Calm Winds on the Summit

2014-04-19 16:29:52.000 – Samuel Hewitt,  Summit Intern

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The summit of Mount Washington is well known for its weather extremes, especially its winds. The winds the observers experience on a daily basis can sometimes be hard to imagine, unless of course you have had the opportunity to experience them yourself. The average wind speed at any given point during the year is 35 mph, the highest average wind speed of any recording station in the continental United States. During the winter months, the summit sees 100 mph winds on one out of every five days and hurricane force winds (74+mph) every other day. Statistically, the summit experiences its highest average wind speeds during the month of January, however 130+ mph winds have occurred during every month of the year.

While writing this, I am reminded that the former world record gust of 231 mph happened during this month nearly 80 years ago. Personally, 120 mph winds are my limit when it comes to walking around on the Observatory’s observation deck or de-icing the pitot tube anemometer. I can’t even imagine what it would be like to do those same things in 230 mph winds. I mean think about it, in order for a tornado to be given an EF-5 rating (the highest rating on the Enhanced Fujita Scale), it must have winds at some point during its lifespan that exceed 200 mph. And we have all seen what an EF-5 tornado can do to a building (Greensburg, KS 2007, Joplin, MO 2011, Moore, OK 2013). But, I guess that’s why the summit is the home to some of the world’s worst weather!

I am often asked what the lowest recorded wind speed is on the summit and many are surprised when I answer ‘0 mph’. Several times per year actually, mainly during the summer months while under the influence of a very strong area of high pressure, the winds on the summit will become light and variable at times. I have been interning for the Observatory since September of last year and have only seen calm winds once or twice. One of those occurrences was this past Thursday. It was very strange, to say the least, to be outside on the observation deck during those few minutes. As an avid lover of extreme weather, I would much rather be on the deck in 100 mph winds!

Samuel Hewitt,  Summit Intern