Beaufort and the blowhards

As with fish tales and fishermen, we boaters have a tendency to exaggerate regarding the size of the wind. And why not? After all, there’s nothing so boring as an average statistic. Exaggerating wind speed, especially if you’ve been out in it on the water, makes one more of a hero and keeps a captive audience.

Now, I don’t care much about exaggerated fish tales, but this wind thing has bugged me for quite some time.

On one breezy day last fall, as I climbed up the yacht club porch stairs, one of the members hunkered down behind one of the porch columns said: “It’s really howling, huh Dave? Steady around 30, gusting to 40, I’d guess.” He shook his head and lifted the collar of his monogrammed Sou’wester jacket a bit higher. “Yup, been out in stuff like this. No fun.”

Yes, you did indeed guess, I thought. Steady at 18, I would have guessed. And maybe gusting to high 20s. Maybe. Because . . . .

Anyway, let’s give people the benefit of the doubt. Let’s give them credit for being genuine in their thoughts. Let’s give them credit for not being B.S. artists, for many people may think they really know how hard the wind is blowing, though science shows that they usually get it wrong. Researchers have known this for years, but a recent study sought to quantify just how bad humans are at figuring out the speed of wind gusts without the aid of meteorological instruments.

Even weather spotters who report storm measurements and observations to a U.S. national compendium of storm data often exaggerate winds speeds – by about one third, on average. So, what must it be with recreational boaters’ estimates?

To test the accuracy of human-generated wind-gust reports, the researchers compared storm data wind-speed entries from storm reporters who didn’t use anemometers with wind data from automated weather stations. In a study published in the “Journal of Applied Meteorology and Climatology,” the authors also used instrumental data from the Global Historical Climatology Network as a comparison for the human-reported gusts.

The researchers focused on windstorms without rain, lightning, or other phenomena that could frighten observers, accidentally inflating their estimates of the storm’s intensity. (In those cases, we’d most likely have an even more inflated story!) They also eliminated news media reports from consideration as human-observer data, because news reporters might have relied upon instrumental data from local weather stations, and of course, to the reporter, the more sensational the bigger the audience.

Even with those potential biases removed, the comparisons revealed that storm reporters overestimated the speeds of wind gusts again – on average, by about one third of the gusts’ actual speeds!

Some climate scientists even think the Beaufort Scale is flawed. As an example, the scale indicates that trees blow over at wind speeds of 58 mph and above. However, research has shown that trees can fall over at much lower speeds, in the low 40-mph range.

Many of us have heard that there is not a linear relationship between wind speed and the damage that is produced. Power actually increases proportional to the cube of the wind speed (no small point!). As the wind speed increases the power produced increases at a rapid rate. For example, the wind speed at 15 mph produces 3,375 units of power (153). When the wind speed is doubled to 30 mph then the power produced by the wind would be 27,000 units (303). Got it? In other words, a LOT more!

So, the next time you think “it’s really howling,” before saying how much and that you’ve been out there in it before, look for those two red flags flying (Gale warning: 34-47); those are supposed to represent the real numbers. Or better yet, look for an anemometer.

And if it is a real gale, maybe stay on the porch.

Safer there.

And you’ll still find plenty of blowhards ashore with whom you can share your wind stories.

Look for David Roper’s forthcoming book, “Beyond Mermaids . . . Life’s Tangles, Knots & Bends.” It’s a sequel to “Watching for Mermaids,” a three-times bestseller available on amazon.com.

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