Wind speeds seem wrong

kayjay · Post by **kayjay** » Mon 16 Nov 2009 11:56 am

Am I misunderstanding something or are the wind speed and wind speed(gust) the wrong way around? See http://www.zen33683.zen.co.uk/weather/trends.htm

I'm using La Crosse Ws2350 and the speed is always higher than the gust.

Many Thanks

Post by **steve** » Mon 16 Nov 2009 12:33 pm

The WS23xx only supplies one wind speed value, so normally you would expect the two values to be the same. But there are a few settings in Cumulus which can affect this.

In the station settings, have you got 'Calculate 10-min wind average' set or unset, and in the display settings, have you got 'plot latest gust' set or unset?

What have you you got for wind and gust multipliers in the calibration settings?

kayjay · Post by **kayjay** » Mon 16 Nov 2009 12:45 pm

Gust and speed multipliers are both set to 1.00

Calculate 10-min ave = set

Plot latest gust = unset

Thanks

Post by **steve** » Mon 16 Nov 2009 1:07 pm

kayjay wrote:Gust and speed multipliers are both set to 1.00

Calculate 10-min ave = set

Plot latest gust = unset

I can't explain it then. With those last two settings, you would expect to see the gust line slightly above the wind line, but converging occasionally (as the gust line would be showing the peak in the last 10 minutes), but your graphs just seem to fit quite well to a 3x speed multiplier being applied.

Could you let me have your cumulus.ini file, please, with your passwords/usernames removed?

kayjay · Post by **kayjay** » Mon 16 Nov 2009 1:27 pm

See attached .ini file. I copied it over from my previous installation when I swapped PC's and installed the latest version.

Thanks

Post by **steve** » Mon 16 Nov 2009 2:00 pm

The only thing I can think is that for some reason the 10-minute average calculation is going wrong. Could you try unsetting that and see what happens?

kayjay · Post by **kayjay** » Mon 16 Nov 2009 2:47 pm

10-min ave is now unset. So far I see no difference.

Post by **steve** » Mon 16 Nov 2009 2:56 pm

I've just spotted this in your cumulus.ini file:

WindComp=4

You're applying a multiplier of 4 to the wind speed using the setting that I introduced before the calibration facility.

kayjay · Post by **kayjay** » Mon 16 Nov 2009 3:23 pm

Ah!

I copied this .ini file from my previous PC so maybe it was there for some time - I don't think I ever edited it directly. I've been running it for ages but only just mounted the anemometer properly so never paid any attention to what it said. I've cleared out all old data and it looks to be showing sensible values now

.

Very well spotted
Many thanks

Cumulus Support

Wind speeds seem wrong

Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong

Re: Wind speeds seem wrong