File:Southern California Shrouded in Smoke (MODIS 2021-09-28).jpg

English: Lightning strikes in tinder-dry forests and grassland ignited two significant—and smoky—fires in Sequoia National Park and the Tule River Reservation on September 9-10, 2021. More than two weeks later, the wind-fueled blazes have spread and grown more intense, threatening groves of giant sequoias, prompting authorities to issue evacuation orders, and shrouding Southern California with smoke.

On September 26, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of smoke pouring from the Windy River and KNP Complex fires. Not only is the ash-colored smoke so thick that it many areas it obscures the land from view, but the plume also stretches over part of a broad bank of marine stratocumulus clouds in the west and across Nevada in the east.

Red “hot spots” mark areas where the thermal bands on the MODIS instrument detected high temperatures which, in this case, are actively burning areas. The KNP Complex sits north of the Windy Fire. Hot spots sit along the active edges of the fires; in the center, the fuel has already been burnt and no large fire can be supported. The KNP Complex was first reported on September 10 and was originally two separate lightning-ignited fires. They were joined into the Complex on September 11. The fire has continued to expand in the Sequoia and Kings Canyon National Park and spread northeast into the Sequoia National Forest. As of September 27, the fire has scorched 46,976 acres and is only 8 percent contained. Over 1,800 personnel are combating the KNP Complex.

The Windy Fire, ignited on September 9, has grown to 85,383 acres as of September 27. That’s a 3,105-acre increase from the estimate on the evening of September 26, according to InciWeb Incident Information System. It is burning in the Tule River Indian Reservation; the Sequoia National Forest, including the Giant Sequoia National Monument; and Tulare County and state responsibility areas. As of the evening of September 27, it remains only 2 percent contained.