California Wildfires

What causes fires to spread?

So. California Is Mountainous

Hot air rises, fanning flames on mountain slopes..

High Winds Blow East to West

Effect of Santa Ana Winds  NASA photo shows smoke plume over Pacific caused by powerful Santa Ana winds in So Cal  The winds fanned the fires and caused their rapid spread  NASA photo shows smoke plume over Pacific caused by powerful Santa Ana winds in So Cal  The winds fanned the fires and caused their rapid spread

In just over 3 hours…

What causes Santa Ana winds?  High pressure area over the Great Basin  Low pressure area over the Pacific  Air from the high flows to the low  The greater the difference between the high and the low, the stronger the winds  High pressure area over the Great Basin  Low pressure area over the Pacific  Air from the high flows to the low  The greater the difference between the high and the low, the stronger the winds

Another Santa Ana Effect…  As the high-altitude winds from the Great Basin sweep down the mountain slopes and descend to sea level,  they warm up and dry out because of the increase in air pressure at that altitude.  That's what makes the Santa Ana winds so withering.

What Causes Increased Hazard?  A wet season, followed by dry season  Brush fires are fiercest when there is lots of dried brush for fuel  A wet spring tends to increase the fire hazard  If a dry autumn follows, that leaves lots of dried brush, ready to burn  A wet season, followed by dry season  Brush fires are fiercest when there is lots of dried brush for fuel  A wet spring tends to increase the fire hazard  If a dry autumn follows, that leaves lots of dried brush, ready to burn

Human Life Choices  Original people who lived in Los Angeles area, the Tongvas, called San Fernando Valley the “Valley of the Smokes.”  To live successfully near the mountains, Californians must learn to exercise awareness of the natural environment.