Arizona surprises in many ways. I’m not addressing it all here. But I will address people’s amazement for the fact that Arizona can be very green. It even snows here.
This amazement results from a lack of familiarity of Arizona’s topography, and a basic understanding of weather dynamics. Let me explain. Let me use maps and photos.
Look at the map of Arizona. The dark area circled red, which covers over 20,000 square miles, is a massive ponderosa pine forest. Entering this forest near Flagstaff, after ascending from Sedona, is particularly provocative to people’s imaginations. They are not expecting this.
But I wanna start in Southern Arizona. Here people really don’t expect to see pines and snow. The weather dynamics around Tucson also operate in the north. So let’s look at those dark spots circled red around Tucson.
They too are mostly pines. The trees contrast starkly with brown desert at the base of those mountains where no trees grow. How is it that islands of trees – or sky islands on the mountain tops – can grow in the desert?
Simple. It’s a result of the land and sky communicating with one another to create highly localized weather patterns. Something called orographic lift causes those weather patterns.
Orographic lift is simple. Air masses are elevated into elevations of the sky where they become less dense for the less air on top of them. Air less dense drops in temperature. Air less dense cannot hold as much moisture. Thus, whatever moisture that is in those elevated air masses more easily condenses into clouds and, given enough moisture, rain.
X volume of moisture in the air masses at the base of the mountain cannot cause clouds and rain. But volume X, orographically lifted to 10,000′ above sea level, can. High country makes the rain.
Thus, tall mountains rising out of the Southern Arizona deserts are topped with trees. Above the saguaro-studded desert around Tucson rise the Catalina Mountains where there can be enough snow in winter to open the furthest south ski runs in the United States.
Now let’s go back to that huge forest in Northern Arizona. That forest exists because the average elevation across this area is over 6,000 above sea level. Orographic lift across this entire area causes it to receive rain and snow, and thus grow pines, and thus amaze people for seeing a side of Arizona they didn’t expect.
The drive from Sky Harbor airport at Phoenix to the Red Rocks surrounding Sedona allows a driver to go from the desert to the grasslands to the pinyon-juniper country. Going up the Oak Creek Canyon from Sedona to Flagstaff introduces you to the ponderosa pines. At the top of Oak Creek Canyon people’s amazement at the stunning change in ecology most strikes them. It’s here where most express that they had no idea what Arizona is really like.
Then they see snow on the San Francisco Peaks north of Flagstaff, even in July, and their amazement is augmented.
Thus, in closing, the romance of the rise from the desert to the pines across this wonderland of a state brought me here as much as the Red Rocks and Grand Canyon. The Good Lord took his time juxtaposing such amazing scenery in Arizona, and I just felt like sharing this little tidbit.