During the winter, storm tracks move further south.  Wind direction and speed are modified by migratory pressure centers.  With a strong high pressure area over the Great Basin and an intense low pressure area approaching the coast from the west, strong and sometimes damaging winds occur, usually from an easterly or southeasterly direction, especially along the coast and in the coastal mountains.  As the storms move inland the winds veer to southerly and southwesterly directions, and high wind speeds may occur anywhere within the State with the greatest velocities at high elevations.

Under a slightly different configuration of these pressure systems, winds tend to flow out of the Great Basin into the Central Valley, the Southeastern Desert Basin, and the South Coast.  Such wind situations are identified in southern California by the name “Santa Ana Wind.”  The air is typically very dry.  The winds are strong and gusty, sometimes exceed 100 MPH, particularly near the mouth of canyons oriented along the direction of airflow.  It is a situation that occasionally leads to serious fire suppression problems and often results in the temporary closing of sections of main highways to campers, trucks, and light cars.

A similar circulation pattern creates the “northers” of the Sacramento and San Joaquin Valleys.  As a result of compressional heating of air flowing out of the Great Basin this situation results in pronounced heat waves in summer.  In winter the result is usually a rather mild temperature accompanied by a dry, persistent wind that many persons find unpleasant.