Rain total different from Weatherflow. **solved**

[Nexus6]

Hi all,
I've got a Weatherflow Sky & Air, using a TP-Link 3020 Meteobridge. I had some rain today. The interesting is that the Weatherflow app states 4.5mm rain total, while on Meteobridge I only get 1.2mm total.

How can that difference be explained? See screenshots.


https://1drv.ms/u/s!Au1A9viajZC4gvgIh3tWrYYNGRmf4A

https://1drv.ms/u/s!Au1A9viajZC4gvgJyqpyiib-svo00g

[droiddk]

https://community.weatherflow.com/

[vortexya]

I dont think this issue is for the Weatherflow forum as the data is being reported correctly to WF.
Here is also a functioning WF kit and a new Davis Instruments Australia Meteobridge unit and am using weather34 Meteobridge template.
I also got a rain alert tonight (0.2mm) and is clearly available on the WF app/webpage, but I checked the Meteobridge live data and there was no registration at all.
I am sure these are just teething problems but are valid and need to be addressed,
Kind regards.

[Nexus6]

Hi vortexya, I have raised it in the Weatherflow forum and I also agree... I thought Meteobridge should just forward / bridge what is reported by the Weatherflow hub.. If Weatherflow reports via hub to Weatherflow server 4.5 mm, I would expect Meteobridge forwarding the same.. or am I wrong?

Cheers

[vortexya]

The issue has been raised with the correct people, I am sure due to time differences it will just take a little time
They are all great systems , interacting can cause incompatabilities.
I think the WF kit connected to meteobridge and output via the weather34 template is just superb.
Cheers

[wvdkuil]

Hi vortexya, I have raised it in the Weatherflow forum and I also agree... I thought Meteobridge should just forward / bridge what is reported by the Weatherflow hub.. If Weatherflow reports via hub to Weatherflow server 4.5 mm, I would expect Meteobridge forwarding the same.. or am I wrong?

Cheers

Maybe you are wrong.
The hub uses a TCP protocol to upload the data to the WF servers. That is end-to-end checked including retransmissions when errors occur. The SKY data including the rain is uploaded once /minute. Calculations for "todays rain", "yesterdays rain", "rain-rate" and so on are done on the WF server.

But the hub uses also once/minute an UDP protocol for the local listeners, in our case the Meteobridge .
If the receiving devices(MB) are not listening (doing other things) or there is a transmission error, that data packet is lost forever. For rain that is the rain in the last minute is lost forever.
When the MB does not receive a correct package, it will never now how much rain there was. All summaries will be slightly lower.

The https://weatherflow.github.io/SmartWeather/api/udp/v94/ docs also specify a "Local Day Rain Accumulation " value but that has a "null" value.

I tested this evening using Wireshark and a browser showing the WF-API data, MB Live data tab and WF website.
It started to rain for a short period and the UDL packets contained following values (extra decimals removed) 0.044 0.022 0.013 0.011 0.013 up to a total of 0.105 mm.
The website received and displayed the same values as in the UDP packets and all data was on the WF dashboard also.

The MB did not increase its "Rain total" with 0.1 as it should have. I suspect because of the numerous network errors I saw also passing by in Wireshark, which was only checking the WF UDP port 50222.

IMHO, it is a design error to broadcast important data without any backup possibility. The UDP packet should contain a "total last 24 hours " or "running total since last reboot" for the rain value. The rain values are just to important to get lost. Missing an UV or solar value is no big deal as the next value is as good as the previous one. They do not change that fast. And there is no "total UV today" calculation. But a lost rain-measurement every few minutes invalidates todays rain, yesterdays rain, last month rain a.s.o.

I hope to catch some more rain tonight/tomorrow and report back here,
Wim

[vortexya]

Thank you Wim, very comprehensive and interesting insight, and agreed, rainfall data is too time critical to be lost.
Looking forward very much to your further investigation.
Kind regards
Gary

[vortexya]

Thank you very much to Wim, Boris and Brian , I see the latest firmware build has a weatherflow rainfall fix
Totally awesome service !

[admin]

Rain totals should be fine now, but when we miss a ydp broadcast, rain will be missing. I will request that a running rain counter is added to the udp protocol to get around missing a single transmission.

[Nexus6]

Got some rain today and I can confirm that the fix works . Thanks folks, good work.

[vortexya]

Confirmed here as well, Accumulation and rain rate very good after latest fix,
Thank you all for such fast and courteous service.

[val33]

I have noticed what I think is still a problem.

Meteobridge seems to be recording rain rate and accumulation correctly



But, the rain rate information being passed to weather Underground does not match.




It is however passing the correct information to Home Weather Station.

Am I missing something?

[Mattk]

Probably WU's interpretation of rain rate.

[wvdkuil]

I had to wait until it would rain (or drizzle) but all OK here also. As it was night-time I did not catch the UDP packets, but there will be ample rain next week. For now the values between the VUE and the WF are comparable. i assume that for a longer period of rain the values will be even closer.

Wim