Thanks. I can only think of a loosely attached or vibrating tipper bouncing on and off the post it tips onto, perhaps in gusty wind or whatever it’s attached to shaking. I see a lot of 82.29 in/hr rates which seems to be some Davis max they can come up with.
0.13” in 5 minutes is 1.56 in/hr if it was steady tipping rate, not 82.29 in/hr reported 0.09 in 5 minutes is 1.08 in/hr at steady tipping, ot the 64.00 reported Really odd. Would it be wise to define some StdQC item for this station ? On Tuesday, November 4, 2025 at 12:35:28 PM UTC-8 Tom Keffer wrote: > The VP2 has hardware generation. So, unless the user changes something, > the database will record whatever comes off the console. As for how Davis > calculates rain rate, here's what they have to say in their "Derived > Variables > <https://support.davisinstruments.com/article/igpcv664kz-app-notes-derived-variables-in-davis-weather-products>" > > document. > > RAINFALL RATE > > Parameters Used: Rain Total (actually, rain rate is a measured variable in > the sense that it is > > measured by the ISS and transmitted to the display console, whereas all > other calculated > > variables are determined by the console from data received from the ISS.) > > Formula: > > Under normal conditions, rain rate data is sent with a nominal interval of > 10 to 12 seconds. > > Every time a rain tip or click occurs, a new rain rate value is computed > (from the timer values) > > and the rate timers are reset to zero. > > Rain rate is calculated based on the time between successive tips of the > rain collector. The rain > > rate value is the highest rate since the last transmitted rain rate data > packet. (Under most > > conditions, however, a rain tip will not occur every 10 to 12 seconds.) > > If there have been no rain tips since the last rain rate data > transmission, then the rain rate based > > on the time since that last tip is indicated. This results in slowly > decaying rate values as a rain > > storm ends, instead of showing a rain rate which abruptly drops to zero. > This results in a more > > realistic representation of the actual rain event. > > If this time exceeds roughly 15 minutes, than the rain rate value is reset > to zero. This period of > > time was chosen because 15 minutes is defined by the U.S. National Weather > Service as > > intervening time upon which one rain "event" is considered separate from > another rain "event". > > This is also the shortest period of time that the Umbrella will be seen on > the display console > > after the onset of rain. > > On Tue, Nov 4, 2025 at 12:21 PM vince <[email protected]> wrote: > >> Tom - how could weewx generate bizarre rainRate values in an archive >> record when the amount of rain in an interval period looks reasonable ? >> The station is a VP2. >> >> Here's one example related to that other long thread 'Correct Old and New >> Rain Records'. >> >> sqlite3 query was: >> >> echo "SELECT interval,datetime(dateTime,'unixepoch','localtime'), >> dateTime, rain, rainRate FROM archive where dateTime<1570838400 and >> dateTime>=1570752000 ORDER BY rainRate DESC LIMIT 10;" | sqlite3 >> ~/weewx-data/archive/weewx.sdb >> >> Just the interesting archive records.... >> >> 5|2019-10-11 21:45:00|1570830300|0.0|0.0 >> 5|2019-10-11 21:50:00|1570830600|0.0|0.0 >> 5|2019-10-11 21:55:00|1570830900|0.13|82.29 <== >> 5|2019-10-11 22:00:00|1570831200|0.09|64.0 <== >> 5|2019-10-11 22:05:00|1570831500|0.0|0.07 >> 5|2019-10-11 22:10:00|1570831800|0.0|0.04 >> 5|2019-10-11 22:15:00|1570832100|0.0|0.0 >> 5|2019-10-11 22:20:00|1570832400|0.0|0.0 >> >> Total for that day was 0.23" so basically all was in that 10 minute period >> >> Other than a possibly broken/chattering tipper sensor, can you think of >> anything ? >> >> -- >> 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 visit >> https://groups.google.com/d/msgid/weewx-user/e4e40f72-528a-4962-85f9-206b4d6f1212n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/weewx-user/e4e40f72-528a-4962-85f9-206b4d6f1212n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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 visit https://groups.google.com/d/msgid/weewx-user/4fb5448e-89b8-404d-9df3-843de47b4c8en%40googlegroups.com.
