Author Topic: CWOP wind vector  (Read 2851 times)

0 Members and 1 Guest are viewing this topic.

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
CWOP wind vector
« on: November 21, 2016, 03:19:10 PM »
CWOP is great for seeing how well my station is doing.
I am really good on everything except wind.

My station line for speed is twice as long as the analysis line, but my anemometer is up high at 30 feet where it should be.  So Im thinking it's good.

But my direction analysis is about 25 degrees west of my station line.  Does that mean it's sighted too far to the west?

I have a Vantage Pro II up there.  [ You are not allowed to view attachments ]  [ You are not allowed to view attachments ]  [ You are not allowed to view attachments ]

Offline CW2274

  • Forecaster
  • *****
  • Posts: 3764
    • Conditions @ CW2274
Re: CWOP wind vector
« Reply #1 on: November 21, 2016, 03:39:19 PM »
Grain of salt. Put it where it belongs and forget the analysis.

Offline Old Tele man

  • Singing in the rain...
  • Forecaster
  • *****
  • Posts: 1294
Re: CWOP wind vector
« Reply #2 on: November 21, 2016, 05:46:13 PM »
Here's how I found / verify "true" North:

My 4-Bears (Weather Rock) corollary:

FUNCTIONALLY, this is *how* I determine(d) "true" north for my VP2:

1) SPRING EQUINOX - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
2) SUMMER SOLSTICE - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
3) AUTUMNAL EQUINOX - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
4) WINTER SOLSTICE - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.

The "straight Line" formed by the four three(*) rock locations "points" exactly NORTH(were the moss grows) - SOUTH(where the sun shines).

Done four years ago, I "check" things every three months: "Is the shadow on rock? Yep; all's OK!" (wink,wink).



(*) the two equinox rock locations coincide midway (the equinoxes) between the two solstice extremes
« Last Edit: November 21, 2016, 05:48:23 PM by Old Tele man »
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX1 Precision Digital Barograph
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline Cutty Sark Sailor

  • WxElement panel
  • Forecaster
  • *****
  • Posts: 2933
    • Frankfort Weather - TwinHollies WeatherCenter
Re: CWOP wind vector
« Reply #3 on: November 21, 2016, 06:47:21 PM »
 [ You are not allowed to view attachments ]
That's a "vector sum" of wind speed/directions during time frame. Over time theoretically it should average 'zero' if winds were equal from all directions, equal times. You are probably getting pulses and swirls from roofline and chimney. In my case, a minimum height of 11' above my roofline minimized the "urban boundary effect" of rooflines, etc. I found mine with a helium balloon on a string.... let 'er float up until you find lower minimum disturbance for several directions. (where the buffet and swirl begins to lessen) (Mine was actually 13-15' but 11' proved much more convenient).  Research suggests 15' minimum. Over time if you're aligned to North, you vector should approach the 'analysis', but your speed value will be lower due to residual "boundary effect"...
 

Offline CW2274

  • Forecaster
  • *****
  • Posts: 3764
    • Conditions @ CW2274
Re: CWOP wind vector
« Reply #4 on: November 21, 2016, 07:06:00 PM »
[ You are not allowed to view attachments ]
That's a "vector sum" of wind speed/directions during time frame. Over time theoretically it should average 'zero' if winds were equal from all directions, equal times. You are probably getting pulses and swirls from roofline and chimney. In my case, a minimum height of 11' above my roofline minimized the "urban boundary effect" of rooflines, etc. I found mine with a helium balloon on a string.... let 'er float up until you find lower minimum disturbance for several directions. (where the buffet and swirl begins to lessen) (Mine was actually 13-15' but 11' proved much more convenient).  Research suggests 15' minimum. Over time if you're aligned to North, you vector should approach the 'analysis', but your speed value will be lower due to residual "boundary effect"...
Excellent info, but he's already 30' up. Unless his anny is around "tall-ish" structures, this is a moot point. IMHO OP, don't over think this, either your vane is pointing the right way or not. Remember, you can always use your console to realign the vane as you see fit, as I do. 
« Last Edit: November 21, 2016, 07:32:05 PM by CW2274 »

Offline sundevil01010101

  • KAZSURPR41/54/57
  • Senior Contributor
  • ****
  • Posts: 202
  • Eye on the sky...
    • Surprise AZ Weather
Re: CWOP wind vector
« Reply #5 on: November 21, 2016, 07:45:38 PM »
Here's how I found / verify "true" North:

My 4-Bears (Weather Rock) corollary:

FUNCTIONALLY, this is *how* I determine(d) "true" north for my VP2:

1) SPRING EQUINOX - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
2) SUMMER SOLSTICE - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
3) AUTUMNAL EQUINOX - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
4) WINTER SOLSTICE - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.

