Welcome to the new home of the Cumulus Support forum.

Latest Cumulus release v1.9.4 (build 1099) - Nov 28 2014
Latest Cumulus MX release - v3.0.0 build 3044 7 December 2018. See the Wiki for download

Graph: Wind Speed

Discussion and questions about Cumulus weather station software version 1. This section and its subforums are the main place to get help with Cumulus. Anything which is not specific to the type of weather station goes in here; for anything specific to a type of weather station, please use the appropriate subforum. Use the 'website development' section for any questions relating to creating or running a web site for Cumulus data. Discussion of the stations themselves in these sections is fine.
Post Reply
Altocumulus
Posts: 50
Joined: Sat 18 May 2013 1:58 pm
Weather Station: Davis pro vue+
Operating System: Windows 10 Home
Location: NE Scotland

Graph: Wind Speed

Post by Altocumulus » Thu 01 Mar 2018 2:44 pm

Is there a bug in the wind speed graph?. From inspection it appears the average speed lags behind the gusts.

Yellow trace on attached graph.
Untitled-1.png
You do not have the required permissions to view the files attached to this post.

User avatar
PaulMy
Posts: 1731
Joined: Sun 28 Sep 2008 11:54 pm
Weather Station: Davis Vantage Pro 2+ w/Envoy USB
Operating System: Windows-8
Location: Komoka, ON Canada
Contact:

Re: Graph: Wind Speed

Post by PaulMy » Thu 01 Mar 2018 2:57 pm

Gusts are instantaneous while average is over a period of time so includes all the lower and higher of that period. I think the graphs look fine.

Enjoy,
Paul

User avatar
mcrossley
Posts: 5234
Joined: Thu 07 Jan 2010 9:44 pm
Weather Station: Davis VP2
Operating System: Stretch Lite rPi
Location: Wilmslow, Cheshire, UK
Contact:

Re: Graph: Wind Speed

Post by mcrossley » Thu 01 Mar 2018 2:58 pm

It will, it's an average of the previous 10 (default) minutes. Until a gust occurs it will cannot be included in the average, but it will affect it for the next 10 minutes.

Altocumulus
Posts: 50
Joined: Sat 18 May 2013 1:58 pm
Weather Station: Davis pro vue+
Operating System: Windows 10 Home
Location: NE Scotland

Re: Graph: Wind Speed

Post by Altocumulus » Thu 01 Mar 2018 3:18 pm

Thanks guys, but that's not how the Met Office analyses anemographs - or not how they used to!
A gust was analysed within a band of 10 minute averages.

User avatar
mcrossley
Posts: 5234
Joined: Thu 07 Jan 2010 9:44 pm
Weather Station: Davis VP2
Operating System: Stretch Lite rPi
Location: Wilmslow, Cheshire, UK
Contact:

Re: Graph: Wind Speed

Post by mcrossley » Thu 01 Mar 2018 3:47 pm

Maybe, but for a PWS viewing 'live' data you cannot see what the wind speed will be in future to display the average speed 'now'.
If you are analysing historic data you can take a period centred on the current time.

Looking at my data it doesn't seem to lag as much as yours. What averaging period are you using? And is Cumulus or your station calculating the average?
Capture.PNG
You do not have the required permissions to view the files attached to this post.

Altocumulus
Posts: 50
Joined: Sat 18 May 2013 1:58 pm
Weather Station: Davis pro vue+
Operating System: Windows 10 Home
Location: NE Scotland

Re: Graph: Wind Speed

Post by Altocumulus » Thu 01 Mar 2018 3:51 pm

Thanks Mark - Cumulus is doing the averaging, and at 10 minute interval.

I guess it's the difference between the old fashioned anemograph analysis, and the electronic averaging.

I'd better gloss over it !

sfws
Posts: 462
Joined: Fri 27 Jul 2012 11:29 am
Weather Station: Customised mix of Fine Offset
Operating System: Tempermental Win. 10 PC
Location: UK

Re: Graph: Wind Speed

Post by sfws » Thu 01 Mar 2018 4:19 pm

The FAQ does mention divergence from met O practice http://wiki.sandaysoft.com/a/FAQ#What_d ... tations.3F

Altocumulus
Posts: 50
Joined: Sat 18 May 2013 1:58 pm
Weather Station: Davis pro vue+
Operating System: Windows 10 Home
Location: NE Scotland

Re: Graph: Wind Speed

Post by Altocumulus » Fri 02 Mar 2018 7:44 am

sfws wrote:The FAQ does mention divergence from met O practice http://wiki.sandaysoft.com/a/FAQ#What_d ... tations.3F
Thanks....

Post Reply