The Station Fire was a devastating wildfire that began in the Angeles National Forest on August 26, 2009 and was finally fully contained on October 16, 2009. Hot, dry weather conditions worked against the efforts of firefighters. It was determined to be an arson fire that killed two firefighters and injured 22 more people. The maximum wind speed the day the fire began was 15 miles per hour. A mild wind, but just enough to move the fire up to higher slopes. The winds throughout the ordeal were all blowing south, towards the direction of rays from the sun.
At the higher elevations of the Angeles National Forest the denser trees trapped heat easier than the brush at the lower elevations of the forest. This made fire suppression very difficult for the crews on the scene compared to the more common Southern California brush fires. According to Auburn University, slope affects fire in two ways. On a windy day, winds tend to blow up-slope as they let off heat and cool off in the higher elevations. During a wildfire, this wind will carry the fire up-slope along with it. The wind will also carry hotter temperatures and kindle in order to "pre-heat" higher elevations before the fire reaches those areas. Up-slope winds can be as fast as 5-10 miles per hour, a pace that is very fast for firefighters to keep up with.
Once the fire reached elevations higher than 1000 feet, it spread more quickly. For example, in the map above, the fire spread 7.406 miles on the August 30, 2009 00:25 from the previous measurement on August 29, 2009 14:55. In the day prior, the fire had spread a paltry 2.1 miles at the lower elevations. According to Weise and Biginer, a fire burning up-slope shows the "highest rates of spread, greatest potential for damage, and greatest difficulty to control."
The aspect, the way the slope faces, is also critical in determining the effects of a wildfire. How much heat the wildfire receives from the sun can determine how much control firefighters will have in containing the fire. Slopes that face south receive the most intense solar radiation, thus reducing the amount of humidity, faster evaporation, and warmer temperatures. Because of the lack of moisture, most brush is dry and good for fire kindle. The majority of the mountains in which the Station Fire took place in were Southward facing.
According to Butler et al, the size of the fire increases as the slope increases with wind being the dominant variable. Their experiment also emphasizes the importance of preheating the kindle ahead of the spread of the fire. Since the kindle is preheated, the resulting fire is uniform, without gaps firefighters could use to kill the fire in an easier manner. Instead, the firefighters must face a wall of flames burning at the same temperature.
"InciWeb the Incident Information System: Station Fire." InciWeb November 10, 2009. http://www.inciweb.org/incident/1856/
"Topgraphy's effect on Fire Behavior." Fire at Auburn University December 1, 2011. https://fp.auburn.edu/fire/topos_effect.htm
"History for Burbank, CA." Weather Underground December 5, 2011. http://www.wunderground.com/history/airport/KBUR/2009/8/26/DailyHistory.html?req_city=Glendale&req_state=CA&req_statename=California
Butler, B.W., W.R. Anderson, and E.A. Catchpole. "Influence of Slope on Fire Spread Rate." The fire environment—innovations, management, and policy; conference proceedings (2007) 26-30. http://www.fs.fed.us/rm/pubs/rmrs_p046/rmrs_p046_075_082.pdf
Weise, David R. and Gregory S. Biging. "A Qualitative Comparison of Fire Spread Models Incorporating Wind and Slope Effects." Forest Science 43, no 2 (1997). http://www.fs.fed.us/psw/publications/weise/psw_1997_weise000.pdf
