Comparison of the Weather in LA to the Weather in Milan, Italy

I based this comparison on the Milan, Italy weather blog by Alina Yurievna Shemetova.

Los Angeles is located on the coast of California while Milan is located in the interior of Italy.  Both cities are in close proximity to mountains.  The San Gabriel Mountains just east of Los Angeles and the Alps located just north of Milan.  Due to the geography of the two cities, they experience inversions along with smog from the pollution.

 Los Angeles is generally warmer than Milan on average.

 (Source: weather.com)

 Milan averages more precipitation than Los Angeles on average.

(Source: weather.com)  

  

Maritime Tropical and Maritime Polar are the air masses that affect the weather in Los Angeles.  Milan on the other hand is affected by many different air masses: Maritime Tropical, Maritime Polar, Maritime Arctic, Continental Tropical, and Continental Polar.

Milan will commonly experience snow in the winter while snow is relatively uncommon in Los Angeles.  Milan is located at a higher latitude and is affected by much colder air masses than Los Angeles.

Air Masses Affecting LA

Los Angeles is affected by the cooler air masses that come inland off the Pacific Ocean and the warmer air masses coming from the desert.  This often leads to an inversion layer.  The marine atmospheric boundary layer forms with the inversion in place.  The marine layer is a layer of cool, moist maritime air with the thickness of a few thousand feet immediately below a temperature inversion.  The inversion layer traps the carbon emissions from the city and this causes the smog that is often associated with Los Angeles.

(Source: http://www.theweatherprediction.com/weatherpapers/109/index.html)

Source: http://rst.gsfc.nasa.gov/Sect14

 Marine Layer at LAX

My personal photo taken October 23, 2011

In addition, Los Angels is affected by the seasonal Santa Ana winds that blow in the fall, winter, and spring, peaking in December.  The wind usually has its origin when cold air spills southward into the Great Basin, trapped between the Rockies to the east and the Sierras and Southern California coastal range to the west. This cold air mass is characterized by unusually high pressure near the land surface. Winds are driven into Southern California when the pressure of this interior air mass exceeds the pressure along the California coast.

(Source: http://meteora.ucsd.edu/cap/santa_ana.html)

Source: http://meteora.ucsd.edu/cap/santa_ana.html