Tuesday, July 17, 2018 - How to see if a smoke plume is actually affecting the air quality at the surface.

Especially during the hot, dry, atmospherically stable periods like we've been having the last few days, smoke from fires can end up aloft above you, but not necessarily be affecting air quality for you at the surface. 

Every day, the NOAA HMS Smoke program examines satellite imagery and draws the smoke plumes you can find on the Airnow Wildfire page (https://www.airnow.gov/index.cfm?action=topics.smoke_wildfires). These plumes appear as the semi-transparent gray areas in the screenshot below of that web page, but they don't tell you whether the smoke actually was there on the ground. 

The nice thing about the Airnow page is that it also shows the monitor (Nowcast) levels so you can see if the smoke plume is actually having an impact on the ground (those dots represent monitors on the ground, and their color represent the Nowcast level of smoke). You can also click on the bar to the right to see the different layers being displayed and turn them on and off.

Map of today's smoke plumes, fire location, and current monitored surface concentrations from EPA's Airnow page. Smoke plumes are drawn based on satellite observations (click here for more details), and the initial HMS product for the current day is created and updated by a satellite analyst roughly between 8am and 10am Eastern Time. After 10am, the analysis is fine-tuned as time permits as additional satellite data becomes available. Areas of smoke are analyzed and added to the analysis during daylight hours as visible satellite imagery becomes available. The product is finalized and "completed" for the archive the following morning - generally by around 800am. Dots on the map represent the level of smoke according to the Nowcast scale, and show if the smoke is actually at the surface in that location.