People living in Blackfeet country know about wind. With energy companies talking to the Blackfeet Tribal Council and several wind generators already at work on the Reservation, it's clear the Blackfeet have resources second to none.
But people always want to know, what's the most? And here in Montana, the question is who has the most wind? "Before we moved to Montana in 1991, my wife told me she really liked Livingston but could never live there because it was too windy," said Browning High School science instructor Don Keihn. "So we ended up living in East Glacier Park. Little did we know!"
For over three years Keihn has written Blackfeet Weather, a weekly column in the Glacier Reporter which provides forecasts, commentary, records, weekly highs and lows, precipitation amounts, drought information and maximum wind gusts, all measured at his classroom's own weather station at Browning High School and six other local NOAA weather stations reporting observations on the internet.
While the Rocky Mountain Front is well known around the world for its powerful winds, Keihn noticed that people bickered about which community has the highest wind speeds-Cut Bank, Browning or East Glacier? "I realized the answer should be evident in the 129 weekly columns I had written tracking the highest wind gusts at these locations," said the science instructor.
When he looked over the reports, he found East Glacier recorded the highest wind gusts 60 percent of the time and there were five weeks with wind gusts exceeding 80 mph. Cut Bank experienced the highest speeds 23 percent of the time, Browning 16 percent and St. Mary 1 percent, but among them only Browning had a single wind event over 80 mph. "It seemed obvious that East Glacier had the highest wind speeds of any community in Glacier County," said Keihn. "Certainly, other locations are windier, but people don't live there. For example, over 18 weeks the maximum wind gusts at Logan Pass averaged 28 mph faster than those of East Glacier."
Powerful winds have blown Burlington Northern railroad trains off the trestle over Midvale Creek four times in the past 19 years in East Glacier. The crossing at Midvale Creek is situated where the stream gully sharply narrows from a much broader confluence of two stream forks, just west of the trestle, creating a strong funnel effect that amplifies wind velocity. "This illustrates the general difficulty in measuring wind speed," said Keihn. "Wind is a complex and highly variable phenomenon that involves the movement of large air masses which are very sensitive to the topography of the land, objects on the earth's surface and other little understood influences. Mountain passes, valley mouths, gullies and gorges commonly accelerate prevailing winds. Thus, it is difficult, if not impossible, to make unambiguous comparisons between different locations with regard to wind speed."
Keihn noted, for example, during the most recent two derailings in 2002 and 2003, the maximum-recorded wind speeds in East Glacier were only 53 and 67 mph, respectively. "The wind speed was measured at the Montana Department of Transportation weather station only a mile from the trestle," he said. "Nevertheless, in the latter derailing, damaging winds were estimated by some to be in excess of 100 mph, sending 25 cars and 60 containers into the creek bottom, felling large trees, causing considerable damage to roofs and destroying at least one trailer home - much more damage than is consistent with the recorded wind speed." Consequently, Burlington Northern last year finally completed the construction of a wind deflector over the length of the Midvale Creek trestle.
Keihn wondered next which community might be the windiest in Montana. "I had always heard that Livingston was an especially windy location," he said. "I researched the NOAA weather archives for Livingston on the Internet and compared East Glacier winds to those of Livingston during those 129 weeks of weather columns written in the Glacier Reporter. East Glacier displayed the highest wind gusts 52 percent of the time with a weekly maximum wind gust averaging 51.4 mph. Livingston displayed the same average weekly maximum of 51.4 mph but no episodes exceeding 80 mph."
The two communities appeared to have similar wind characteristics, although it seemed East Glacier had slightly more frequent high velocity events than Livingston. "I still wanted more information, so I consulted the Western Regional Climate Center, both online resources and individual staff members," said Keihn. "Apparently the best information available regarding windy communities is a recent listing of all airports in the 13 western states having reporting NOAA weather stations. Generally, all airports are close to communities and have weather instruments, especially anemometers. According to this list, Livingston has the highest annual wind speed in the 11 western states of the Lower 48. Annual wind speed represents the 24-7 wind speed averaged over the whole year."
Among competing local communities, Cut Bank ranked fifth in the west and second in Montana.
"Alaska has four airports and Hawaii one that display faster annual wind speeds than Livingston," said Keihn, who noted the highest annual wind speed in the western 13 states is at the Gambell airport in Alaska at 19.1 mph, while Livingston reports 15.6 mph and Cut Bank 12.6 mph.
"I knew I needed to find a way to calculate the annual wind speed at East Glacier," said the investigating scientist.
"I contacted the Montana Department of Transportation since it operates a weather station at Two Medicine Bridge on the north side of East Glacier," said Keihn. The MDT provided three full years of wind measurements taken every six minutes, and from that he calculated average annual wind speeds for 2002-2004 at 13.6, 13.1 and 12.7 mph. The monthly pattern of wind speed for East Glacier displays remarkable consistency: August displays the lowest wind speeds with an average of 8.7 mph, but thereafter the winds accelerate steeply to a maximum of 18.3 mph in November. After November, wind speed declines steadily to the minimum in August.
"The overall average at East Glacier for this three-year period was a 13.1 mph annual wind speed, ranking it second in Montana and fifth in the western half of the U.S., putting it ahead of Cut Bank," Keihn said.
National wind maps show the western half of the U.S. is much windier than the eastern half. "Furthermore, the National Climatic Data Center maintains a long list of American communities with annual wind speeds that are consistent with those on the list of western airports," said Keihn. "Still, it's possible there are even windier communities somewhere in the West that have escaped my searches or which don't have reporting weather stations."
Keihn's conclusion, offering bragging rights to some, is that Livingston, East Glacier and Cut Bank appear to be the windiest communities in Montana, in that order. Of the 11 western states in the Lower 48, the three Montana communities rank first, fifth, and sixth, respectively.