Downslope Winds Fan Western Fires

Downslope Winds Fan Western Fires

A weather front that drew unseasonably cold air into the Rocky Mountains also set up an atmospheric pressure gradient that sent dry, gusty winds barreling down the lee (downwind or sheltered) slopes of mountain ranges in several western states. The powerful downslope winds, sometimes called foehn winds, have fanned dozens of wildfires in Washington, Oregon, and California. (Other regional names for foehn winds include Santa Ana, Chinkook, and Mono winds.)

On September 8, 2020, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural color image of thick smoke plumes streaming west from a long line of intense fires.

NASA Earth Observatory image by Lauren Dauphin, using MODIS data from NASA EOSDIS/LANCE and GIBS/Worldview. Caption by Adam Voiland.

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