Re: [weewx-user] Re: wind speed wrong (kph/miles)

[Thomas Keffer]

I live in the Columbia River Gorge, an extremely windy area in the summer.
About 5 years ago, I moved the wind sensor from the top of my roof to a 3
meter post in a back field. Wind speeds dropped by half.

Kestrel  makes very high quality
hand-held meters. Their model 2000

measures wind and temperature and is under $100. Mine is over 20 years old
and still functions perfectly.

-tk

On Sun, Mar 8, 2020 at 4:55 AM Stefan Pachlina  wrote:

> Hello,
>
> hmm, i will do following.
> 1) i will buy a hand-held-windmeter to check windspeed at the current
> position of my weather-sensors ... maybe you are right and the position of
> the windsensor is not perfect.
> 2) I will move my weatherstation-outsensors to the top of the roof.
> (currently its not at the top, 3m lower, but no slipstream from west, north
> and south)
>
> You should know that I see many kilometers to the mountains.
> There is nothing higher in sight (from the west) than my house. So the
> wind loves my roof :D
>
> i am just wondering why all other stations i checked have the same
> "problem".
>
> lets see :)
>
> thx for you help 
>
> Am Sonntag, 8. März 2020 02:50:12 UTC+1 schrieb Cameron D:
>>
>> Hello Stephan,
>> I am still not sure why you think your station was reading 100km/h. I
>> wonder if the following could explain the discrepancy...
>>
>> If that speed came from official weather reports, then their standard (in
>> many countries) requires that they are measured in open flat areas with the
>> anemometer 10m above ground level.  Wind speed decreases as you get closer
>> to the ground.
>>
>> Also, the presence of buildings, trees and so on, creates a much more
>> turbulent flow. The wind can have as much energy but lower measured speeds
>> are recorded since vertical components are not normally measured by home
>> instruments.
>>
>>
>> Cameron.
>>
>>
>> On Thursday, 5 March 2020 03:32:24 UTC+10, Stefan Pachlina wrote:
>>>
>>> Hello,
>>>
>>> feb 24 2020, it was a stormy day in austria ... but most weatherstations
>>> (weewx-map, wunderground-map) show windspeed like 64kph.
>>> but on this day wind speed was ~103kph
>>> i have the same problem with my weather-site.
>>> http://wetter.pachlina.net/
>>>
>>> *i configured weewx.config to see kph:*
>>> Groups
>>>   
>>>   group_speed = km_per_hour
>>>   group_speed2 = km_per_hour2
>>>   
>>>
>>> but what i see are miles and not kph.
>>> cause if i multiplicate the wind-speed with 1,61 i get the right
>>> wind-speed of 103 kph
>>>
>>> so what is to do to get the right values?
>>> is there something more to do?
>>> i read the manual again and again, but i cant find the solution to see
>>> right wind speed.
>>> all other values are ok .. like temperature in celsius.
>>>
>>> and this is what i see on many many weatherstation around austria,
>>> germany  with weewx-map, wunderground, ...
>>>
>>> h any idea?
>>> thx
>>>
>>> Stefan
>>>
>>> --
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[weewx-user] Re: wind speed wrong (kph/miles)

[Stefan Pachlina]

Hello,

hmm, i will do following.
1) i will buy a hand-held-windmeter to check windspeed at the current 
position of my weather-sensors ... maybe you are right and the position of 
the windsensor is not perfect.
2) I will move my weatherstation-outsensors to the top of the roof. 
(currently its not at the top, 3m lower, but no slipstream from west, north 
and south)

You should know that I see many kilometers to the mountains.
There is nothing higher in sight (from the west) than my house. So the wind 
loves my roof :D

i am just wondering why all other stations i checked have the same 
"problem".

lets see :)

thx for you help  

Am Sonntag, 8. März 2020 02:50:12 UTC+1 schrieb Cameron D:
>
> Hello Stephan,
> I am still not sure why you think your station was reading 100km/h. I 
> wonder if the following could explain the discrepancy...
>
> If that speed came from official weather reports, then their standard (in 
> many countries) requires that they are measured in open flat areas with the 
> anemometer 10m above ground level.  Wind speed decreases as you get closer 
> to the ground.
>
> Also, the presence of buildings, trees and so on, creates a much more 
> turbulent flow. The wind can have as much energy but lower measured speeds 
> are recorded since vertical components are not normally measured by home 
> instruments.
>
>
> Cameron.
>
>
> On Thursday, 5 March 2020 03:32:24 UTC+10, Stefan Pachlina wrote:
>>
>> Hello,
>>
>> feb 24 2020, it was a stormy day in austria ... but most weatherstations 
>> (weewx-map, wunderground-map) show windspeed like 64kph.
>> but on this day wind speed was ~103kph
>> i have the same problem with my weather-site. 
>> http://wetter.pachlina.net/
>>
>> *i configured weewx.config to see kph:*
>> Groups
>>   
>>   group_speed = km_per_hour
>>   group_speed2 = km_per_hour2
>>   
>>
>> but what i see are miles and not kph.
>> cause if i multiplicate the wind-speed with 1,61 i get the right 
>> wind-speed of 103 kph
>>
>> so what is to do to get the right values?
>> is there something more to do?
>> i read the manual again and again, but i cant find the solution to see 
>> right wind speed.
>> all other values are ok .. like temperature in celsius.
>>
>> and this is what i see on many many weatherstation around austria, 
>> germany  with weewx-map, wunderground, ...
>>
>> h any idea?
>> thx
>>
>> Stefan
>>
>>

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[weewx-user] Re: wind speed wrong (kph/miles)

[Cameron D]

Hello Stephan,
I am still not sure why you think your station was reading 100km/h. I 
wonder if the following could explain the discrepancy...

If that speed came from official weather reports, then their standard (in 
many countries) requires that they are measured in open flat areas with the 
anemometer 10m above ground level.  Wind speed decreases as you get closer 
to the ground.

Also, the presence of buildings, trees and so on, creates a much more 
turbulent flow. The wind can have as much energy but lower measured speeds 
are recorded since vertical components are not normally measured by home 
instruments.


Cameron.


On Thursday, 5 March 2020 03:32:24 UTC+10, Stefan Pachlina wrote:
>
> Hello,
>
> feb 24 2020, it was a stormy day in austria ... but most weatherstations 
> (weewx-map, wunderground-map) show windspeed like 64kph.
> but on this day wind speed was ~103kph
> i have the same problem with my weather-site. 
> http://wetter.pachlina.net/
>
> *i configured weewx.config to see kph:*
> Groups
>   
>   group_speed = km_per_hour
>   group_speed2 = km_per_hour2
>   
>
> but what i see are miles and not kph.
> cause if i multiplicate the wind-speed with 1,61 i get the right 
> wind-speed of 103 kph
>
> so what is to do to get the right values?
> is there something more to do?
> i read the manual again and again, but i cant find the solution to see 
> right wind speed.
> all other values are ok .. like temperature in celsius.
>
> and this is what i see on many many weatherstation around austria, germany 
>  with weewx-map, wunderground, ...
>
> h any idea?
> thx
>
> Stefan
>
>

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[weewx-user] Re: wind speed wrong (kph/miles)

['angry tux' via weewx-user]

Hi,

I get somewhat similar values on my WH1080 station and Weewx here in 
Germany, I always thought it was just calculated average instead of real 
(momentum) values.
But maybe you are right and they are in miles

Will be interesting what the developers say.

regards
Dieter

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