this brings up what to me is an interesting question .... if I'm not
mistaken the standard 'wind speed' is as measured at I believe 30' (33'?)
off the ground ... I have a weather station of sorts mounted, currently, 8'
off the ground and it is kind of back in to a pocket of sorts surrounded at
a distance of 100' - 300' by a ring of trees. The rotating tower is about
200' from it and at the edge of this ring of trees.
So .... I measured, one day ... one very windy day 39Mph. The Weather
channel etc said gusts were around 50 ... but if you do the calculations on
wind vs. height the top of the tower was seeing a minimum of 100 mph! Using
that same calculation I believe if the station had been in the clear and at
30' it probably would have read around 60 .... so what happens when there is
a legit 100 mph wind?! That means around 150 at the top of the tower. It
seems, since indeed the readings are at ~30' AND since over the 'right'
terrain that means a good 50%+ higher on a tall structure, that towers are
actually subjected to more .... so is the Rohn and other tower manufacturers
ratings based on that value at 30' knowing that the height adjusted wind
will be higher? Or it is the worst case wind - i.e. at the top of the tower
and wind instruments aren't telling you whether or not you're there?
Gary
K9RX
-----Original Message-----
From: Don W7WLL
Sent: Monday, May 15, 2017 12:06 PM
To: Towertalk
Subject: Re: [TowerTalk] Wind Speed by Location
Tnx for sharing that Gene. No numbers came up for this location, but I've
maintained a WX station and auto- recorded daily most aspects of the local
wx since 2007. At my exposed location we experience interesting wind
conditions during the year!!!!!! I've a pretty good grasp on what to expect
here. So far, everything has stayed up during even the most severe wind
condx.
If ever thinking of visiting the scenic Oregon coast, there is a site owned
by the OCRG (Oregon Coast Repeater Group) providing current wx conditions
24/7 from Rockaway Beach to Yachats on the OR coast at
http://www.ocrg.org/telemetry_feed/ocrgwx.html. All of this information is
fed to the NWS through MesoWest.
Most of the wx stations are located at ham locations. I'm the 'Yachats'
site. We also host AIS and ADS-B receiving and reporting stations.
Other interesting information is also available on the OCRG site.
I know a lot of hams have wx instruments mounted outside (some on towers,
some on roofs, etc) but few installations are designed around the NOAA/NWS
wx instrument siting standard. The siting standards for the various wx
reporting instruments such as, temp, humidity, rain, wind, etc are difficult
to meet for most ham installations, so most do what works.
Don W7WLL
-----Original Message-----
From: Gene K5GS
Sent: Monday, May 15, 2017 7:55 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Wind Speed by Location
Didn't see this in the archives, maybe of interest to the TowerTalkians.
I was poking around the Internet last night and bumped into the website
of the "Applied Technology Council": *
http://windspeed.atcouncil.org/
*Enter your address and the site returns the wind speeds for that location.
Cheers,
Gene K5GS
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