Using a PWS


#1

After having no precip recorded at the airport ~4 miles away, and having a brief downpour at my home this morning, I’m thinking of using a PWS that is in my neighborhood. What are some pointers to help in verifying their information is correct? Just keep an eye on the station and make sure it’s recording rain when it rains, temps seeming close… anything else? Is there a way to verify on the PWS website if this station has a lot of downtime, etc?


#2

I just recently switched to a PWS a week or two ago and I’ve just been checking it often to compare to the actual weather, especially on days when it has rained. If there is a better way to verify its accuracy I would be interested as well.


#3

I just watched a few of them that popped up around me for accuracy as well as up time. A couple would go offline or not report for days at a time. The one I’m set to now is pretty legit!

I will add that if you click on the “more info” in the “change weather station” area, it should take you to a website that breaks down the information reported by the PWS. What it is comparing it to, I am not sure, but it will also tell you if and when it has been offline or not sent weather information.


#4

Here’s another question I wonder about the weather aspect in general. Where are the forecast actually generated from? The airport and the PWS have different forecast for this next week. I’m just curious how a forecast for a PWS is generated? Why would a PWS say it’s going to rain 3 times this upcoming week and the airport 4 miles away says it will rain 1 time.


#5

@Modawg2k

Just a little food for thought…the extreme localization of a PWS can help improve weather intelligence for sure. However, the downside is that the data can be inaccurate and the reporting spotty.

I would say your suggestions, temperature, and precipitation, for accuracy, is excellent and easily measurable. Another suggestion for an accuracy test would be to monitor that station this week and see if you actually experience 3 precipitation events, as opposed to the one precipitation event the airport is predicting. After which, you will know how accurate that station is and whether it’s geographical location will suit your weather needs.


#6

I’ve used this in the past and it may have the station you are looking at for validation.

This article will help you find the PWS station online and get much more data regarding it.

:cheers:


#7

why am I not able to see all PWS in my area? Weather Underground shows a PWS near my house, but when I use “change weather station” option on Rachio app, I do not see same PWS.


#8

I just started looking into PWS today, but from another thread on here, seems like weather underground is a paid service so stations on there are not in the service that Rachio accesses. I’m not really sure what separates stations on weather underground vs other stations, but I know that a pws that is slightly closer to me is not in Rachio but is on weather underground.


#9

@George @franz Where do the temperature and rain forecast from PWS come from? In the examples below, I took screenshots of both the PWS nearby and the NWS station just 4 miles away. Note these differences

  1. PWS temperature forecast are about 15 degrees cooler every day than the NWS forecast. Also, the PWS forecast is way off since you can see it’s mid 90’s reading by both stations.
  2. PWS forecast a lot more rain than the NWS station.
  3. PWS shows a moon and NWS shows a sun, not sure if that matters

My main concern is that the my future forecasted watering schedule if using the PWS will always be way off and basically useless. I know that if the PWS is feeding accurate information, my flex daily will adjust, but it makes the calendar forecast pointless and I don’t like the idea of not having a somewhat accurate 14 day outlook for my watering. What do you guys think?


Arizona Monsoon Thunderstorms
#10

@Modawg2k

That is odd. I have never seen such fluctuations in weather data between stations. The data the station collects will come directly from the station itself. I see the station location on pwsweather.com and it’s in Phoenix; therefore, the weather should be somewhat similar. However, in this instance, it’s off.

My two cents would be to use KDVT. Maybe someone will interject and have something more to add. For now, I am a bit stumped. I apologize for not being able to elaborate more on this matter.


#11

@George @franz What about the issue that the precip numbers reported by the PWS on pwsweather.com is not accurately reflected in the moisture graph. That seems to be an issue with Rachio and how it retrieves information from the service provider you use. Even yesterday, the PWS reports on the website 0.01 and the Rachio moisture graph shows 0. So far, every day that I’ve used the PWS this week, the precip levels in the moisture graph are not the same as waht is reported on the pws website.


#12

@Modawg2k

Can you provide a screen shot of your moisture graph details and screen shot from the website of the PWS showing the weather discrepancy? We need this to provide information to our weather service provider.

:cheers:


#13

@franz here ya go. You’ll see that Aut 9th shows on Rachio for 0.19, the website shows 0.24 on Aug 10th, which is 0 on Rachio


#14

@Modawg2k

Looked at the data and can’t definitively explain it. We are correctly pulling precipitation for the 10th now, don’t know why it was being reported on the 9th.

If you see this behavior again let us know and we can pull more data at that time to see where the discrepancy is, and possibly forward to our weather service provider.

:cheers:


#15

@franz Thanks for checking. I went back to the NWS nearby for right now since the forecast is more accurate. I will probably check back with the PWS in the near future to see if that stuff is still happening


#16

Rachio uses the Aeris weather service, which doesn’t pull observations from sites only on Weather Underground.

If haven’t already seen it, Rachio has a good PWS FAQ here:


#17

Even more wackiness with Rachio pulling PWS information. Where did yesterday go?


#18

@Modawg2k

Thank you for bringing this to our attention. Support is currently working on a bug fix for an issue like this.

If you keep noticing irregularities such as this PM me directly.

Sorry for any inconvenience this might have caused. Thank you for your support!


#19

I sent a message along to support just to have an ongoing convo about this PWS in general, and he says that the server is located in China and the forecast/time issues I’m experiencing could be because of that. He’s reaching out to your weather service company for followup


#20

Followup and conclusion. Thanks to the fast work of Kyle with support, it was determined that when this PWS was setup with pwsweather.com, the user forgot a minus sign on longitude, thus using forecasted information from China. Everything was fixed and now this PWS has appropriate looking forecasts.


Rachio not importing the right pwsweather.com precipitation data