Geography and Climate

As you have likely heard, we are getting pummeled by rain in California. We are located at the southern edge of the band of moisture, so it hasn't been as bad here, meaning that we are getting only a few inches per day instead of 4-5. I've been trying to convince myself to go do some shopping and hit the gym, but with the wind howling and the rain coming down in sheets I just can't seem to motivate myself. I went to weather.com to see if there was a break coming, as unlike further north of here, we have been having occasional breaks. Watching the satellite map gives the best illustration of rain shadow that I have ever seen.

This is a still from earlier this afternoon. As the video runs through the images you can watch the weather cells head north-east. That blue band in Northern California is snowfall in the Sierra Nevada Mountains. The moisture just stops there. There is no precipitation on the back side. At their southern edge, just north of Bakersfield you can clearly see that without the mountains to block it, the moisture just continues across the states. As you head into Eastern Nevada the rain shadow clears and precipitation begins again until the system hits the Wasatch Mountains in Utah. The southern part of the system almost slides south of a the Wasatch mountain range, continuing to drop a little rain until it dumps snow on the Colorado Rockies.

Keeping in mind that the general pattern of winter storms in the west is to travel south-east, it becomes obvious why the American Southwest is a giant desert. This entire area lies in the south-east shadow of the Cascade Mountains and the Sierra Nevada Mountains.