WeeWX calculates rainRate by summing the rain seen in the last 900 seconds (15 minutes) and scales this to a per hour figure by multiplying by 3600/900. So your 21.8 mm appearing in one packet/record would have resulted in 21.8. * 4 = 87.2mm/hr; exactly what you saw. Due to the 900 second window being used the 87.2 mm/hr value would have persisted for up to 15 minutes. The 34.9 value may have been the result of when the 21.8mm value arrived, impossible to say without seeing the exact loop packet/archive record history. You can change the 900 second window to some other value, say 600 seconds (10 minutes) and WeeWX would then take the rainfall seen in the last 10 minutes and scale that figure to a per hour figure (in that case multiply by 3600/600).
This is covered in the [[RainRater]] <http://www.weewx.com/docs/usersguide.htm#%5B%5BRainRater%5D%5D>stanza in the User’s Guide. Note the Userks Guide states that 1800 seconds (30 minutes) is used by default for the window but the code actually uses 900 seconds. Must fix the documentation. Gary On Wednesday, 28 July 2021 at 22:10:21 UTC+10 wysiwyg wrote: > Hi ! > > I have a situation where I'm not sure about weewx behavior and how to deal > with it :-). > > I have made my own rain sensors: It reports rain every 2min30 and reports > 0mm when there's no rain. > Rainrate calculation is not done and not emitted by the sensor: Weewx has > to handle it. > > Now come a situation: My sensor crashed yesterday and did not reported > anything over the night (it was raining). > I rebooted it a few minutes ago, without power cycle, so I don't loose the > rain counter of the night => the sensor sent 21.8mm from the whole night in > one shot. > > I would expect that the rainrate shall not be calculated...or maybe shall > be calculate with a time span between last and previous sample (yesterday > before it crashed). > > it seems not working this way as weewx reported: > - 34.9mm/h at next report following the 21.8mm record. > - 87.2mm/h the following report 5min later. > > I assume maybe weewx consider "not rain data" = "0 mm of rain" ? > > I have a couple of questions: > - Is this behavior expected or maybe it's something that could be improved > ? > - Can I delete those rainrate sample from database ? > of course my daily rain graph is a bit weird, but I want to keep the > 21.8mm (so monthly or yearly records are ok), but I don't want to have my > yearly/alltime max rainrate using this wrong data. > > best regards, > > > > > > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/e41c69d8-6ef6-4377-a35c-04b4d41e92bbn%40googlegroups.com.
