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Strange Data anomalies after power cut

Posted: Thu 29 Dec 2011 3:44 pm
by fajja
Hello, yesterday in Scotland we got another battering, my weather station last reported a gust of 87mph at 13:40, then the power cut happened and my laptop when into Sleep mode. During this time the base station should still record all the data? However when I got home after the power came back on, i fired up Cumulus but the whole afternoon's data was missing, so I closed cumulus and edited the today file so that it would redownload all the data, which it did. However, the data shown was not as bad as my family said it was, yes they could be wrong!

Heres the confusing thing... I upload the data to weather underground, it reports the top gust for the day at about 73mph, and when i installed easyweather to double check the data it said the maximum gust was 85mph at 16:30. whereas Cumulus reports 87mph at 13:40!

Surely all 3 should show the same data? I can understand why weatherunderground wouldnt show the max gust, because the gust was not at the time of reporting? (it updates every 30mins, so if the max gust was say 15mins after the last report, it will only show the gust at the time of the data report?)

All the data is still on the base station, is there a fool proof way to check the data? or redownload yesterdays entire day from the midnight rollover so that the data is continuous rather than having it chopped to start after when the power went out?

I hope you understand and can maybe suggest a better way to redownload the data so that everything is on the same wavelength, rather than having 3 different outputs from the same data!

Thanks in advance for your help :)

Re: Strange Data anomalies after power cut

Posted: Thu 29 Dec 2011 3:53 pm
by steve
The results you get depend on whether it was live data or downloaded from the logger. Cumulus was running at 13:40, and read a gust of 87 mph, so that's the high value as far as it's concerned. When the data comes from the logger the only values available are those at the time the entry was made, so the high gust value is likely to be different.

If Cumulus was still running when your PC went to sleep, it wouldn't subsequently download the missing data automatically.

Re: Strange Data anomalies after power cut

Posted: Thu 29 Dec 2011 3:57 pm
by fajja
Ah right, so when the power was off if would only get the gust at 30min intervals? I've changed it to 5mins at the moment during the storms so hopefully wont miss more big gusts!

Re: Strange Data anomalies after power cut

Posted: Thu 29 Dec 2011 4:09 pm
by steve
Yes, that's right. The longer the logger interval, the more likely you are to miss gusts (in particular) when Cumulus isn't running.