Page 1 of 1

Calculate 10-min wind average

Posted: Sun 10 Jan 2010 3:54 pm
by Vincent
Hello,

1
It looks like Cumulus calculate the 10-min wind average with the wind gust data of the Fine Offset stations (WH-1080), but that's the average
wind gust not average wind speed. I think it should be calculated with the wind speed data of the station.

2
In Cumulus help is written this about web tags: "<#wlatest> Latest wind speed reading from console ". If I set calculate 10-min wind average on, this suggests that this tag displays the actual wind speed, but this is the latest wind GUST. <#wspeed> doesn't show the actual wind speed with the 10-min option on so I thought I use wlatest, according to the help file, but this isn't working.

Re: Calculate 10-min wind average

Posted: Sun 10 Jan 2010 4:17 pm
by steve
Vincent wrote:It looks like Cumulus calculate the 10-min wind average with the wind gust data of the Fine Offset stations (WH-1080), but that's the average wind gust not average wind speed. I think it should be calculated with the wind speed data of the station.
Yes, I know, and I sort of agree with you. But when I suggested that I change it, quite some time ago, the response I got from everyone was that the current calculation seems to produce a sensible figure anyway, so I left it as it was. I suppose I could offer it as an option...
In Cumulus help is written this about web tags: "<#wlatest> Latest wind speed reading from console ". If I set calculate 10-min wind average on, this suggests that this tag displays the actual wind speed, but this is the latest wind GUST. <#wspeed> doesn't show the actual wind speed with the 10-min option on so I thought I use wlatest, according to the help file, but this isn't working.
I'm not sure I follow you. I've explained recently in another post what the web tags represent, <#wlatest> is the "latest" on the main screen, <#wgust> is the "gust" on the main screen, and <#wspeed> is "average" on the main screen.
Please remember that Cumulus has to work with different types of weather station all supplying different types of wind speed, and I have to try to make some sense of it all and display it on the same screen.

Re: Calculate 10-min wind average

Posted: Sun 10 Jan 2010 6:08 pm
by Vincent
steve wrote:
Vincent wrote:It looks like Cumulus calculate the 10-min wind average with the wind gust data of the Fine Offset stations (WH-1080), but that's the average wind gust not average wind speed. I think it should be calculated with the wind speed data of the station.
Yes, I know, and I sort of agree with you. But when I suggested that I change it, quite some time ago, the response I got from everyone was that the current calculation seems to produce a sensible figure anyway, so I left it as it was. I suppose I could offer it as an option...
Sometimes the wind gust is more useful indeed, but here in Holland is a website where all data of amateur meteorologists can be collected: http://www.hetweeractueel.nl/friesland This site doesn't support Cumulus. We are now busy to create a file, uploaded by Cumulus, with the correct web tags. The website is also used by the Royal Netherlands Meteorological Institute (KNMI) for research at the temperature in city's.

Because of standard rules it's better to use the 10-min wind average calculated on the wind speed value of the weather station. It would be great if you can make an option of this in Cumulus.
I'm not sure I follow you. I've explained recently in another post what the web tags represent, <#wlatest> is the "latest" on the main screen, <#wgust> is the "gust" on the main screen, and <#wspeed> is "average" on the main screen.
Please remember that Cumulus has to work with different types of weather station all supplying different types of wind speed, and I have to try to make some sense of it all and display it on the same screen.
Ok, that's clear, so if I set the option for 10-min wind average on, there's no web tag for the current station wind speed, because this is now the average speed? Is it possible to add a tag that displays in this case the station wind speed?

Re: Calculate 10-min wind average

Posted: Sun 10 Jan 2010 7:00 pm
by steve
Vincent wrote:Sometimes the wind gust is more useful indeed, but here in Holland is a website where all data of amateur meteorologists can be collected: http://www.hetweeractueel.nl/friesland This site doesn't support Cumulus. We are now busy to create a file, uploaded by Cumulus, with the correct web tags.
The point I'm trying to make is that the general opinion seemed to be that the result of the calculation did come out with a good figure for the 10-minute average speed, regardless of the apparently illogical way it was calculated. Let's not forget that these are very cheap weather stations and most people don't site them in standard positions, so any data that comes out of them is suspect anyway.
Ok, that's clear, so if I set the option for 10-min wind average on, there's no web tag for the current station wind speed, because this is now the average speed?
Yes, that's right.
Is it possible to add a tag that displays in this case the station wind speed?
Tricky, because of the way Cumulus is structured. The station speed is 'lost' when you select the 10-minute option. I can consider this for Cumulus 2.

