Author Topic: WS-2000 Low Wind Readings?  (Read 296 times)

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Offline mattb31

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WS-2000 Low Wind Readings?
« on: February 18, 2022, 09:34:48 AM »
Hello Everyone.

I want to see whether this sounds like a product of placement or a product of a defective anemometer.

Placement: Weather station is mounted on a pole about 7ft above ground level in the middle of backyard. It is a neighborhood so there are other houses around. Station itself is about 25 feet away from my 25 foot roof (best I could do given backyard setup).

The wind readings are consistently about half of the surrounding stations. Local airport is about 1 mile away and reported a gust this morning of 46mph. At the same time, a station basically a short walk down the street recorded 30.4mph. Meanwhile my station recorded 12.5mph.

Is this something I should reach out to Ambient about? Is there a setting on the console that might be screwing with speeds? Or is this just a product of being in a suburban neighborhood?

My station: https://www.wunderground.com/dashboard/pws/KPAPLYMO38

Station short walk away: https://www.wunderground.com/dashboard/pws/KPAPLYMO10

Local Airport: https://w1.weather.gov/data/obhistory/KLOM.html

Thanks!

Offline DelChard

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Re: WS-2000 Low Wind Readings?
« Reply #1 on: February 18, 2022, 10:28:36 AM »
Sat waiting for Eunice to blow through.
So I had a nose around.
The station you are comparing to appears to be located in open ground under power lines, with no obstructions in the direction of the prevailing wind.
If you compare your values to this station https://www.wunderground.com/dashboard/pws/KPABLUEB24, which has similar shelter in that direction, I think you'll be less concerned.

Offline mattb31

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Re: WS-2000 Low Wind Readings?
« Reply #2 on: February 18, 2022, 10:42:30 AM »
Sat waiting for Eunice to blow through.
So I had a nose around.
The station you are comparing to appears to be located in open ground under power lines, with no obstructions in the direction of the prevailing wind.
If you compare your values to this station https://www.wunderground.com/dashboard/pws/KPABLUEB24, which has similar shelter in that direction, I think you'll be less concerned.

Thanks. Yeah, I've been doing a lot of poking around too. KPAPLYMO10 is actually in someones backyard along that street but it does back up right to that field. Just wanted to make sure such a huge discrepancy in speed so close can be the result of valley/homes in the area.

Offline Rover1822

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Re: WS-2000 Low Wind Readings?
« Reply #3 on: February 18, 2022, 11:24:31 AM »
It can make a massive difference. I have a wind turbine in my backyard, and a WS-2000 about 15 feet a way although lower. Height, wind direction , obstructions, turbulence all have a great effect on wind readings.

I got involved about 15 years ago with turbines and build a few and this current one, I was an idiot, it works but I learned a lot . However , I totally ignored the fact that trees grow, etc. I know not relative, but if you want to have a realistic wind reading from your ws-2000,  that matches readings from dedicated wind measurement  systems such as those at a nearby airport , you need that clean air, biggest thing is height , for wind higher is better. But , maybe you want to know the wind at where your sensor is , in that case you are fine. The multi-sensors of the WS-2000 makes one choose the best achievable location for all sensors, which is in actuality not possible. Best spot for wind is not the same as for rain, etc. So you compromise.

Ambient:
  WS-2000
  PM 2.5(2)
  WH31B(2)
  WH40E
  WH31P
EcoWitt:
  GW1100
  GW1000(4)
  WH31(2)
  WH57
  WH51(12),
  WH40
  WH5360B
  WN34S
  WittBoy WS90 + GW2000
  WS90 (other one) + GW1100
Personal Sites: Weather Cam