The "straight Line" formed by the four three(*) rock locations "points" exactly NORTH(were the moss grows) - SOUTH(where the sun shines).

Done four years ago, I "check" things every three months: "Is the shadow on rock? Yep; all's OK!" (wink,wink).

(*) the two equinox rock locations coincide midway (the equinoxes) between the two solstice extremes

A lot more functional than waiting for equionxes:

1. Use the lat/long of station site and go to  http://www.ngdc.noaa.gov/geomag-web/#declination  to determine the magnetic declination for your area (10.47 E  0.33  changing by  0.09 W per year for my station).
2. Use a smart phone compass app or a decent hand compass (no crackerjack ones if they even still have those lol) to find compass north and then correct with the conveniently supplied value.  In the case above you have to correct the station to point 011 since I rounded the above mag dec to 11 degree E.
Visit https://www.surpriseazweather.com/ !!!
Bucket List - 1,000,000 visitors  :twisted: Lol...

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #6 on: November 21, 2016, 08:05:41 PM »
[ You are not allowed to view attachments ]
That's a "vector sum" of wind speed/directions during time frame. Over time theoretically it should average 'zero' if winds were equal from all directions, equal times. You are probably getting pulses and swirls from roofline and chimney. In my case, a minimum height of 11' above my roofline minimized the "urban boundary effect" of rooflines, etc. I found mine with a helium balloon on a string.... let 'er float up until you find lower minimum disturbance for several directions. (where the buffet and swirl begins to lessen) (Mine was actually 13-15' but 11' proved much more convenient).  Research suggests 15' minimum. Over time if you're aligned to North, you vector should approach the 'analysis', but your speed value will be lower due to residual "boundary effect"...
Excellent info, but he's already 30' up. Unless his anny is around "tall-ish" structures, this is a moot point. IMHO OP, don't over think this, either your vane is pointing the right way or not. Remember, you can always use your console to realign the vane as you see fit, as I do.

I never thought about correcting with the console.

Offline Scalphunter

  • Forecaster
  • *****
  • Posts: 2314
Re: CWOP wind vector
« Reply #7 on: November 21, 2016, 08:31:18 PM »
another quick way is to go out on clear night and shoot the north star.  sure beat  suns shooting and  hv=ave to look up when sun  crosses your meridian.  exact noon  doesn't always mean it is going to be correct.

John

Offline CW2274

  • Forecaster
  • *****
  • Posts: 3764
    • Conditions @ CW2274
Re: CWOP wind vector
« Reply #8 on: November 21, 2016, 08:39:17 PM »
Here's how I found / verify "true" North:

My 4-Bears (Weather Rock) corollary:

FUNCTIONALLY, this is *how* I determine(d) "true" north for my VP2:

1) SPRING EQUINOX - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
2) SUMMER SOLSTICE - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
3) AUTUMNAL EQUINOX - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.
4) WINTER SOLSTICE - at exactly NOON, placed a rock on the ground at the TOP (end) of the shadow from the pole.

The "straight Line" formed by the four three(*) rock locations "points" exactly NORTH(were the moss grows) - SOUTH(where the sun shines).

Done four years ago, I "check" things every three months: "Is the shadow on rock? Yep; all's OK!" (wink,wink).

(*) the two equinox rock locations coincide midway (the equinoxes) between the two solstice extremes

A lot more functional than waiting for equionxes:

1. Use the lat/long of station site and go to  http://www.ngdc.noaa.gov/geomag-web/#declination  to determine the magnetic declination for your area (10.47 E  0.33  changing by  0.09 W per year for my station).
2. Use a smart phone compass app or a decent hand compass (no crackerjack ones if they even still have those lol) to find compass north and then correct with the conveniently supplied value.  In the case above you have to correct the station to point 011 since I rounded the above mag dec to 11 degree E.
Unless my headache has gotten the better of me, he needs to subtract, not add from magnetic north in your example. It should be 349 degrees for true north, not 11. I use magnetic north, not true, and add 11 degrees from true.

