Rain Graph.

[Phil23]

I know I'm still stuck on Version 3107, but this may be relevant to the graphs scripts.

Data shows 121mm of rain till 9:00am on 23/03/21.

But is I pan the cursor across the rain chart I see these figures...

8:40am - 114mm
8:50am - 118mm
9:00am - 0mm
9:10am - 2.6mm

Would have expected the 9:00am graph point to show the 121mm recorded as the previous days total.

Phil.

Edit:- 9:00am also shows a rain rate of 24.2mm/h which is probably correct.

[Mapantz]

As your graph shows data in 10 minute increments, and 9am as the rollover time, it can't show data from 8:50 to 8:59.

[billy]

Would have expected the 9:00am graph point to show the 121mm recorded as the previous days total.

I expected that too, but discovered the behaviour you describe some time ago when I was creating sql queries to get my historic rainfall DrillDown - https://tillyspaws.com/vp2waw/graphs_historic.php. It doesn't seem to fit the logic of all the other intervals.

As I recall I dealt with it by using a combination of rain since midnight and rainfall today.

[philpugh]

As I recall I dealt with it by using a combination of rain since midnight and rainfall today.

This would be expected from your set up wouldn't it? You are reporting (on your website) with a day starting at 9am. Perfectly valid. Your database will allow you to access data from any date/time.

The rain from 8:50 to 8:59 should be included in the previous days totals but at the start of the 'new' day at 9:00am the rainfall total must be reset to 0.

Your days reporting from SQL should be set to reflect 9am to 9am "days" also - otherwise there will be discrepancies in graphs etc.

[billy]

I log at 5 minute intervals and my rollover is at 9 am. I guess the issue is this: The last 5' log of the day (8:55 - 9:00) behaves differently from every other log interval in that it always has zero rain, even if rain fell in that period. So I can't simply add up the the rainfall in the 5' periods of the log file and assume the total will reflect the total for the day because it will not include rain in the last log period for the day. Of course cumulus keep the correct record for the day's total. But if one wants, say, hourly rainfall for each hour of the day (as in the drill down graphs), the log is not always going to be correct for the last hour of the day. That's why I get the rainfall in the 8:55 - 9:00 period from the rain since midnight variable.

I don't know what the behaviour is for those with a midnight rollover.

[mcrossley]

I don't know what the behaviour is for those with a midnight rollover.

Its the same, the 00:00 record belongs to the new day so the daily rainfall has been reset to zero. The total rainfall counter just keeps increasing though.

The current logging system cannot deal with values for two days in a single record.

[billy]

Thanks. And I guess the difference between rainfall and say temperature in a monthly log file period is rainfall is an accumulation over the period whereas temperature is an instantaneous value at the end of the period, which in this case is clearly related to the next day

[mcrossley]

Yes, but then your rainfall for any day starts at say 10mm then drops to zero and starts climbing again.

This is a cosmetic thing on the "recent" rainfall graph that it misses the last 10 minutes (or whatever) of the day, the daily graphs where you would be comparing days are fine.