Re: Calculate 10-min wind average

Posted: Mon 11 Jan 2010 3:41 pm
by Vincent
steve wrote:
Vincent wrote:Sometimes the wind gust is more useful indeed, but here in Holland is a website where all data of amateur meteorologists can be collected: http://www.hetweeractueel.nl/friesland This site doesn't support Cumulus. We are now busy to create a file, uploaded by Cumulus, with the correct web tags.
most people don't site them in standard positions, so any data that comes out of them is suspect anyway.
I have :D. As an option it would be nice, I understand why other want to left it as it is now.
Is it possible to add a tag that displays in this case the station wind speed?
Tricky, because of the way Cumulus is structured. The station speed is 'lost' when you select the 10-minute option. I can consider this for Cumulus 2.
I see, when I set this option on, the value in the logfile jan10.txt also is the average and not the current wind speed. I didn't expect it is working on that way, because the column with the wind speed shows in this case values that are calculated with the wind gust. So an option would be very nice.. :roll:

Re: Calculate 10-min wind average

Posted: Sun 17 Jan 2010 10:33 am
by Vincent
Hi Steve,

I've got an e-mail that someone posted a message here, but it isn't here any more? When I tried to open the link in that e-mail the Cumulus forum and site were not online. Probably the message is lost or did someone deleted it?

Re: Calculate 10-min wind average

Posted: Sun 17 Jan 2010 12:15 pm
by steve
Don't know, sorry. There's no sign of a message having been deleted. Maybe it was a delayed notification for an earlier post.

Re: Calculate 10-min wind average

Posted: Tue 19 Jan 2010 9:07 pm
by mcrossley
Sorry, that would have been me. I posted an observation that on reflectin was obvious so I deleted the post straight away.

I too would like to see the ability to average the wind speed though. It would smooth out the windchill graph which is a bit 'busy' with the raw values (attached).
temp.jpg
Cheers
Mark

Re: Calculate 10-min wind average

Posted: Tue 19 Jan 2010 9:53 pm
by steve
mcrossley wrote:I too would like to see the ability to average the wind speed though. It would smooth out the windchill graph which is a bit 'busy' with the raw values
Yes, your average wind speed keeps crossing the threshold for wind chill to take effect. Are you using the station value or the Cumulus 10-minute average?

Re: Calculate 10-min wind average

Posted: Tue 19 Jan 2010 10:17 pm
by mcrossley
That is the station value, to me the gust average value seems to give a higher value than the conditions would warrant. Though looking at the graph, maybe averaging the current speed would be a little low!

As you can see from the wind graph at the moment, the current value fluctuates around - which is expected - but this also means the windchill will fluctuate by the same amount (if over the threshold).
temp.jpg
Still some averaging of the current speed would be interesting to see.

Mark

Re: Calculate 10-min wind average

Posted: Tue 19 Jan 2010 11:20 pm
by steve
mcrossley wrote:Though looking at the graph, maybe averaging the current speed would be a little low!
Yes, I think this was the conclusion that was arrived at when I first added support for Fine Offset stations. While apparently illogical, it appeared that averaging what Fine Offset call the 'gust' came up with a more reasonable figure than averaging the 'speed' would do. I can have a look at how easy it would be to have that as an option...

Re: Calculate 10-min wind average

Posted: Wed 20 Jan 2010 5:31 pm
by steve
This is now an option in the latest build (904).

Re: Calculate 10-min wind average

Posted: Wed 20 Jan 2010 9:12 pm
by mcrossley
Excellant! I've only been using this software a week and already I think I'll be sticking with it (and donating :) )

Thanks Steve, I'll download the beta and update my logging PC when I get home from this hotel :(.

Mark

Re: Calculate 10-min wind average

Posted: Sun 24 Jan 2010 7:00 pm
by Vincent
steve wrote:This is now an option in the latest build (904).
Thanks, Steve!

Re: Calculate 10-min wind average

Posted: Sun 24 Jan 2010 7:05 pm
by mcrossley
I have now been running with the WH1090 with the 10 minute average 'speed' set rather than gust and it seems to be working well. I have also switched on the direction averaging at 30 mins and that is working brilliantly (with no mods to the hardware).
Check the link to my website on the sig banner below to view (though there is virtually no wind today).

Thanks again Steve.
Mark