Offline Cutty Sark Sailor

  • WxElement panel
  • Forecaster
  • *****
  • Posts: 2933
    • Frankfort Weather - TwinHollies WeatherCenter
Re: CWOP wind vector
« Reply #9 on: November 21, 2016, 08:59:48 PM »
[ You are not allowed to view attachments ]
That's a "vector sum" of wind speed/directions during time frame. Over time theoretically it should average 'zero' if winds were equal from all directions, equal times. You are probably getting pulses and swirls from roofline and chimney. In my case, a minimum height of 11' above my roofline minimized the "urban boundary effect" of rooflines, etc. I found mine with a helium balloon on a string.... let 'er float up until you find lower minimum disturbance for several directions. (where the buffet and swirl begins to lessen) (Mine was actually 13-15' but 11' proved much more convenient).  Research suggests 15' minimum. Over time if you're aligned to North, you vector should approach the 'analysis', but your speed value will be lower due to residual "boundary effect"...
Excellent info, but he's already 30' up. Unless his anny is around "tall-ish" structures, this is a moot point. IMHO OP, don't over think this, either your vane is pointing the right way or not. Remember, you can always use your console to realign the vane as you see fit, as I do. 
His Avatar image shows his (?)Vue(?) couple of feet above chimney, his profile location image would indicate ISS slightly above roof peak. I'm NOT referring to ground level. I'm talking 11'+ above structure, ... If height above structure is as I am assuming, all the orientation of mount, console adjustments, etc, won't keep him in the ballpark of perfection. Getting it 11+ above (the chimney) will give him more 'stabile', but 'not perfect' vectors and speed. I don't know where his 'new' anemometer is mounted, since his attachment is invalid. But he appears to be in an area with similar structures, and tall trees. ... so I'll now yield to those who know better than I.
 

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #10 on: November 21, 2016, 10:10:52 PM »
Yes, need new photo.
The Vue went in for refurb.
Pro II is substituting. :lol:
It is above an unused chimney.  About 30 feet up.
I have a true north app on the phone.  I think the solar cell is pointed a bit west of due south.
I just wondered if correcting some would put the station on the analysis line.

Offline CW2274

  • Forecaster
  • *****
  • Posts: 3764
    • Conditions @ CW2274
Re: CWOP wind vector
« Reply #11 on: November 21, 2016, 10:11:17 PM »
[ You are not allowed to view attachments ]
That's a "vector sum" of wind speed/directions during time frame. Over time theoretically it should average 'zero' if winds were equal from all directions, equal times. You are probably getting pulses and swirls from roofline and chimney. In my case, a minimum height of 11' above my roofline minimized the "urban boundary effect" of rooflines, etc. I found mine with a helium balloon on a string.... let 'er float up until you find lower minimum disturbance for several directions. (where the buffet and swirl begins to lessen) (Mine was actually 13-15' but 11' proved much more convenient).  Research suggests 15' minimum. Over time if you're aligned to North, you vector should approach the 'analysis', but your speed value will be lower due to residual "boundary effect"...
Excellent info, but he's already 30' up. Unless his anny is around "tall-ish" structures, this is a moot point. IMHO OP, don't over think this, either your vane is pointing the right way or not. Remember, you can always use your console to realign the vane as you see fit, as I do. 
His Avatar image shows his (?)Vue(?) couple of feet above chimney
That's the problem, it's a Vue shown, not a VP2 anny, as stated. If he meant to say his Vue, not VP2, then I completely agree with you. Without clarification, :?:

Offline CW2274

  • Forecaster
  • *****
  • Posts: 3764
    • Conditions @ CW2274
Re: CWOP wind vector
« Reply #12 on: November 21, 2016, 10:19:29 PM »
Yes, need new photo.
The Vue went in for refurb.
Pro II is substituting. :lol:
It is above an unused chimney.  About 30 feet up.
I have a true north app on the phone.  I think the solar cell is pointed a bit west of due south.
I just wondered if correcting some would put the station on the analysis line.
Well, I'll leave my last post in, albeit late.
The house definitely can play a roll here, as I thought your VP2 was elsewhere. As I said earlier, aim and shoot, forget the stupid analysis.
Now my question is, why in the hell is your VP2 the "backup?" :?

Offline nincehelser

  • Forecaster
  • *****
  • Posts: 2340
    • nincehelser.com
Re: CWOP wind vector
« Reply #13 on: November 21, 2016, 10:23:17 PM »
2. Use a smart phone compass app...

If the app is well-written, it should have a setting for "magnetic" or "true" north.

If set to "true", it will use the phone's GPS to determine the proper declination adjustment automatically.

Offline sundevil01010101

  • KAZSURPR41/54/57
  • Senior Contributor
  • ****
  • Posts: 202
  • Eye on the sky...
    • Surprise AZ Weather
Re: CWOP wind vector
« Reply #14 on: November 21, 2016, 10:42:50 PM »

Unless my headache has gotten the better of me, he needs to subtract, not add from magnetic north in your example. It should be 349 degrees for true north, not 11. I use magnetic north, not true, and add 11 degrees from true.

You are right, I have mine right but boneheaded the correction... it should be 349 for me....

I have a medical excuse though  too lol since I have just over the weekend developed shingles... sigh...
« Last Edit: November 21, 2016, 10:47:01 PM by sundevil01010101 »
Visit https://www.surpriseazweather.com/ !!!
Bucket List - 1,000,000 visitors  :twisted: Lol...

