Meso and Micro Scale Climate

There are several factors that impact the mesoscale climate of southern California and specifically San Diego. These include orographics the proximity to the pacific ocean. For the most part San Diego sits in an area with many orographic features that affect the regional climate. These features include canyons and valleys with the creating a very uneven and hilly environment. These local variations in topography can create a lot of orographic lifting. In the winter months when there is a predominately westerly wind pattern bringing moist pacific air these orographics provide lifting of air masses causing large precipitation events. In the summer months this wind pattern shifts and brings dry warm air from the inland deserts of the western states. Any moisture left in these air parcels is squeezed out from the several mountain ranges to the east creating very dry conditions not typically associated with an area located so close to a water body. These dry warm winds race west across the area sometimes reaching 100 miles per hour and can cause havoc starting wildfires that in recent years have devastated areas in and around the San Diego area. The picture below shows how impactful these wind patterns, labeled the Santa Anna winds, can be.

source:http://interwork.sdsu.edu/fire/purpose.htm

The most predominate micro-scale climate aspect of San Diego would have to be the fairly drastic temperature variation from the coast to the inland. It is pretty obvious that this is created by the proximity of the cold water currents off of the pacific coast. This cool air can only penetrate several miles inland while areas several miles further inland don't benefit from this cooling effect. This requires the local forecasters to delineate temperatures between the coast and areas further inland.

It can be seen that for the most part there is not a drastic change in the average min and max temperatures for both January or July. With that in mind there is a much greater difference in the average max and min for the month of January. This is most likely due to the fact that the weather in the winter months is much more unpredictable than that of the predominately dry and warm summer months. The Koppen-Geiger climate classification for that of San Diego is a Bsk cool steppe, however San Diego can also be classified as a semi arid Mediterranean climate or Csa as it sits on the edge of both variations of climate.

source:http://snow.cals.uidaho.edu/clim_map/koppen_usa_map.htmsnow.cals.uidaho.edu/clim_map/koppen_usa_map.htm