Summer usually brings hot, dry weather and elevated wildfire risk to the western United States. Summer 2015 was no exception. As of August 17, outbreaks of large wildfires had charred nearly 7 million acres, nearly two million more than the ten-year average through mid-August.

While 73 percent of the burned area is the result of massive fires in remote forests in Alaska, large blazes have emerged in the Pacific Northwest as well. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this true-color image of several fires burning in Washington, Oregon, Idaho and California on August 20.

Red outlines indicate hot spots where the sensor detected unusually warm surface temperatures generally associated with fires. Thick plumes of smoke drifted from the hot spots.

One of the most destructive fires, the Kettle Complex, burning in the Colville National Forest in Washington had consumed 56,208 acres as of August 24, and was only 15% contained. It was ignited by lightning strike on August 11, and was being worked by 800 personnel. It is burning in timber, grass and brush. Full containment is not expected until October 15. Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC Click to enlarge.

Today's Weather Activity

Welcome to JetStream, the National Weather Service Online Weather School. This site is designed to help educators, emergency managers, or anyone interested in learning about weather and weather safety.

The information contained in JetStream is arranged by subject; beginning with global and large scale weather patterns followed by lessons on air masses, wind patterns, cloud formations, thunderstorms, lightning, hail, damaging winds, tornados, tropical storms, cyclones and flooding. Interspersed in JetStream are "Learning Lessons" which can be used to enhance the educational experience.

You are free to use the materials in any manner you wish. We welcome your feedback on this project. Your input will greatly assist others in teaching the "hows" and "whys" of weather. Not sure where to begin? Click to see all topics in JetStream in the Topic Matrix. Contact Us:

Steven Cooper
Deputy Regional Director, NWS Southern Region Headquarters, Fort Worth, Texas

Dennis Cain
a.k.a. "Professor Weather", NWS Fort Worth, Texas