Odd 'spikes' in temperature, rainfall and wind speed ?

[adrian5750]

HI Folks
Been seeing some odd figures recently with my cheapie Watson weather station - today at about 12 noon Cumulus logged 4500 incles of rain (!!) at the same time as the outdoor temperature plummeted to -41c and 375 inches of rain was recorded. On the 25th October the system thinks it logged and average wind speed of 114 mph.

Does the team think that this represents the start of the end for this Weather station - it's a bit tiresome having to keep an eye on the beast and go round 'correcting' the data - sort of makes a mockery of the 'automatic' recording...

I'm not pointing the finger at Cumulus (having looked inside the Watson kit and seen the build quality of the kit <g>) - what's the consensus as to the 'next model up' in the personal weather station stakes - and would you expect similar funnies with a more expensive set-up ?

Thanks
Adrian www.ambquality.co.uk/weather/index.htm

[steve]

If it's been OK and is now playing up, changing the batteries might help. If you still get spikes (and these stations are prone to it), the EWtempdiff setting in cumulus.ini can help (see the cumulus.ini section in the wiki). The 1.9.1 beta builds have similar settings for other parameters.

Regarding stepping up, for current models supported by Cumulus, the La Crosse stations are next, price-wise, but they seem to be no better than the Fine Offsets. So you're really looking at a Davis. I'm going to be adding support for the Oregon Scientific WMR100 and WMR200 shortly, and assuming that works, they might also be worth considering. But I don't really know how good they are.

[wd40]

This page offers a good comparison between models and might help you have an idea what is out there.

http://ambientweather.wikispaces.com/We ... ison+Guide

[adrian5750]

HI Steve
Thanks for the reply.
I'm intrigued by your comment 'these stations are prone to spikes'

Has anybody ever done any research to find out what's going on here - are we talking actual misreading of analogue data -
or (perhaps more likely) a corruption of the data either in transit from the sensor to the base unit or from the base to the PC?

Interesting comparison site - thanks WD40.
Shame there's no rating for 'produces garbage data' <g>

Steve - is it worth me trying the latest beta, if it has built-in 'sanity-checks' on the data?

Thing is - as soon as you put up an online weather station, you end up feeling responsible for the data <g> -
there's a couple of folks out there who keep an eye on my webpages and are quick to let me know if they stop updating.
Even though it did blow a gale & pour with rain last night in West Cork, it wasn't as extreme as the data says!

Thanks again
Adrian

[steve]

Has anybody ever done any research to find out what's going on here - are we talking actual misreading of analogue data -or (perhaps more likely) a corruption of the data either in transit from the sensor to the base unit or from the base to the PC?

Gina has done (and is still doing) lots of work on this, with her own software. See this thread, for example: https://cumulus.hosiene.co.uk/viewtopic.php?f=13&t=3425

Steve - is it worth me trying the latest beta, if it has built-in 'sanity-checks' on the data?

The beta doesn't have any more sanity checks than the stable release (which has lots anyway). But it does have the configurable "max difference" settings, which with careful tweaking should help to reduce the odd readings. Bear in mind that it is a beta, and has lots of fundamental changes from the stable version.