Winter rains are essential for life to thrive in the Sonoran Desert.
The Tohono O’odham call them “the mother rains” because their widespread, gentle drizzles nurture the earth and its inhabitants. In contrast, the summer monsoons are called “the father rains” as they are violent, sporadic thunderstorms that bring thunder and lightning and isolated but torrential downpours.
Last year in early March — when I took this photo of the ocotillos out in the Vulture Mountains near Wickenburg — the area had received 4.7 inches of rain over the previous four months. This is almost exactly matches the 30-year rainfall averages for Wickenburg for November through February.
And you can see the desert plants are thriving, showing off their brilliant spring greens. But not every year is like this.
Currently, the desert is under an incredible dry spell. Wickenburg, for example, has received basically zero precipitation in the last two months. But in an average year, it would receive nearly 2.5 inches of rain in November and December.
And this is not uncommon or altogether unexpected either. The winter rains are often driven by the conditions out in the Pacific Ocean, and most often: the water temperature.
This winter the Pacific is showing conditions known as La Niña, which is a cold-water cycle in the Eastern Pacific. This pushes the jet stream north, cutting off moisture supplies in the desert southwest.
We saw the onset of La Niña back in late summer, and knew a dry winter was on the horizon.
For our dear desert plants, it means a time of stress, holding onto what little moisture they have, hoping a rogue storm will break the cycle and sweep through the region.
And for us humans, who mainly (selfishly) just want a pretty, green, wildflower-sprinkled desert come spring — well, we’ll likely be looking at mostly tans and browns for a good while.
Meanwhile, an atmospheric river has absolutely dumped rain on the Pacific Northwest over the last 10 days or so. Send some of it this way, please!
That’s it for today’s Daily Dose! I hope you learned something.
-Jake
Sign up to get the Daily Dose of the Southwest delivered directly to your email inbox every weekday.
