Location Comparison: San Diego and Seattle

San Diego California and Seattle Washington have some similarities when it comes to their weather. First they are both located on the west coast of the United States meaning that the cool Pacific ocean currents impact both locations in addition most of the precipitation in both locations occurs in the winter months although Seattle sees much more precipitation. Both locations also experience the weather phenomenon termed the "Pineapple Express" which is a fairly constant stream of moisture that comes from Hawaii. This is characterized with a precipitation pattern that can last for as much as a week, although those that live in Seattle would say that this lasts all year long! That is where the similarities end. The average annual temperature in Seattle Washington is around 52 degrees a full 12 degrees lower than that of San Diego California at an average annual temperature of 64 degrees. When comparing the climate graphs of both locations it can be seen that San Diego has a more moderate climate with a smaller difference in monthly high and low temperatures than that of Seattle. In addition the climate graph for Seattle seems to show more continentality meaning there is a fairly large range in temperatures from season to season. This explains the occasional snowfall in the winter months, which is very rarely seen in Southern California.

source:http://drought.unl.edu/archive/climographs/SanDiegoANC.htm

source:http://drought.unl.edu/archive/climographs/SeattleANC.htm

snow covered Cuyamaca Mountains east of San Diego

Air Masses and Weather Patterns

San Diego and Southern California in general are impacted primarily by maritime tropical(mT), and continental tropical(cT). Wintertime in San Diego is generally cool and wet which means that during this time of year the area is mostly affected by maritime tropical air masses accounting for most of the precipitation received throughout the year. On the other hand summers are much different with warm and dry conditions which can be attributed to the predominately continental tropical air masses with occasional maritime tropical air masses bringing some summertime precipitation. Mid-Lattitude cyclones do affect San Diego with primarily warm, cold, and warm occluded fronts. when it comes to occluded fronts the warm type is only seen on the west coast of North America including San Diego. Current conditions show that a weak cold front has recently passed by not affecting temperatures too much as the a San Diego is experiencing a seasonal high of around 60 degrees for today and even warmer in the days to come.

source:http://www.weather.com/maps/maptype/currentweatherusnational/uscurrentweather_large.html

One weather feature unique to San Diego and Southern California is the "June gloom" this is generally characterized by a thick marine layer that is present mainly along the coast while it sometimes ventures inland. This is due to warm moist air masses moving over the cool ocean currents which causes an inversion and in turn forming a "lid" in the atmosphere trapping these low lying clouds. Generally this inversion is lifted in the afternoon as the sun heats up the atmosphere. This can put a damper on your hopes of enjoying a nice sunny day at the beach so plan you vacation accordingly!

source:http://weathersandiego.blogspot.com/b/post-preview?token=Bt87hjYBAAA.g8qfHXhcy2_n_AnElkAs9w.IYoqJ7sHWz0Hwv8RmxnrEA&postId=8608715569712052574&type=POST

Typical "June gloom" as you can see it generally hugs the coast.

source:http://gocalifornia.about.com/od/calamenu/ig/Manhattan-Beach-Pictures/June-Gloom.htm

This is what you can come to expect in June along the coast.