The day the wind blew
Almost as fascinating as the peak's peculiar weather, is the how and when of this record wind speed. This record-breaking wind speed was recorded by a small non-profit observatory atop Mount Washington's summit, the Mount Washington Observatory using a specially-designed anemometer.
Alex MacKenzie, a meteorologist at the Mount Washington Observatory, and his crew, Wendell Stephenson, Salvatore Pagliuca and two guests, Arthur Griffin and George Leslie, witnessed this record-breaking event on April 12, 1934. In MacKenzie's book, "The Way it Was," he recounts in detail his experience of documenting and living to tell the tale of that amazingly windy afternoon.
When MacKenzie showed up for work on April 10, 1934, he didn't know that a phenomenally wild storm would soon whip across the summit of Mount Washington and he would have a front-row seat to one of the most astonishing weather events in history. The following is MacKenzie's account of that record-breaking day and the days leading up to it. On Tuesday, April 10, MacKenzie, going about his usual duties at the Observatory, noticed that a weak storm system located over the Great Lakes was beginning to inch its way toward New England. In addition, another swirling mass of energy was spotted off the coast of North Carolina. More importantly, a huge ridge of high pressure was in place over eastern Canada and the northern Atlantic. The crew at the observatory was enjoying a cloudless, peaceful workday on the summit of Mt. Washington.
On Wednesday, April 11, MacKenzie noted that the large ridge of high pressure was continuing to build, creating a major blocking pattern over the ocean. As a result, the energy east of the Carolinas was forced to retrograde to the northwest, where it combined with the development system over the Great Lakes. MacKenzie, along with his colleagues, awoke to a beautiful sunrise early that day and were enjoying a spectacular view of the Atlantic Ocean . with absolutely no idea that one of the worst storms in the world was beginning to brew. By afternoon, clear skies gave way to clouds, and fog began to set in. By that evening, rime ice measuring up to one foot thick in some locations, had formed on the summit. With high pressure building more and more to the north and east and low pressure becoming stronger to the west, an abnormally tight pressure gradient was forming. Meteorologists describe a "pressure gradient" as the change in pressure over some distance (either horizontally or vertically) with respect to a point in space. At this point, the winds on the summit were beginning to grow more fierce, reaching speeds of approximately 136 mph. Although this speed is above hurricane strength, it wasn't necessary to have the staff maintain a wide-awake, round-the-clock watch just yet.
On Thursday, April 12, Stephenson awoke at 4 a.m. to a much stronger and louder wind. After a quick glance of the clock, he jumped up to check the recorder. With a little converting and some quick math, he calculated an average wind speed of only 105 mph. It was clearly less than he expected and that meant one thing - the anemometer must have been slowed by ice buildup. Stephenson suited up, grabbed a wooden club and headed into the wicked wind. The force was so violent and intense that as he opened the door, he was knocked to the ground. He managed to clear the ice off the anemometer and make it back inside. He flipped on the recorder and began timing the clicks from the telegraph sounder. After three tries, he verified that the wind now topped 150 mph.
The pieces began to fall into place . a major event was beginning.
On Thursday, April 12, the ridge over the Atlantic and the storm over the eastern Great Lakes had both become even stronger, generating very powerful and extremely rare southeast winds.
Everyone was mobilized, as if at war in the midst of an enemy attack. MacKenzie dropped all other activities and concentrated on observation. The instruments, particularly the anemometer, were watched continuously to ensure they recorded constant and accurate data of the meteorological elements at work.
As the day wore on, the wind grew stronger. Speeds of 220 mph were recorded between noon and 1 p.m., with occasional gusts recording up to 229 mph. Then at 1:21 p.m., on April 12, 1934, an incredible 231-mph surface wind was recorded coming from the southeast. This was the highest natural surface-wind velocity ever officially recorded by means of an anemometer, anywhere. Strong winds were recorded later in the afternoon but by evening the system moved north and weakened. This great storm lasted only one day.
The anemometer used to record the world record surface wind speed was a heated anemometer designed especially for Mount Washington. It was constructed in Cambridge, Mass., and tested in the wind tunnel at the Guggenheim Aeronautical Laboratory of the Massachusetts Institute of Technology (MIT) in Boston.
Of course, when a world record is broken, the instrument needs a thorough check to ensure its accuracy. The anemometer was put through numerous tests by the National Weather Bureau. After a long period of careful consideration, the historic measurement of 231 mph was confirmed to be a valid reading. History was made!
The fact that such a small observatory crew could accurately measure a wind of this magnitude, during a period of very heavy glaze icing, with the technological limits of the 30s, is a tribute to their dedication during life-threatening conditions, and their remarkable engineering and maintenance of this historical outpost.
But why was this outpost established in the first place? Why did meteorologists expect something amazing could happen atop this small peak?
The scientific explanation for the bizarre conditions atop the summit is fascinating. Mount Washington lies in the path of both the major storm tracks and air-mass routes that affect the Northeast. Scientists also believe the mountains' topography and high elevations create an acceleration effect on the wind velocity.