A fire that burned on both sides of the Missouri river forced residents to evacuate from an area in St. Joseph, Missouri on Sunday. Fire personnel believe the fire started in Elwood, Kansas and jumped the river, spreading over hundreds of acres and for about five miles along the river near St. Joseph. The fire is much less active today, but the area is under a Red Flag Warning.
We checked Google Earth and found that the river in that area is about 0.16 miles (820 feet) wide. Depending on the vegetation, weather, and topography, it is not unusual for burning embers to start fires quite a distance from the main fire. There is a trial going on now in San Diego County that revolves around a fire that may have been ignited by an ember that traveled 0.44 miles and started a new fire that destroyed 36 homes in San Marcos, California. And last September on the King Fire near Pollock pines in California an ember started a spot fire approximately 2 miles ahead of the main fire front. There have been reports of spot fires starting even farther away.
UPDATE, March 17, 2015: It took me a while to find this. It is in a report about bushfires in Australia, “Report on the Physical Nature of the Victorian Fires occurring on 7th February 2009“. It not about burning embers, but lightning caused by the fire.
In 2003, lightning induced by a pyrocumulus cloud started fires in the Snow River National Park, 25 km [15 miles] ahead of the fire front. These fires did develop into a significant area. Other examples exist of this phenomenon.
There’s a great Research Paper that fire guru Hal Anderson did back in the late 1960s on the Sundance fire. Here’s the Link: http://www.treesearch.fs.fed.us/pubs/32534
It took me a while to find this. It is in a report about bushfires in Australia, “Report on the Physical Nature of the Victorian Fires occurring on 7th February 2009“. It not about burning embers, but lightning caused by the fire.
I believe the Sundance fire in Idaho may hold the long distance spot fire record at 10 miles. Hal Anderson wrote a paper on the fire behavior of this fire the next year, 1968.