Welcome, in this introduction to the world of Dragon Earth we’ll be taking a look at the city of San Diego, and how the area’s climate shapes it and the surrounding metropolitan area.



The city of San Diego, in the state of California, is located at the southwestern corner of the United States. It is a city of over 1,000,000 people. It is also the center of a binational metropolitan area with a popular of around 5,000,000. Most living in the Republic of Mexico.



San Diego is a port city, with rail connecting it with Los Angeles to the north, and by air to the world. Highways head north, east through the mountains, and south to Mexico. It is also a center of scientific and arcane research, the home of both a zoological garden and a marine park, and miles of beaches and seaside cliffs.



But that’s all beside the point.



What matters here is the area’s climate, and the associated weather. So what sort of climate does San Diego have? That depends. Along the coast it is mediterranean. Much like the coast of Algeria and southern Spain. In the mountains it becomes more temperate, and further east in the desert it becomes down right arid. Depending on where you are, the local temperature can range from near 0º fahrenheit (the mountains in winter) to 120º (high desert in summer).



The key to San Diego’s climate lies in the rain. Or, rather, the lack of it.



The area lies in latitudes that receive little rain throughout the year. Indeed, for most of the year it gets no rain at all. At other times what rain San Diego gets falls in the mountains, at the higher elevations. A relatively common phenomenon is virga, rain that evaporates before reaching the ground. When rain does fall it most often arives in late autumn through early spring.



Now, being a coastal city you’d expect San Diego to get rain coming in off the sea. The city does get clouds early in the morning and late in the evening, (as a matter of fact, the period between late May and late July sees overcast sky nearly constantly) but precipitation from such is rare. When it does occur it is most often because of some triggering event (a lightning flash or a cold snap), or because the air has become so saturated it can’t hold the water any more. A very rare event. The great majority of what rain does fall comes thanks to two storm tracks.



The first is commonly known as, “The Pineapple Express”. This is a body of saturated air that travels eastward from the Hawai’in islands to the US mainland. It does not occur every year, but when it does it can bring heavy rain to the North American continent. Most often to the city of Tijuana, Mexico; which is part of the San Diego metroplex. San Diego is often bypassed. Still, when it is hit the rain can be short and heavy, resulting in severe local flooding.



The second comes from the north, from the Gulf of Alaska. There great storms form and head south and east. Most often they come ashore at or near Vancouver Island, Canada. As a result the region is home to a vast temperate rain forest.



The storms then head east, across the Sierra Nevada and Rocky Mountains to the Great Plains. But some offshoots head further south, to come ashore somewhere along America’s Pacific coast. Most of the time the rains reach as far south as the Los Angeles basin. On rare occasions they get as far as San Diego.



Sometimes a tropical storm will send tendrils of rain as far north as San Diego, but such are rare and cannot be relied on. Those that do are usually the remnants of a Pacific hurricane. The last time a tropical storm actually got to San Diego’s latitude, it came up the Sea of Cortez (in the Gulf of California) and struck Imperial County in south-east California. As you might have guessed, there was severe flooding and great financial loss.



There you have the problem. Most of the time the rain headed San Diego’s way ends up going somewhere else. So at low altitudes it is a largely arid place, requiring imported water to support its sizable population.



It is important to keep this in mind, for it will inform the rest of the series. Why the native humans and orcs lived the way they did before the coming of the Spaniards. Why the city developed the way it did, and why the local elf and dwarf populations remain so low. In addition it will help explain local lizardman customs and beliefs.



San Diego. Not a true desert city, not when you consider the amount of rain the mountains receive, but not the best watered place around.



Tomorrow, a brief look at the physical geography and the arrival of the first sophonts to the area.



Alan