Author Topic: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)  (Read 2214 times)

0 Members and 1 Guest are viewing this topic.

Offline dschmidt_2000

  • Member
  • *
  • Posts: 44
Anyone tried to dampen the wind vane on a 5 in 1?  I'm uploading to Weather Underground using VIS standalone and my wind direction plots are 'pixellated' looking. 

Figure magnetic dampening would be friction less and quiet down my readings.

Offline nincehelser

  • Forecaster
  • *****
  • Posts: 3337
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #1 on: February 02, 2014, 07:24:44 AM »
Some people just add a bit more "tail" by tying on some yarn or ribbon.




Offline dbmet

  • Member
  • *
  • Posts: 11
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #2 on: February 03, 2014, 09:06:56 AM »
Is that a hole drilled and then the yarn tied to the wind vane? Did it help with the wind  reading?

Offline nincehelser

  • Forecaster
  • *****
  • Posts: 3337
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #3 on: February 03, 2014, 11:05:34 AM »
Yeah.  It's just a drilled hole with yarn.  Some people use light metal strands.  The key is that they aren't long enough to get tangled in the vane.

I'd be careful with the drilling (and manipulation of the vane in general) if it is old.  The last time I worked with one it was very brittle from UV exposure.

If you don't want to drill a hole, you might try making some tabs on the end of the wind vane with duck tape.  I tried that once with a damaged vane, and it seemed to work fine.

Yeah...it helps, but personally I don't bother with it.  I only see it as an issue at extremely low wind speeds where where direction is poorly defined anyway.  If you're having a direction problem at higher speeds, perhaps your siting is being adversely affected by turbulence. 

Offline dbmet

  • Member
  • *
  • Posts: 11
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #4 on: February 03, 2014, 08:56:51 PM »
Thanks. Maybe I'll try it this weekend and see what happens.

Offline jems

  • Senior Member
  • **
  • Posts: 56
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #5 on: February 04, 2014, 11:03:16 AM »
I've been seeing this issue with my new installation as well.  When there's not much wind, I can see it slowly spinning around in circles.  I thought maybe it was the placement.   I'll post some pictures later, when it's nice and sunny outside.   :)

Offline nincehelser

  • Forecaster
  • *****
  • Posts: 3337
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #6 on: February 04, 2014, 12:08:18 PM »
I've been seeing this issue with my new installation as well.  When there's not much wind, I can see it slowly spinning around in circles.  I thought maybe it was the placement.   I'll post some pictures later, when it's nice and sunny outside.   :)

At very low wind speeds, direction can be next to impossible to determine.  I'm not sure what the "official" cut-off point is, but you probably shouldn't even bother note a direction if there is little to no wind.  It's sort of meaningless data.

In manual observations when the wind speed is too low to estimate a reliable direction, you'd write down "variable".  I suppose if you tried to graph "variable", it would probably look "erratic".

Offline jems

  • Senior Member
  • **
  • Posts: 56
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #7 on: February 17, 2014, 07:25:45 PM »
I've been trying to come IP with a good way to get a somewhat accurate value.   I was thinking maybe some sort of standard deviation, but even that proved erroneous.  I think the trick will be to get a certain number of consecutive values close together within a 5 minute range.  So, if I see something like: 280,274,281,260,96,91,280,290,277,248,62,54,289,277,291,265
I know to just drop the smaller sets.

Offline nincehelser

  • Forecaster
  • *****
  • Posts: 3337
Re: Anyone tried to dampen the wind vane on a 5 in 1? (or is it already?)
« Reply #8 on: February 17, 2014, 07:51:52 PM »
I don't think wind data is normally distributed.

Also, the 5n1 only has 16 directions, so degree readings are going to multiples of 22.5 degrees.

I guess I'm not sure what you're trying to visualize, but it may be best not to "over-think" it.

There are some wind observation instructions in this link that you might find helpful.

http://www.nws.noaa.gov/om/forms/resources/SFCTraining.pdf