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rain - problem
Posted: Sat Jan 27, 2018 8:20 pm
by giordolo
Hi, what does it means?
68% of the year?
it seems random numbers. Could someone explain the algorithm?
Thanks
Re: rain - problem
Posted: Sat Jan 27, 2018 10:46 pm
by Dehatter
I THINK the intent is to show how much rain you had received by this time as a percentage of the expected rain for this time.
Percentages over 100% indicate more rain than normal, and less than 100% is less rain than normal.
Now I cannot answer why Jan and yearly averages are not the same since the same number of days has passed, but I asked that in the block forums today.
I am not 100% sure though.
Tom
Re: rain - problem
Posted: Sun Jan 28, 2018 2:45 am
by Dehatter
I think I have figured out why they are different.
% for the month is based on the average rain for that month.
% for the year is based on the average for the year.
These 2 numbers will not be the same and therefore the percentages will not be the same.
For instance, if you average 31mm for the month of Janurary, that would be 1mm per day for the month. If you average 341mm per year, that would be be ,93mm per day.
So if you have 24mm accumulated by Jan 27, that would be 73% based on monthly numbers (expected 27), but 95.6% based on numbers for the year (expected 25.11). Also, if it rained 3mm today that would be 300% based on monthly numbers (1mm/day).
I hope this helps, it's has been on my mind all day. I need a hobby....wait....
Tom
Re: rain - problem
Posted: Sun Jan 28, 2018 9:45 am
by giordolo
mmmm, complex
Try to understand: in my case it means that for the day I have received lot of rain compared to the same day on my history, but it is raining less than normal (65% more or less) always based on my history......
Re: rain - problem
Posted: Thu Feb 01, 2018 4:43 pm
by Lespius
Hello,
I have noticed the same
viewtopic.php?f=51&t=1082
I have checked with my own datas. The comparaison is done with the sum of the average daily rain month to date. It works well, at least for the monthly comparaison.
For the yearly comparaison, which should have been identical in January, i dont know how it is calculated.
Re: rain - problem
Posted: Thu Feb 01, 2018 5:57 pm
by Dehatter
They wont be identical. The total amount of rain for the year on a daily basis is different than the amount of rain for the month on a daily basis. Some months contribute more to the yearly total and some months contribute less, especially if you have a rainy season.
yearly percentage= ((rain year to date)/(# of inches expected per year/# of days per year))*100
monthly percentage= ((rain month to date)/(# of inches expected this month/# of days this month))*100
The numbers are not the same for any month.
Tom