Wind arrow 180 degree shift

Remarks, questions, tips and tricks regarding the Netatmo iPhone application.
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Mich@el
Posts: 3
Joined: 07 Feb 2015, 13:48
Location: Schortens, Germany

Wind arrow 180 degree shift

Post by Mich@el » 26 Feb 2016, 19:47

The wind arrow indicates the direction with a 180 degree shift the iPad/iPhone App and in the Netatmo Weatherman.

https://de.wikipedia.org/wiki/Windrichtung

bluetdi
Posts: 20
Joined: 14 Jan 2016, 09:20

Re: Wind arrow 180 degree shift

Post by bluetdi » 28 Feb 2016, 08:24

Yes. And they dont fix it since month. Weather noobs seem to program that app.

skuske
Posts: 145
Joined: 13 Dec 2014, 15:11

Re: Wind arrow 180 degree shift

Post by skuske » 01 Mar 2016, 17:15

In my netatmo app (latest version) the arrow direction is correct. The arrow's head points to the direction in which the wind blows.

Not sure why it should not be correct for you... Maybe you misunderstood where the arrow head should point to... :)
Download myatmo from the iTunes AppStore at

https://itunes.apple.com/us/app/myatmo/ ... &ls=1&mt=8

bluetdi
Posts: 20
Joined: 14 Jan 2016, 09:20

Re: Wind arrow 180 degree shift

Post by bluetdi » 02 Mar 2016, 10:30

Sorry, simply no.

"Wind direction is reported by the direction from which it originates. For example, a northerly wind blows from the north to the south. ...
A variety of instruments can be used to measure wind direction, such as the windsock and wind vane. Both of these instruments work by moving to minimize air resistance. The way a weather vane is pointed by prevailing winds indicates the direction from which the wind is blowing. The larger opening of a windsock faces the direction that the wind is blowing from; its tail, with the smaller opening, points in the direction the wind is blowing."
(https://en.wikipedia.org/wiki/Wind_direction)

That means, the wind vane in the app should point in the direction from where the wind is blowing and not in the opposite. Look at pictures from real wind vanes. In the app it were only correct if we assume it is a windsock. But that cannot be since it sits in the center of the windrose so it must be a vane.

They should fix the direction indicator in the app one way or the other.

skuske
Posts: 145
Joined: 13 Dec 2014, 15:11

Re: Wind arrow 180 degree shift

Post by skuske » 02 Mar 2016, 12:53

This is not correct if you compare the arrow with the official beaufort symbols. Anyway - it's an endless discussion, I think. If you check the weather forecasts on TV, then you'll see that the arrow's head always points to the direction to which the wind blows.

Read this from the US National Weather Service: http://www.wpc.ncep.noaa.gov/html/stationplot.shtml

"Wind is plotted in increments of 5 knots (kts), with the outer end of the symbol pointing toward the direction from which the wind is blowing. The wind speed is determined by adding up the total of flags, lines, and half-lines, each of which have the following individual values."

Image

Image

German Wikipedia: https://de.wikipedia.org/wiki/Windrichtung

Reading below the 'Wind arrow': 'Wind arrow: the wind blows from west to east..."

The question is: which part of the beaufort symbol is the arrow's head, and which one is the tail? I assume the added flags, lines and half lines indicate the tail.

Anyway - the Netatmo app shows the arrow exactly as I am used from the weather forecasts on TV.
Download myatmo from the iTunes AppStore at

https://itunes.apple.com/us/app/myatmo/ ... &ls=1&mt=8

skuske
Posts: 145
Joined: 13 Dec 2014, 15:11

Re: Wind arrow 180 degree shift

Post by skuske » 02 Mar 2016, 12:57

Also check https://www.windyty.com

Same arrow direction as Netatmo. :)
Download myatmo from the iTunes AppStore at

https://itunes.apple.com/us/app/myatmo/ ... &ls=1&mt=8

bluetdi
Posts: 20
Joined: 14 Jan 2016, 09:20

Re: Wind arrow 180 degree shift

Post by bluetdi » 02 Mar 2016, 14:08

skuske wrote:This is not correct if you compare the arrow with the official beaufort symbols. Anyway - it's an endless discussion,
...
Anyway - the Netatmo app shows the arrow exactly as I am used from the weather forecasts on TV.
It does not make a point. I dont compare it with beaufort symbols nor with TV. The Netatmo wind indicator symbols a compass rose with centered arrow, which might stand for a vane but not any kind of windsock. On these kind of windroses the arrow points in the direction, where the wind is coming from. Ask sailors.

Image

"Der eingezeichnete Radius der Segmente entspricht der Häufigkeit der zugehörigen Windrichtung (hier wiederum die Richtung aus welcher der Wind weht)."

"Auf Wetterkarten wird die Windrichtung mit Pfeilen angegeben. Die Spitze des Windpfeils zeigt die Richtung an, in die der Wind weht."
https://de.wikipedia.org/wiki/Windrichtung

The Netatmo indicator is not on a weathermap, but just an arrow on a simplified windrose.

Mich@el
Posts: 3
Joined: 07 Feb 2015, 13:48
Location: Schortens, Germany

Wind gauge arrow 180 degree shift

Post by Mich@el » 05 Mar 2016, 15:23

bluetdi wrote:Yes. And they dont fix it since month. Weather noobs seem to program that app.
Thank You!

I worked for ten years with professional wind gauges onboard of several ships; so this kind of wind direction presentation is simply annoying me.

I had a similar amateur based discussion on facebook, being confronted with the same wrong argumentations concerning a

weather (wind) map --> http://www.gerd-pfeffer.de/zirk_wind.html#Windpfeil

and a wind gauge --> http://www.gerd-pfeffer.de/zirk_wind.html#Windrichtung.

The Netatmo-display is acting as a wind gauge; if you put arrows on a wheather map the have to shift 180 degrees.

If "the experts" ever had attended a weather forecast education (maybe just the starting lesson) this discussion would´t take place.

Youngster
Posts: 3
Joined: 16 May 2019, 20:20

Re: Wind arrow 180 degree shift

Post by Youngster » 16 May 2019, 20:29

Wow. Its three years later and they still have not fixed this stupid mistake! I'm a sailor too. And a pilot. And a hang glider pilot. The wind has been a big part of almost my whole long life. I have never seen anything so bassakwards last so long.

Youngster
Posts: 3
Joined: 16 May 2019, 20:20

Re: Wind arrow 180 degree shift

Post by Youngster » 17 May 2019, 02:04

After that last post, I went back and looked at some of my wind instrument graphic displays. Most of then convey wind direction displays by means of a small triangle the base of which sits on the ring of the compass rose and the point of which points towards the middle. Others have a long, skinny isosceles triangle the base of which sits in the middle of the rose and the point of which points to the edge. None of them have an arrow that goes from one side of the rose to the other. I still maintain that, if they did, the pointer should be pointing at the direction the wind is coming from and not where it is going too.

Let me put it another way. If you ask an average person to point out the wind direction with their finger they will point in the direction the wind is coming from and not where it is going. With all mechanical wind vanes and airport tetrahedrons, the pointy part connotes the direction the wind is coming FROM.

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