Offline gszlag

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Re: WS-2000 Low Wind Readings?
« Reply #4 on: February 18, 2022, 07:56:49 PM »
..or you use a wind multiplier guide from Cumulus/Cumulus MX to give the  equivalent albeit theoretical ,wind at 10m (33 feet).
See: https://cumuluswiki.org/a/Wind_measurement#Examples:
In your case it would increase wind speed by allmost 30%.
Ambient Weather WS-2000
Ecowitt GW1000/GW1100
Ecowitt WS68: Anemometer, UV/solar
Ecowitt WH40: Rain gauge
Ecowitt WH57 Lightning sensor
Ecowitt WH32E: Outside T & H sensor
Stratus Rain Gauge (manual)
Raspberry Pi 3B+ (WeeWX/CumulusMX)
Raspberry Pi Zero 2W (WeeWX/MQTT/Belchertown)
---
http://weather.glenns.ca (pwsdashboard - live)
http://weewx.glenns.ca
http://glenns.ca/cumulusmx2/index.htm
---
Uploading to: AWN, ecowitt.net, Weather Underground, PWSweather.com, AWEKAS, Windy.com, WOW

Offline kheller2

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Re: WS-2000 Low Wind Readings?
« Reply #5 on: February 18, 2022, 10:33:25 PM »
Or you an accept that what you are measuring really is the wind at your location.   I have 26MPH gusts today in my “backyard”. That is nothing what the airport saw!
Ambient Consoles: WS-2000, WS-1900, WS-1200, WS-2902C, WS-3000-X3, WS-0900-IP(observerIP), WS-1001-WIFI
Ambient Arrays: WH65B
Ambient Sensors: WH31E(3), WH31B(2), WH32B, WH31SM(2), WH31PGW, AQIN, WH31LA(3)
Ambient Spares: WH24B(2), WH25B.
Ecowitt: HP2551BU, GW1000B(dead), GW1100B(2), GW2000B
Ecowitt Sensors: WH51, WN34BL, WN34(2), WH31, WH41, WH40

Offline DelChard

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Re: WS-2000 Low Wind Readings?
« Reply #6 on: February 19, 2022, 05:36:20 AM »
In total agreement with accepting your reading.
However, be very wary of wind multipliers.
There are multiple formulas available on the net.
The cumulus wiki example is very simple, it is based on a power law and has no compensating factor for what is known as roughness.
A more widely used formula is
V theoretical = V measured * Log e(Ideal Height/Roughness length )/Log e(Measured Height /Roughness length )
Where roughness length is based on degree and proximity of obstruction.

Table
 Roughness Class   Roughness Length m   Landscape Type
      
0                          0.0002                   Water surface
0.5                          0.0024                   Open terrain, grass, concrete
1                          0.03                           Scattered buildings
1.5                          0.055                           8 metre obstructions within 1250 metres
2                          0.1                           8 metre obstructions within 500 metres
2.5                          0.2                           8 metre obstructions within 250 metres
3                          0.4                           Small towns
3.5                          0.8                           Cities
4                          1.6                           Large cities

The problem for most of us, our location is never ideal, more so the obstruction are not equally disposed around our anemometer(s).
In my own situation, my anemometers are placed at 3 metres, in the most open area of my property.
From the SW to SE, I have virtually no obstruction, so a roughness class of 1. This gives a multiplier of 1.26.
In contrast.
From the NE to NW, I have my own and neighbours trees (approx 10m, 30ft) within 10m. This would give a multiplier of between 1.6 and 1.9.
Between these extremes, I have varying degrees of obstruction.

There is no size fits all.
Also if you are just using a console or gateway, you only have 1 multiplier available.
As mentioned in the cumulus wiki, wind gusts don't obey the rules.

Personally, I'd stick with what you have, but by all means experiment. After all, it's your device

Offline mattb31

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Re: WS-2000 Low Wind Readings?
« Reply #7 on: February 19, 2022, 03:33:29 PM »
Or you an accept that what you are measuring really is the wind at your location.   I have 26MPH gusts today in my “backyard”. That is nothing what the airport saw!

That's kind of the conclusion I am coming to as well. It's backyard weather OBS, so the gust my station feels at 7 feet is probably realistic to what I am actually feeling outside.

My main concern about asking this was that something was wrong with the station itself. It seemed super odd to me that my readings were almost always half of the one I posted down the street. From reading a bit, it seems like that sensor array (WH24) samples wind differently than the WH65.

Ambient support suggested resetting the array, but I doubt that will change my readings. Short of buying a handheld and standing next to it to read the wind, I'll probably just accept what it's giving me.

 

anything