Changing wind conditions were the culprit, at least in part, in the grounding of the Teton Valley Hot Air Balloon Rally a couple of mornings last weekend. As Balloon Pilot Rene Lusser explained, a sudden change in wind direction or speed, AKA wind shear, is a hazard to these beautiful vehicles. Imagine that big million BTU flame being blown sideways toward the fabric of the balloon itself, not a good thing. Erring on the side of caution was the wise call on the rally when shear zones are present. The small balloon they launched on Friday morning went up then veered off to the right as it rose, and the tops of the trees were wiggling in the wind even though it was calm on the ground.
But the wind this year has been a concern before the balloon rally. We have seen some pretty gusty conditions this spring and summer, prompting Christine to ask whether this had been a windier than average June in Teton Valley.
Some research into that question used data from the Driggs-Reed Memorial Airport, nearby personal weather stations reporting on the Weather Underground network, and historical data from sources like WeatherSpark and Weatherbase web sites.
First, the difference has to be pointed out between a short-lived gust of wind and the average wind speed through the whole day. In each case, we went with the latter, the daily average, when looking for an answer. These daily average wind speeds are sometimes surprisingly low, even on a windy day, because the momentary strong wind gusts are balanced out by the moments of calm.
With that in mind, here is what WeatherSpark has to say about the average wind here:
"The windier part of the year lasts for 5.0 months, from December 11 to May 9, with average wind speeds of more than 5.8 miles per hour. The windiest day of the year is March 29, with an average hourly wind speed of 6.4 miles per hour.
"The calmer time of year lasts for 7.0 months, from May 9 to December 11. The calmest day of the year is August 4, with an average hourly wind speed of 5.3 miles per hour."
Kind of hard to believe that we are in the calmer time of year, isn’t it? But notice that the difference between the windiest day of the year and the calmest day is only 1.1 miles per hour. That means it’s always pretty much equally windy here.
I was not able to find complete data from Driggs-Reed Memorial Airport for this past month, but the first half of June there showed an average wind speed of 6 MPH, compared to the 5.7 MPH historical average for June as reported by Weatherbase. So June does not appear to be far from the average expected wind speed. The nearby Saddlehorn Ranch weather station confirmed that with a 6.1 MPH average wind speed this June.
But looking back a little bit, as for May, this year's average sustained wind speed at the airport was 7 MPH while WeatherSpark puts the long term average between 6.0 MPH and 5.6 MPH. This April, the wind averaged 8 MPH at the airport while the historical average is listed as between 6.3 and 6.0 MPH. Finally in March, the end of which is the windiest day of the year on average, we averaged 5 MPH at the airport while the long term average is 6.3 or 6.4. So by that data. March was less windy than average, April and May were windier than average, then June was right about average.
Long answer to a good question, isn’t it? But the short answer has to be to be ready for gusty wind any time of year in these parts. In the winter it may bring a blizzard, in the summer it may bring a dust storm, but wind is one thing you can always count on in Teton Valley. Go fly a kite.