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Longest Dry Run curiosity

Discussion and questions about Cumulus weather station software version 1. This section is the main place to get help with Cumulus 1 software developed by Steve Loft that ceased development in November 2014.
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patchpeek
Posts: 3
Joined: Sat 23 Jul 2011 9:52 am
Weather Station: Maplin N96GY
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Location: England

Longest Dry Run curiosity

Post by patchpeek »

My Cumulus "Longest Dry Period" ended at 31 days, when we had 0.6mm on the 21st July. However whilst listening to a BBC weather man on Radio 4 talk about some areas experiencing 45+ days continuious days of no rain, he said that rain less than 1mm does not officially count! I was very suprised. Did i hear that right ? I would be on 46 days if the brief shower was excluded....

This seems to suggest,if true, that the Cumulus Software defintion of "Dry Run" or the default "RainDayThreshold" might not be quite right perhaps.

This is not a complaint and I don't have an issue; it works as I expect and want. Perhaps you are aware or not, either way, I just thought I would throw this up here out of curiosity.

Best Wishes.

pp
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steve
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Re: Longest Dry Run curiosity

Post by steve »

I'm pretty sure that the Cumulus default of 0.2mm corresponds to the official definition of a dry day as defined by the Met Office and/or the WMO, or at least it did at the time I wrote the code. See this page, for example: https://www.metoffice.gov.uk/climatecha ... daily.html

Perhaps the definition has changed. But 1mm is quite a lot of rain, I don't think I would regard that as a dry day myself.
Steve
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dazza1223
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Re: Longest Dry Run curiosity

Post by dazza1223 »

note just me then have the same thing min say 12 off may last time we hade rain but it saying Days Since Last Dry Day 44 Days but it ment to be over 60 days now
Have fun and keep learning

dazza :D

https://www.davisworthing.co.uk

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steve
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Re: Longest Dry Run curiosity

Post by steve »

dazza1223 wrote:note just me then have the same thing min say 12 off may last time we hade rain but it saying Days Since Last Dry Day 44 Days but it ment to be over 60 days now
This is nothing whatsoever to do with that.
Steve
RayProudfoot
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Re: Longest Dry Run curiosity

Post by RayProudfoot »

steve wrote:But 1mm is quite a lot of rain, I don't think I would regard that as a dry day myself.
I agree. That's 0.04" in old money. I set the trigger at 0.01" as I can get quite a few days with dew recorded.
Cheers,
Ray, Cheshire.

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dazza1223
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Re: Longest Dry Run curiosity

Post by dazza1223 »

o sorry my bad i just re read it sorry steve
Have fun and keep learning

dazza :D

https://www.davisworthing.co.uk

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