Wind is all around us, constantly playing an essential role in life across California and on Earth. But what is wind and what forces are responsible for moving the tons of air that become gentle beneficial breezes or destructive deadly windstorms? Why are our transitions between seasons so frequently punctuated by windy periods?
It’s invisible, underestimated, misunderstood, and often taken for granted. It transports and directs air masses, storms, moisture, clouds, smoke, dust, and sand. It glides over ocean and lake surfaces, generating waves (see our earlier website story about waves). It spreads pollen that helps propagate plant species and carries odors that animals must follow for survival. Insects, birds, and planes must fly into and through it. It can set the day’s moods: refreshing here, maddening there. It can nurture life and then destroy it in an instant. We could never give wind enough credit for rocking our world. No wonder we have assigned such colorful and descriptive names to winds common to Californians: Diablo, Santa Ana, Sundowner, Mono, Washoe Zephyr, Sierra Wave, Palmdale Wave, etc. … and even shared their stories on our website and in our book. The wind keeps us guessing with its wild mood swings and leaves us on the edges of our seats with its entertaining performances: swirling, dancing, rustling, whispering, singing, moaning, and howling, And then it vanishes and gives us the silent treatment.
How fast can winds blow across the Golden State? Recent records have been set, thanks to increasing wind speeds and our improved technologies to measure them. It is not surprising that records fall when strong currents are forced to skim over the state’s highest ridges and peaks, mostly in the Sierra Nevada. During the powerful atmospheric river that swept the state on February 4-5, 2024 (see our recent website story), a 162-mph gust was recorded at Ward Mountain (8,643 feet asl), above the Tahoe Basin. During the same storm, a 148-mph gust blasted across nearby Palisades Tahoe (8,700 ft) while a 125-mph gale roared past Mammoth Mountain. This was part of a massive and destructive windstorm that ravaged Northern California from the coast to the mountains, knocking out power to nearly one million people. Just weeks later, on March 1, 2024, a 190-mph gust swirled over Palisades Tahoe during the historic blizzard that is summarized in this story with weather maps. But none of these have yet eclipsed the NWS official 199-mph confirmed record set at Ward Mountain Palisades in 2017. Several records over 150-mph have been set on other peaks and ridges, but those above 8,000 feet looking down on the Tahoe Basin are the consistent Golden State winners. (California wind records can’t compete with the US wind speed winner: Mt Washington in New Hampshire at 231-mph.)
We all share memories of how windstorms interrupted or changed our lives when the gusts reshaped landscapes and damaged infrastructures around the places we call home. My mountain neighbor Steve Chadwick, who also spent ample time living in the desert, reminds me how windstorms occasionally blow sand across Coachella Valley roads. He and other residents have watched several desert roads (Gene Autry Trail and Indian Canyon Drive are examples) disappear below the shifting sands. After each event, the buried roads-turned sand dunes must be closed until sand plows (think snow plows) clear the way. Up on the nearby mountain around Idyllwild, power is interrupted when windstorms knock branches and trees down on to utility lines. Today, power companies across California are busy year-round clearing branches and dead trees away from their lines that may threaten to ignite the next deadly wildfire. Still, life on Earth requires wind and Steve was also quick to remind me how tons of dust blown from the Sahara are essential to the health of the Amazon. Here is a fascinating NASA article that summarizes this discovery.
The big wind show starts with a pressure gradient force. Because wind always wants to blow from relatively high atmospheric pressure to low pressure (at the same altitude above sea level), air flows. The breeze or wind you sense is the force of billions of air molecules per cubic centimeter racing out of high pressure and into low pressure systems. When strong high- and low-pressure systems are positioned very close to one another, there is a steeper pressure gradient that will energize stronger winds. By contrast, when there is little or no difference between high and low air pressure around you, the wind will remain calm. Since pressure systems are constantly strengthening or weakening and migrating, wind velocities are always changing. The billions of air molecules you feel and breathe have likely traveled thousands of horizontal miles and thousands of vertical feet (or meters) to get to you. They are sailing messengers announcing how our dynamic atmosphere is fluctuating and what changes you might expect in the future.
Because Earth turns under this air set in motion, the Coriolis effect will also kick in. The wind will be turned to its right out of high-pressure systems in the northern hemisphere and also nudged to its right as it flows into low-pressure systems. Add friction near Earth’s surface and the pressure gradient force will gradually win this windy tug-of-war. This is why winds spin clockwise out of high pressure anticyclones (fair weather systems) and counterclockwise into our northern hemisphere low pressure cyclones or storm systems. (Note that winds turn and spin in opposite directions when pouring out of highs and into low pressure systems in the southern hemisphere.) Looking for more details about these pressure patterns and winds? Check out the weather maps at the end of this story and then our new California Sky Watcher publication.
There is much more to this aeolian story, but you can see why spring can be a breezy season. Extreme temperature gradients can bolster strong pressure gradients as warm summer air masses encroach upon winter’s stubborn cold air masses. Sporadically and unevenly, summer will win this annual war, but not without some windy battles. Additionally, as the longer days and higher sun angles rapidly warm inland land surfaces, the progression through spring encourages onshore breezes. Air will begin expanding and rising above those heated land surfaces, creating thermal low pressure there that will suck in the cooler, denser air that forms above our cold ocean currents. Sea breezes and their marine layers will begin to dominate weather conditions along the coast well into summer. Mountain barriers represent massive blockades, except for the few canyons and passes that become narrow wind tunnels where coastal air masses attempt to squeeze inland. You will find some of our largest wind turbines – producing energy for millions of Californians – aligned within these natural air vents.
Continue with this developing photo essay as we demonstrate how wind shapes our world and how we can estimate wind direction and speed by looking up at the sky. We highlight some of the windiest episodes that ended the winter and continued into the spring of 2024. Conditions became particularly exciting at the end of this wet and stormy El Niño season, which threatened to complete the wettest two consecutive years in Los Angeles history. If you are looking for more detailed meteorological explanations for all this air pressure and wind mania, continue to the final weather maps near the end of this story.
The wayward wind might be a restless wind, but it opens windows for us to sense the systems and cycles that rule in our natural world, beckoning us to explore and better understand the vital scientific experiments that nature conducts every minute of every day. Because we have just swirled around the edges of such a tempestuous topic during this brief summary, you might want to check out a new publication where we blow the lid off the many aeolian mysteries found on our third rock from the sun: California Sky Watcher.