“Not inordinately fond of winter, the 4 ½ feet
of snow that fell upon the Valley during
the month of April depressed me at first.”
P. Thomas (Contributor)
Yosemite Sentinel, May 5, 1967
Published by the Yosemite Park and Curry Company
“Enjoy the little things, for one day you
may look back and see they were the big things.”
Robert Brault, American Writer
I don’t know if P. Thomas, a resident of Yosemite National Park in 1967 and quoted above, ever came to appreciate the significance of his/her experience during April of that year. I can only ask you, “When was the last time you saw 4 ½ feet of snow in Yosemite Valley in April?” If you are younger than 55, then “never” would be the correct response.
In fact, if I claimed that 80 inches of snow ever fell during one month in Yosemite Valley, you might think I was spinning a yarn in much the same way as seafaring merchants of long ago. If so, it would be unlikely that you would demonstrate any appreciation for the event. It's true that listeners of the seamen’s tales had only their word to go on as they spoke of things people had never witnessed before. They shared tales of gigantic rogue waves that came out of nowhere and lifted their boats 50 to 80 feet above the ocean surface. At least, the ones who survived such waves could speak about them.
Even scientists lacked appreciation for this ocean behavior, tending to dismiss these stories, claiming them to be the result of sailors’ imaginations as they filled their time on long journeys with story-telling. Additionally, disbelief in these unusual ocean occurrences rested on the scientific understanding that “according to the basic physics of ocean waves, the conditions that would produce a 100-footer were so far beyond rare as to virtually never happen.” -- The Week, Online Magazine: 1/8/2015
Yet, tales continued of short-lived, monster waves with steep walls and deep troughs, capable of mangling even the most seaworthy vessel if it encountered the misfortune of being broadsided by them. Scientists maintained a disregard for these first-hand reports.
On January 1, 1995, however, all of that changed. The Draupner gas-drilling platform, constructed in 1984 and arising out of the North Sea about 99 miles off the coast of Norway, recorded a biggie! The rig, designed to bring natural gas to European countries, also came heavily equipped with wave-sensitive monitoring devices accurate to within one inch. At about 3:20 pm, the platform’s laser-rangefinder device recorded a 66-foot (20 m) monster wave that shook the oil rig at 45 miles an hour.
Generally speaking, a freakish wave like this tends to “occur when a larger wave appears in a group of smaller waves. In some circumstances, these can lead to an exaggerated 'Spike Wave', like the one that hit the Draupner platform.” (See Video: Recreating Spike Waves in the Lab) The size of the Draupner “Spike Wave” can be seen in the graph below (Photo courtesy of ResearchGate.net and EB Djatmiko; Measured in meters).
Like the development of rogue waves, weather patterns also exhibit this cyclic nesting of energy to produce once-in-a-lifetime events that may not be fully appreciated when they occur. They reflect multiple interdependent forces that act upon each other to accumulate patterns that have a bearing far into the future, based on occurrences far in the past.
For example, the US Forest Service “Climate Change Resource Center” webpage notes the ‘millennial, century-scale, interannual or decadal cycles’ that impact the prevailing weather. It continues by saying that “Cycles at each scale are caused by a variety of physical mechanisms. Climate over any given period is an expression of all of these nested mechanisms and cycles operating together.” Consequently, the weather exhibited today has been influenced by the forces that produced weather pattens of long ago. Wow! Each cyclic wave of movement of the jet stream and its swath across continents, pushing and shoving, impacts the next day’s weather and that of many years to follow. Likewise, last years’ flow of warm ocean currents affects this year’s temperature on the earth.
The cumulative weather pattern that passed over Yosemite Valley during April 1967 really did produce a monthly total of 80 inches (2 m) of snow. It could be considered one of those “freak” or spike waves whose significance may not be recognized at the time. Unexpected and unpredicted, the multiple storms that dumped record amounts of rain and snow over much of California far exceeded the average precipitation amount for a typical April.
For comparison purposes, January, the heaviest snow month in Yosemite, averages 17 inches (.42 m) of snow. April, on the other hand, averages one inch (2.54 cm). So, getting 80 inches of snow in April could be considered a once-in-a-lifetime event. Oh, P. Thomas, you felt depressed at first, but did you ever come to see the magnitude of that snowfall and the significance of what you witnessed? The California High Water Report called it a once-in-20,000-year event! That report added that "By the end of April, the statewide water content of the snowpack was 225 percent of normal. The year's snow accumulation was comparable to, and in some areas greater than, that experienced in the big snow years of 1938, 1952, and 1958.” Yes, that was a “Draupner Wave” in terms of magnitude and intensity—a once-in-a-lifetime occurrence!
The Average Snowfall Chart for April (shown below), including 1967, looks amazingly similar to the Draupner wave that spiked up and exceeded any other wave recorded. That’s historic!
No one can say how many years this “spike-wave” of record snow was in the making and how many weather patterns nested together join at just the right time, but it really did happen! I am not telling some story because I have a need to pass my time conjuring up a fairy tale. Not only does P. Thomas’ words confirm the record amount of snow in April 1967, but the chart below (from Climatological Data: California) provides further evidence.
With weather patterns as they are today, any snow that falls in Yosemite Valley should not be considered a small thing and of little significance. One day we may all look back and think that even one inch of snow in Yosemite Valley in April is a “big thing.” As for me, instead of finding that depressing, I will always appreciate whatever amount of snow the weather cycles deliver while passing over Yosemite.
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