rose, you could see the low-level smoke among the trees of Des Moines.

The unhealthy air quality also did appear to go down hill just west and southwest of the Des Moines Metro through the morning hours as the air started to move around a bit more.

As winds start to move a bit more, the smoke will continue to dissipate. Wind overall will be very light today from the southeast at 5-10 mph. A stronger wind will kick in later tonight and Thursday.

Check out the entire forecast here.