[at-l] 70 years agon yesterday

[papabear.nyc at verizon.net (Papa Bear)]

Mount Washington land wind speed record: April 12, 1934

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The Big Wind, as its known now, galloped across the summit at 231 mph, 70 years ago this afternoon. It is a record that has never been broken and one that earned Mount Washington its claim to fame, Home of the World's Worst Weather. The fledgling observatory had only been manned for two years that day and on duty, waiting for spring to erupt in the mountains, were Salvatore Pagliuca, Alex McKenzie and Wendell Stephenson, as well as two guests. 

April 10. A perfect day. Cloudless and calm. Hazy. Sun dogs at 5:30 - a refraction phenomenon of no special importance. - Log book entry by Sal Pagliuca 

Winds gust over 100 mph every month of the year. Last August, visitors made their way through an 80-plus mph wind. (LORNA COLQUHOUN) The weather observers knew that there was a high-pressure ridge on the morning of April 11 and as McKenzie wrote in his account "The Way it Was": "The large ridge of high pressure continued to build, causing a major blocking pattern over the ocean. As a result, the energy east of the Carolinas was forced to retrograde to the northwest, combining with the developing system over the Great Lakes."  Hardly did we realize as we were enjoying a fine view of the Atlantic Ocean that we were to experience during the next 48 hours one of the worst storms ever recorded in the history of any observatory. - Log book entry, Sal Pagliuca 

By afternoon, clouds and fog were rolling over the mountain and rime ice measured one foot thick at the Observatory, which was then located in the Auto Road's stagecoach office. At 4 a.m. on April 12, Stephenson heard the wind howling loud and strong, but it measured only 105 mph. He suited up and headed outside with a club to beat ice off the anemometer. He then measured the wind at 150 mph. "The pieces were coming together for a major weather event," McKenzie wrote in his book. "On this day, the ridge over the Atlantic and the storm over the eastern Great Lakes had become even stronger. More importantly, the pressure gradient between these two systems was extremely tight on the northeast portion of the low. This was causing very strong and extremely rare southeast winds." By now, everyone at the summit that day, with the exception of the five cats huddled around the coal stove, were mobilized, Pagliuca wrote, "as during a war attack." "As the day wore on, winds grew stronger and stronger," McKenzie wrote. "Frequent values of 220 mph were recorded between noon and 1:00 pm, with occasional gusts of 229 mph." Just before 1:30 p.m. that day, an enduring record was set. "Then, at 1:21 pm on April 12, 1934, the extreme value of 231 mph out of the southeast was recorded," McKenzie wrote. "This would prove to be the highest natural surface wind velocity ever officially recorded by means of an anemometer, anywhere in the world." Will they believe it? was our first thought. I felt then the full responsibility of that startling measurement. Was my timing correct? Was the method OK? Was the calibration curve right? Was the stopwatch accurate? - Log book entry, Sal Pagliuca 

While there were other strong winds recorded later that afternoon, the storm only lasted a day. It weakened as it moved to the north, leaving behind some snow and icing. In the days and weeks that followed, the heated anemometer, which had been designed specifically for Mount Washington, was tested for accuracy by the National Weather Bureau. The measurement proved valid and to this day, the 231 mph wind atop Mount Washington is the highest wind ever recorded on the face of the Earth. "As science advances, it will be a fragile record down the road," Crane said. "New instruments are being designed and it is possible that higher wind speeds will be measured. The right researcher with the right equipment will be in the right place." He added, "If it happens, hopefully it will be on Mount Washington." 

The Mount Washington wind speed record was challenged once. Seven years ago, initial readings during Typhoon Paka in Guam saw a higher wind speed, but it was later determined that the reading was not valid. 
http://www.theunionleader.com/articles_showa.html?article=35978