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    Time series rainfall doesn't add up to map totals

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    • C
      ChadTyler last edited by

      I've noticed that for both NAM and ECMWF forecasts the time series details dont always add up to the total displayed on the map for the selected duration. Does anyone know why there is a discrepancy here and if one value could be considered most accurate?

      See examples below. Map views are for either a 24 hour or 48 hour duration

      4c44b6e5-799d-4411-878c-9f8cc3648c18-image.png
      8b6f05f4-3210-4a91-bd31-fa483c26a842-image.png

      Gkikas LGPZ 1 Reply Last reply Reply Quote 0
      • Gkikas LGPZ
        Gkikas LGPZ Moderator @ChadTyler last edited by

        @ChadTyler
        For me seems OK
        c2cd91a2-595a-4a6a-9b6a-2fd3055eaa05-εικόνα.png

        There is no 48 hrs duration
        430b931f-2aac-4504-adbd-9066dbc2d087-εικόνα.png

        You must count the accumulation from model's reference time.

        1 Reply Last reply Reply Quote 1
        • C
          ChadTyler last edited by

          Hi @Gkikas-LGPZ - Thanks for responding. In most forecasts I check I do mostly see consistency as you do, but even the numbers in your time series add up to 14.0 mm, not 14.5 mm. I think you're suggesting that the model's reference time may be earlier than what is displayed in the time series, and therefore is greater as it's counting precip that is not displayed?

          The model time is 2020-03-27 12:00 Zulu time/UTC, which converted to the local region is 7:00 AM CDT (-5). I'm assuming that the time series converts to the local time zone, so it shouldn't be referenced from a time prior to the converted time series. If the time series is also in UTC it still wouldn't be referencing values off the table so long as its only summing from the reference time.

          The NAM model (North American only) does report a 48 hour duration.

          idefix37 1 Reply Last reply Reply Quote 2
          • idefix37
            idefix37 Sailor Moderator @ChadTyler last edited by idefix37

            @ChadTyler
            @Gkikas-LGPZ
            Both of you are probably right. I understand that Rain accumulation map figures are from reference time of the model run. In the Meteogram if you show UTC time (in Settings select Display all time in UTC) you see missing hours from the run start in North America. Here in Europe we are closer to UTC and there are less discrepancies. It's just an assumption, I’ve not checked everywhere.

            31B4E5C2-A2F4-475C-B6DC-1146C6DB566C.jpeg

            1 Reply Last reply Reply Quote 2
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