Very high rainfall amounts. How to calibrate Sky?

I would like to hear WeatherFlow comment on this issue

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I think you meant haptic, hepatic refers to the liver

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I don’t want to be a field tester. I’m not into checking everyday to see if a problem has been solved, not into seeing if there is a workaround (rain offset), I don’t want to constantly check if rainfall matches my other collectors and I could care less how many stations went online everyday.
I really think they shouldn’t have been shipped with these issues.

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Yeah, my bad, was in a hurry, but presumed people would know what I was talking about

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Maybe my Sky is just jaundiced…

I have to agree with that. It appears to be a widespread problem with the values being so high as to make the rainfall sensors basically useless.

Nevertheless, looking at the data, it appears that a simple offset will likely solve the problem and probably isn’t a hardware issue. (Or rather-an issue that requires the sensors to be replaced.) I had a similar issue with the relative humidity reading being too high which was fixed with a software adjustment for my station.

I suspect the shipping process of the devices going half way around the World from China has something to do with the problem. Also, the unique characteristics of sensor mounting method used at each station location adds additionally complexity.

Is it turning yellow?

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No, just “simply”offset a bit.

I had my first experience with unusually high rainfall last night… we had a heavy thunderstorm run through, but wind speed did not exceed 12mph. Just a lot of rain in a short period of time. My measurement was almost 5”. Station ID 1810

I agree with the subject. Since the installation of the Sky it has rained twice and I have had the differences in both directions the first time I had 5l (liter) with my normal rain gauge and 3l with the Sky. Yesterday I had 18l with the normal rain gauge and 49l with the Sky. The Sky is mounted on a 2 meter aluminum pipe on the roof.

Hello Markus

first time I see numbers in liters. Guess you’re in Europe. Do we agree when you say for ex 5l, this is to compare to what I would say 5 mm = 5 liters square meters ?

I’m not Markus but indeed 5 liter rainfall is 5 liter on a square meter ergo
1 liter = 1 dm^3

Amount 1m x 1m x 1mm

This is 10dm x 10 dm x 0,01dm = 1dm^3 = 1 liter

I need to mention this method is not used in the weatherforecasts in The Netherlands but sometimes used to visualize the amount of rainfall mosty in buckets ( a full waterbucket has about 10 liters ) so when there was or comes rainfall during a storm etc with 40 mm they say this wil be equal by splashing rain on a square meter out of 3 full buckets assuming the bucket contains 10 liters :wink:

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Hello Eric,

yes spacesnow is right 1 liter = 1mm Millimeter . In the weather forecasts in Germany mm is used.

Regards Markus

I live in an area with few rain storms (Phoenix, AZ, USA). But, we have had a couple recently, and my Sky was off by a lot. I also have a CoCoRaHS compliant manual rain gauge. On a recent event, Sky recorded about 1.8", while my good rain gauge recorded .32". The latter is consistent with official flood control district gauges in the area.

My professional meteorology research friends say that haptic doesn’t work very well. They told me that before I got the latest gauge. I hoped they were wrong, and I suspect that the Sky could do a lot better than it is doing. Who knows.

In my case, the rain droplets are usually large to very large, due to the way our convective activity behaves.

I hope a fix comes out. I hope a fix is even possible.

John, I live in Denver and similar weather when it comes to actual rain. I am seeing the discrepancy in rain measurement.

Add me to the list of users experiencing the “WAY TOO MUCH RAIN” bug. Had a heavy rain event today and the SKY registered 5.45" of rain. Nearby stations seem to be averaging less than an inch…

Hi folks. Not sure how we missed this thread but I was just searching for something else and ran across it. Apologies for that.

As you’ve noticed, the rain sensor’s calibration can be off, sometimes WAY off. The main issue is that the calibration of the haptic sensor seems to depend heavily on the local installation conditions. The length of the pole or mast, what it’s made of, what’s attached to it, what it’s attached to. The good news is we’re actively analyzing the rain data coming from your SKY units and we’re confident there is a solution: a real-time QC and auto-calibration system.

You will likely continue to see some odd rain data for a while as we work what the humans are learning back into the machine learning algorithms that keep your stations calibrated. Thanks for your patience.

For some more reading on the subject, there is another thread discussing this same topic here: https://community.tempest.earth/t/rain-gauge-reading-wrong/930

I’ve noticed that the accuracy is fairly close for low/moderate rainfall rates, but downpours throw it off. We just had a heavy rain event. My rain gauge recorded 1 inch, while the Sky reported nearly 2.8". During the event, the Sky recorded one reading of a 14+ inch/hr rainfall rate, which seems dubious.

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Yes, I too have noticed that accuracy degrades as rainfall rates increase. My light rain events generally match neighboring station observations, but heavy rain events are WAY off. Regarding installation specifics, my SKY is installed on a heavy duty steel pole that’s about 3’ tall, screwed to a brick chimney with heavy brackets. It’s about as solid of a mounting scenario that one could expect.

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My station shows we had over 8" of rain in the last 24 hours, but the highest in the area was about 3" actual #4298