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ColdWeatherClimber
12-16-2008, 04:35 AM
So the record is 231 mph, set in 1937. That's a long time ago. It makes me wonder two things. First, has that ever been reached since, or nearly reached. Second, I am wondering how accurate that measurement was with the instruments of the time, considering whether (lol weather) that velocity has been nearly achieved since, or not... If wind speeds have not encroached on 231... say 225, with modern methods of measurement, then we have to wonder if the speed was truly 231 mph...... Not to burst anyones bubble, just wondering about that.

JimS
12-16-2008, 05:59 AM
There's a lot of information about the record floating around on this site:
http://www.mountwashington.org/about/visitor/recordwind.php

The world record has many stories and fables surrounding it, like the fact that the instrument blew away, or broke, or things like that. The truth is, it was deiced shortly before the gust hit, and worked well through the storm. The instrument rotated, and made a clicking sound during rotation that was timed to calculate the wind speed. I'm told that during the gust, the clicks were transmitted via radio to Blue Hill to be independantly verified simultaneously, but I'm not sure where I heard that.

After the event, the instrument was taken down and tested for accuracy...so for the time, it was considered very accurate.

The winds haven't come close since...

Part of that is because the observatory moved off of the southeast slope to a new home with a bit more westerly aspect in the 30s, and again in 1980 to a NW facing slope. The eastern face has the greatest funnelling effect on the winds, and the greatest elevation gain. The winds came from the southeast, and the anemometer was the first thing it hit.

The next highest winds came shortly after the Obs moved to the NW location where it now resides. A gust of 182mph slammed the new building, and observers, who had figured at the time that they would never see another record for the reasons above, were suddenly excited about the new NW winds that they may have been missing...and again...it hasn't happened since.

The idea of a 100 year storm, or a 500 year storm, or a perfect storm is tossed around the summit to explain this gust a lot. The fact that we haven't seen anything like it makes it the subject of some scrutiny, but when we get complacent, or doubty, we are often proven wrong. I'm sure it will be matched again someday...

billysinc
12-16-2008, 08:02 AM
One of the things I've also heard which may or may not be true is that the number of structures that are on the summit has probably affected the surface speeds. Kind of like the wings of an airplane. If there was nothing on top of Mt Washington except an anemometer then the air would be allowed to flow easier over the top. Having a large building with tall flat sides probably does a real good job of disrupting any laminar flow over the summit.

Bill O
12-16-2008, 08:12 AM
Except there were probably more structures around in the 1930s than today.

billysinc
12-16-2008, 12:43 PM
Maybe but then again the shape of the structures might have an impact or the way they're laid out.

ColdWeatherClimber
12-16-2008, 08:53 PM
One of the things I've also heard which may or may not be true is that the number of structures that are on the summit has probably affected the surface speeds. Kind of like the wings of an airplane. If there was nothing on top of Mt Washington except an anemometer then the air would be allowed to flow easier over the top. Having a large building with tall flat sides probably does a real good job of disrupting any laminar flow over the summit.

I agree that structures on the peak would distupt getting accurate data. Why not put the instruments on the peak, and have living and monitoring stations off to the side, or under ground?

Bill O
12-16-2008, 08:58 PM
I agree that structures on the peak would distupt getting accurate data. Why not put the instruments on the peak, and have living and monitoring stations off to the side, or under ground?

How about getting rid of everything on the summit?

Actually, the Sherman Adams building is basically built into the mountain and the observatory tower receives unobstructed winds from the majority of the compass. Except of course from the direction where the 231 came from.

Brad
12-17-2008, 05:39 AM
It is interesting the old tower on Mt Mitchell in NC is being replaced by a built-into-the-mountain structure somewhat like the Sherman Adams building. The old Mt Washington Hotel was a huge building that blocked a lot of wind, especially from the west.

Mike D
12-17-2008, 09:32 AM
It is interesting the old tower on Mt Mitchell in NC is being replaced by a built-into-the-mountain structure somewhat like the Sherman Adams building.

Really?? We went up to the top in April 2006 looking for snow. Instead we found green grass and adelgid (http://www.invasive.org/hwa/) damage. Neat mountains, and the people are so polite. Waffle House off every exit... mmmmm.

Brad
12-17-2008, 03:46 PM
I thought going to Waffle House was only legal after 11PM.

The summit was closed off when I was there a couple of months ago. But, from the ranger station near the summit you could look up and see the building. I will be getting up there in the spring and will snag some pictures.