Using a PWS

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.

@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.

1 Like

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:

1 Like

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.

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.

@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?

1 Like

@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.

2 Likes

@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.

1 Like

@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:

2 Likes

@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

@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:

1 Like

@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

1 Like

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:
http://support.rachio.com/article/309-personal-weather-stations-aeris-and-you

2 Likes

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

@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!

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

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.

2 Likes

@Modawg2k

Thanks, Modawg2k. I was happy we were able to get this sorted out quickly for you.

AWTony (AerisWeather Support)
Aug 20, 1:21 PM CDT
Kyle,
The forced update of the stations profile data has occurred.
http://api.aerisapi.com/observations/summary/PWS_1539GAMBIT?client_id=41aTTmvKLxW1JxjL38pDA&client_secret=EZ5dIpj7Ucf4NIu4LyLHmqcteSjbNSRqk4vwIvpl&from=08/19/2016&to=08/20/2016&plimit=32&filter=allstations&query=count:2,mint:-999,maxt:-999
Note it may take up to 30 minutes for the caches to clear.
Let me know if I may be of additional assistance with this station
Tony
AerisWeather Support
http://support.aerisweather.com/

AWTony AWTony (AerisWeather Support)
Aug 20, 1:08 PM CDT
Kyle,
Looking at the station, it looks as if the user first added it to PWSweather, with an incorrect longitude (forgot the negative sign). I am forcing an manual refresh of this station’s data within the API which should resolve this. I will update once this has occurred.
Tony
AerisWeather Support
http://support.aerisweather.com/

4 Likes

@Modawg2k and @njhaley, are you two familiar with this site? http://cals.arizona.edu/azmet/
University of Arizona Meteorological Network

Don’t know if it is any closer to you, but there is a weather station called “Desert Ridge” you might want to check into. There’s a daily lawn watering guide. http://cals.arizona.edu/azmet/phxturf.html

This paper might be interesting: Converting Reference Evapotranspiration Into Turf Water Use

3 Likes

Thanks for the read. I try to follow the UofAs stuff when it comes to best practices.

2 Likes