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #15 on: November 22, 2016, 09:12:59 AM »

Now my question is, why in the hell is your VP2 the "backup?" :?
[/quote]

Hence the smiley face.  I got the Pro II a couple years ago, but the Vue was working fine.  I decided to swap out when the Vue transmitter battery flashed low.  The Pro II is NOT the backup, it's obviously the primary.
My roof is high and steep, and I shouldn't be up there.  A antenna installer guy put it up for me for a fee.
He didn't get the pointing just right.  I don't want to pay him to come back, and meanwhile I am scheming a way to more easily get up there myself, but SAFELY. 
I think the solar cell is about 15 degrees too far west. That makes the wind direction read too far east. I may wait for a period of calm and then reset from the console.  I am using the Vue console.

Offline CW2274

  • Forecaster
  • *****
  • Posts: 3764
    • Conditions @ CW2274
Re: CWOP wind vector
« Reply #16 on: November 22, 2016, 02:03:11 PM »

Now my question is, why in the hell is your VP2 the "backup?" :?


I think the solar cell is about 15 degrees too far west. That makes the wind direction read too far east.


 :?:

Anyways, just use the console. No need breaking your neck (literally) for no reason.

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #17 on: November 23, 2016, 10:19:05 PM »
I hadn't realized I could adjust from the console.
Had to wait for calm winds.  Took awhile.
Then adjusted 10 degrees west.
Waited till results showed on CWOP.  Yes, blue line moved toward red line.
Just adjusted 5 more degrees.  I can get it very close without going to the roof and risking
life and limb.
I would prefer the program just let me command, "add 15 degrees to the reported wind direction".
My windspeed vector is still much longer than analysis line, but I am up at 30 feet.

Offline Scalphunter

  • Forecaster
  • *****
  • Posts: 2314
Re: CWOP wind vector
« Reply #18 on: November 24, 2016, 01:10:19 AM »
don't worry about Gladstone's BS . he will have you chasing your tail.  He can't even get me in the right location even after sending him the  correct lat/long. I'm out in the middle of nowhere as Google maps  are not that accurate when typing in an address. Don't forget that vector is also made up of an group of stations around you that only Madis knows.

John

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #19 on: November 24, 2016, 09:43:02 AM »
Yes, I read about the secret stations... :???:

Offline Cutty Sark Sailor

  • WxElement panel
  • Forecaster
  • *****
  • Posts: 2933
    • Frankfort Weather - TwinHollies WeatherCenter
Re: CWOP wind vector
« Reply #20 on: November 24, 2016, 10:19:11 AM »
don't worry about Gladstone's BS . he will have you chasing your tail.  He can't even get me in the right location even after sending him the  correct lat/long. I'm out in the middle of nowhere as Google maps  are not that accurate when typing in an address. Don't forget that vector is also made up of an group of stations around you that only Madis knows.

John

Suggest you send an email to cwop-support@noaa.gov for any CWOP database or info changes you need made :roll:
 

Offline Scalphunter

  • Forecaster
  • *****
  • Posts: 2314
Re: CWOP wind vector
« Reply #21 on: November 25, 2016, 02:47:26 PM »
Cutty that been done. They have me correct on mesowest. In fact I sent the correct 3 times. First time
they had me  off the coast of Africa, 2nd time was 20 miles s [uth in the middle of Tanana River, and 3rd time is where I am now. There APRS Location they show is my correct location.  Check it out yourself.  DW1453 on findu.


Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #22 on: November 25, 2016, 03:27:31 PM »
You have to have the correct lat/longs in whichever software delivers the weather data to CWOP.
I found the lat/long format on Weather Link difficult to pinpoint exactly right, too much rounding off.
So I had Cumulus send it to CWOP.  When I did that, it put the map pointer right on my house.

Offline Scalphunter

  • Forecaster
  • *****
  • Posts: 2314
Re: CWOP wind vector
« Reply #23 on: November 25, 2016, 04:01:55 PM »
I use Weather Display and I well know how to plot Lat/Long.  45 years at sea between military and civilian life in   deep sea sailing merchant marine  plus bush flying..   The aprs  is correct  I can drag what they think my address is all day long and it  snaps back. Even sent  Gladstone the  correct address and lat/long  and it still out there in the Boonies. Like  my station is out in the open and  his  program says I am  either in the trees, under an eave for Dew point. This time of year DP/Humidity is up in the air  due to  all the little micro climates that form  once  we hit  below  zero.  One station I know they use is 300 feet lower  and  10 degrees colder also it is 25 miles away.

John

Offline arrowspace90

  • Forecaster
  • *****
  • Posts: 331
  • Vantage Pro II, chimney mounted, 30' elevation
Re: CWOP wind vector
« Reply #24 on: November 25, 2016, 04:16:18 PM »
Mine showed China till I got correct lat longs in, my case, Cumulus.  Not CWOP

 

anything