Tag Archives: storm reports

Your wind speed estimate is probably wrong

And the Beaufort wind force scale is flawed, says storm data researcher

As an avid kite flier, I’m often out in windy conditions. More than once, on a particularly windy day, I’ve guessed at the wind speed, only to be surprised when a handheld anemometer shows a speed as much as 10 mph lower than I guessed. It’s easy to think the wind is blowing stronger than it is. And a recent scientific study proves that.

“Storm reporters overestimated the speeds of wind gusts—on average, by about one third of the gusts’ actual speeds.”

The resulting paper, “Quantitative Assessment of Human Wind Speed Overestimation,” appears in the April, 2016 issue of the Journal of Applied Meteorology and Climatology (JAMC). Its authors report that “storm reporters overestimated the speeds of wind gusts—on average, by about one third of the gusts’ actual speeds,” according to a report on the study in Eos . (Members of the American Meteorology Society may view the full text of the original, JAMC article.)

I learned in SKYWARN storm spotter training that if I don’t have an anemometer, I can estimate wind speeds based on what I see the wind doing, using the Beaufort wind scale as a reference. Supposedly, an estimate based on whether the wind is (for example) causing large tree branches to move (32 to 38 mph, according to the Beaufort scale) is more reliable than an estimate based on how the wind feels against my body.

That might be true, but Beaufort-based estimates are still unreliable, because the Beaufort scale is flawed, study lead author Paul Miller told Eos.

What’s a SKYWARN storm spotter to do? I’ve heard a National Weather Service (NWS) warning coordination meteorologist say many times that damage reports are much more valuable to NWS weather forecast offices than are wind speed estimates. Now that I know my wind speed estimates — even those based on the Beaufort scale — are probably wrong, here’s what I’ll send NWS instead; a detailed description of damage I see the wind doing.

I encourage my fellow storm spotters to likewise report wind damage, rather than estimated wind speeds.