Hail-induced inaccuracy

Today we experienced a very unusual intensity of hail in San Diego, with rain preceding the hail. The Tempest rain sensor was reasonably accurate during the period of rain (approx 0.2”), but went off the rails when the hail started, registering a total for the day so far at 1.31”, whereas the actual amount - including hail - is 0.38”. This appears to indicate the need to of refine the haptic sensor’s ability to discern what it is “seeing”, hopefully through software, but possibly by hardware changes.

I’m curious of their “Rain Check” feature will correct this. Would love to hear what it shows once its been validated.

not surprising… it is a rain sensor… not a precipitation sensor.

i.e. will not measure hail or snow.

Just as hail sounds different on your roof than rain, the haptic sensor should be able to distinguish between the two. The time-domain signal from a raindrop impact is quite different than a hailstone.

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actually, it supposedly can. But i don’t think it is fully implemented. They already defined a “Precipitation Type” in the api (0 = none, 1 = rain, 2 = hail).


So if the API was written to allow for distinguishing between rain and hail, why hasn’t that been implemented? Are they waiting got someone else to write a plug-in?

In case someone figures out how to implement it, the value has defined in the api. It doesn’t mean there is actual code written to generate that value. Your guess is as good as mine. Perhaps it turned out it was just a bit harder to distinguish between hard rain and soft hail.

I think it would be great if they had a value for snow. I realize it could not measure snowfall accumulation, and im fine with that, but it would be great if it knew the difference between rain, hail and snowfall.

The piezo sensor measure acoustic waves. A snowflake doesn’t make enough sound when it hits the tempest. So, unfortunately this isn’t possible.

Does anyone know whether weatherflow staff is still working on this?
I use tempest weatherflow for all kind of automations and I’m struggling with it when there is (very) heavy rain - its reported as hail, but clearly its not…

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