I suppose we should have been forewarned. After all the forecast included “winds that will make small objects into projectiles.” And did it ever! The wind roared through the spruces, and made the roof crack and pop all night. The wind chimes sounded like someone was furiously shaking them; it was a restless sleep. The next morning, I saw damage from every window: the bird feeder was torn up; Christmas ornaments were strewn all over the yard. Trash cans from who knows where lay in the street and the neighbor’s house had a huge tree lying on its roof. We must have seen fifty fences blown down as we went about our day. It was later reported that $2,000,000 damage was caused by this particular wind. Which got me to wondering…what the heck are these winds called “Chinooks” and why are they?
Scientifically, these winds are called katabatic winds. They blow all over the world where there are mountains. In the Rocky Mountains, these katabatic winds are called Chinooks, named after an Indian word meaning “snow eater.” This type of wind is first created in the Pacific where it gathers moisture and then climbs the western side of the Rockies, drops snow and cold on that side of the range. Once it crests the mountains, it has no more moisture and the wind zooms downward descending the eastern side of the mountains rapidly and increasing the temperature. Often during a Chinook, line of lenticular (lens shaped) clouds sits on top of the mountains while the hot wind comes down the mountain. These winds have been known to raise temperatures 50+ degrees in just a few minutes. With these particular Chinooks, we had record snowfalls and threat of avalanches on the Western slope followed by winds up to 111 mph and mild temperatures on the Eastern slope. At DIA, the temperature was 34 degrees on December 27, 58 degrees on December 29 and up to 63 degrees on January 2!
The katabatic winds in the European Alps are called Foehn ; Andes, the Puelche; Argentina, the Zonda and Pampero; India ,the Bhoot; Hawaii, the Kona; central Europe, the Mistral and Bora; Japan, Middle East, the Sharav; and many other names in other parts of the world. And of course, let’s not forget the Santa Ana in California.
Now this is all very interesting, but you are wondering, dear gardener, just what this has to do with the garden. Katabatic winds can wreak havoc in the garden and not just by blowing trees on your house.
• Soil moisture is lost, and the soil can blow away.
• Many trees, shrubs, and plants cannot survive the rapid temperature fluctuations; white birch does not thrive very well here because of these winds.
• Trees may wake up and begin to photosynthesize, losing moisture and dehydrating.
• The warm temperatures will sometimes trigger early sprouting. Those sprouts will then be killed in the next freeze.
• It can melt valuable snow pack which is a water source for our gardens later in the season.
• Chinooks can cause something called “Red Belt”, an area of dead or damaged trees and vegetation caused by the rapid dry out.
• Wood may split due to extreme dryness.
• It can cause avalanches by making large areas of snow unstable.
• The Chinook can create a perfect fire hazard because it dries so severely and the high winds spread fires rapidly.
• These winds can even cause wire fences to become electrified due to strong positive electrical charges. Cattle have been electrocuted in this way!
If that isn’t enough, consider how these winds affect people both psychologically and physically. Scientific journals have reported that highly strung people may begin to shake or fidget, susceptible people may get headaches, migraines, or suffer nervous disorders, while many people fell “better” others report increase feelings of depression. It has been known to cause strange attitudes and reactions in animals and people in the affected areas too. The University of Milan performed a study and their data suggested that the effects of warm katabatic winds in the Po Valley (Italy) can indeed be detected in the increase of car accidents. And this is more than just high profile vehicles being blown off the road.
I don’t know about you, dear gardener, but all I can say to this is “Yikes.” And as there is nothing to be done to stop them, the next time a Chinook is forecast,(and there will be many more this winter) I plan to get a good stiff drink, stay off the highways, stay away from wire fences and watch for unusually strange behavior in my husband.
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