83886.07 inches of rain -- Solved!

Linn · January 10, 2021, 9:19pm

I’m posting this in case anyone else runs into this problem, to save them some time. (I know that @rraisley has also had this happen to him).

Early this summer I installed my own PWS, an Acurite 5-in-1. Worked just fine with Weather Underground until the middle of August, where for a couple of weeks it recorded 83886.07 inches of rain per day, and then automagically (that’s a technical term for IT folks) fixed itself. It started again on Dec. 7. I went out of town for 3 weeks for Christmas thinking it might automagically fix itself again, but no such luck. The daily recording on WeatherUnderground always looked ok, but the weekly and monthly were messed up, and that is what Rachio was picking up. Started looking at it closer, and I noticed that on days when it recorded precipitation, the total accumulated amount was correct at 11:54pm, but at 11:59pm it showed 0. Checked the Acurite device’s time, and discovered that it was now one minute faster than my phone was showing. Set it back one minute to match my phone time, and all is well with WeatherUnderground again. My guess is that the Acurite (unlike it’s name would make you think) runs ever so slightly fast, and the time got out of sync. Since it is hooked up to the internet, I would have thought it would have picked up the time from there, but silly me!!!

Good news is that it appears to be fixed.

rraisley · January 10, 2021, 10:08pm

Is it really solved, though? If it gets the 83k figure /somewhere/, wouldn’t that just change when it gets it? It’s not like it adds the total in from the next/previous day.

I certainly /hope/ it’s fixed, and if it is, this may be the way to do it. We’ll, uh, you’ll see.

Gene · January 11, 2021, 1:53am

Intersting, I’ve also had the issue with RTC running out of sync with real wold on the acurite display, difference is my display did not send data to WU, thus wrong time was more of an inconvinuence than anything. I ended up having to send mine for RMA rapair back to Acuririte, but it took a few weeks for them to get it back to me. Alas they opt for repairing fialed unitrs, rather than more expedited replacement policy.

Point of my post is that time will likely go out of sync again. Keep monitoring and logging the time difference. You will likely have to send the display back to AcuRite before it is repaired as it should have been to beging with.

Linn · January 11, 2021, 6:06pm

Well, the symptoms are not 100% consistent. When I had the problem last October, the 83866.07 number showed up at the 11:59pm time. And the day we switched to regular time instead of Daylight Savings, the symptoms went away.

When the problem started on Dec. 7, the 11:59pm time always shows 0 for the accumulated precipitation. My guess is that internally the programs use times right down to the seconds and then just displays the minutes. And when that last time of the day is off what the WU program is expecting, it goes to the wrong place to finish the calculations for the daily precip amount. My guess is that someone didn’t program for the time to be off that little bit (In the olden days, I was taught that 5% of my code was to actually do what you wanted it to do, and 95% of the code was to account for everything else that could possibly go wrong!)

The 83886.07 number is still fishy to me — I have a gut feeling that it is somehow related to the number of seconds in a day – 86400. And that when the time is off, it somehow subtracts the same number from that 86400 every time. (Again, back in the old days where more than once I accidentally coded a LOAD instead of a LOAD ADDRESS in assembler — results were ALWAYS unpredictable — there’s an old joke: Novice: What’s the difference between a Load instruction and a Load Address instruction?” Old Hand: About a week of debugging.)

I’m pretty certain it’s coding that is not expecting that time difference, but I haven’t been able to figure out how to contact Weather Underground support (Other than email, which I’ve never had them respond to)/ And they may not have the resources or time to debug and fix it anyway as it probably isn’t a common occurrence.

In the meantime, I will keep an eye on it.