Vince_Condella's Blog

California:  nice place to visit but I wouldn't want to live there.  That's what a kid from the Midwest like me thinks of our most populated state.  With over 36 million people living within its borders, the left coast has a wealth of natural resources that are constantly under stress and strain.  Sometimes too wet after being pounded by Pacific storms, other years leave it in a drought with reservoirs drying up.  Then there are the famous earthquakes.  This weekend it is the Santa Ana winds fueling wildfires.

Thousands of acres have burned and multi-million dollar homes have gone up in smoke the past few days as winds roared over 70 miles per hour.  These gales simply fan the flames and send hot embers travelling over a mile and allowing them to ignite fires downwind.  This has been a true nightmare for the residents as well as the brave and tireless firefighters.

The Santa Ana winds are named for the Santa Ana mountain range just east of the Los Angeles basin.  Clockwise winds around high pressure over the Great Basin (Nevada, Utah & Colorado) produce an east wind at the Earth's surface that pushes between the narrow mountain passes.  When the wind is forced through a narrow opening, it accelerates.  You feel the same thing when passing between two buildings on a windy day.  (This is know as the Bernoulli's principle, named after Dutch-Swiss mathematician Daniel Bernoulli.)

High pressure over the western U.S. can create east surface winds that squeeze between the passes of the Santa Ana mountains.

Not only do the winds speed up through the mountain passes, they then descend down the west slope of the mountains and into the LA Basin.  As they move into lower elevations, gravity is greater, squeezing the air parcels and causing them to heat up by compression.

The result of atmospheric physics and thermodynamics is a hot, dry wind leaving misery in its path.  Our thoughts are with those in the LA Basin tonight.