Programming Irrigation Using Today's Weather Forecast

[jmed999]

Now that we have weather forecasting as part of the irrigation module, I've been thinking about incorporating it into my irrigation programs. Has anyone else used today's forecast into their irrigation programs? If so how? Looking for ideas.

 

Thanks!

[MaddBomber83]

Well, I have the Irrigation module running as well to figure out what days to water.

 

On the days watering I also use predicted rain fall to not water on days it may rain.

 

I add predicted low to not water on cold days.

 

When the actual timers are running it will wait until wind speed is low enough.

 

 

If you are not using the irrigation module, you can instead flag a schedule to run normally, and add a second schedule that runs if it was hot.

 

You could also fake some irrigation items such as having your run time based on high temperature.

[jmed999]

Yeah, I have the irrigation module. I've been using programs and the irrigation module for a while now and would like to incorporate the forecast info.

 

What rain criteria do you use for today's forecast that will make yours not water your lawn?

[MaddBomber83]

24 Hour Rain. I have it skip the day if it will exceed one of my cycles unless I need two cycles.

If
       Time is 11:00:00PM
   And Module 'Climate' 24h Low Temperature >= 40 °F
   And Module 'Climate' Wind Speed <= 20 mph
   And Module 'Climate' Gust Wind Speed <= 20 mph
   And (
            (
                 Module 'Climate' Irrigation Requirement >= 0.2 inches
             And Module 'Climate' 24h Rain <= 0.25 "
            )
         Or (
                 Module 'Climate' Irrigation Requirement >= 0.4 inches
            )
       )

Then
       Run Program 'Irrigation Started' (Then Path)

Else
  - No Actions - (To add one, press 'Action')

[jmed999]

So you use predicted rain amount. I wonder how accurate this is. I would like to program based on the percent chance of rain...say over an 80% chance. Is there a way to do that?

[MaddBomber83]

You may be able to use intensity, Coverage or Condition in your logic.

 

But.... I don't think it is really necessary.

 

The irrigation module adjusts based on past rain already.

 

In the logic I use, if there is prediction for .2 inches or more then it will delay it ~ 1 or 2 days. The Irrigation Requirement builds up to .4 inches and then it doesn't matter if it is going to rain or not.

 

Going further, you can consider the value of the prediction to indicate the likelihood that it will happen. Some examples for my area:

0.05" Predictions almost never come true.

0.10" sometimes comes true.

0.20" almost always come true.

 

If your area is predicting that you are get 1 foot of rain in the next 24 hours, I think that gives you a high chance of getting at least a few inches.

 

So for your % chance, I still recommend you use 24 hour rain prediction. Just set it high enough with some trial and error so you get an 'accurate enough' schedule.

If you add a second threshold for your irrigation requirement that would override any prediction then you'll be set. If you get unlucky and your 80% chance of rain does not come for two days, your requirement would have built up enough that even 1 foot of rain wouldn't stop you!

[Waketech]

Sorry to jump in, just wondering what the irrigation requirement is set on. For example I have the following setup....

 

Water Available/Type = Silty Loam

Root Depth = 4"

Allowable depletion = 50%

Calculated Allowable depletion = 0.4"

The above calculates a water applied per cycle value of 0.5"

 

What would one set in the program for an irrigation requirement less than ?

 

Thanks

[MaddBomber83]

You'll want to read up on Using the Irrigation Module Here. While it says weatherbug a lot of that information is still applicable. Let us know if you have any questions after!

[jmed999]

You may be able to use intensity, Coverage or Condition in your logic.

 

But.... I don't think it is really necessary.

 

The irrigation module adjusts based on past rain already.

 

In the logic I use, if there is prediction for .2 inches or more then it will delay it ~ 1 or 2 days. The Irrigation Requirement builds up to .4 inches and then it doesn't matter if it is going to rain or not.

 

Going further, you can consider the value of the prediction to indicate the likelihood that it will happen. Some examples for my area:

0.05" Predictions almost never come true.

0.10" sometimes comes true.

0.20" almost always come true.

 

If your area is predicting that you are get 1 foot of rain in the next 24 hours, I think that gives you a high chance of getting at least a few inches.

 

So for your % chance, I still recommend you use 24 hour rain prediction. Just set it high enough with some trial and error so you get an 'accurate enough' schedule.

If you add a second threshold for your irrigation requirement that would override any prediction then you'll be set. If you get unlucky and your 80% chance of rain does not come for two days, your requirement would have built up enough that even 1 foot of rain wouldn't stop you!

 

 

Thanks! This is great info! I'm going to use some of this in my programs and hopefully save money My water bill here can be $200/month easy in the summer, mostly from watering grass.

[bipto]

You'll want to read up on Using the Irrigation Module Here. While it says weatherbug a lot of that information is still applicable. Let us know if you have any questions after!

Thanks - that's great info for those of us just getting started with this!

 

I do have one question...

 

How are you folks figuring out how much water your system is putting down? My system, for example, covers about 13500 sq. ft. using 27 heads distributed across 7 zones. Each head is currently configured to flow between 1 - 2 gpm depending on my "guess" of the relative requirements at its location, and each zone is currently run between 16 - 22 minutes depending on the amount of sun / shade it sees. Add to all of these variables the fact that all zones have varying degrees of overlap (all "points" are affected by at least two heads, but some see 3 - 4), and it seems that estimating a system-wide output with any accuracy would be nearly impossible...

[jmed999]

You'll want to read up on Using the Irrigation Module Here. While it says weatherbug a lot of that information is still applicable. Let us know if you have any questions after!

Thanks - that's great info for those of us just getting started with this!

 

I do have one question...

 

How are you folks figuring out how much water your system is putting down? My system, for example, covers about 13500 sq. ft. using 27 heads distributed across 7 zones. Each head is currently configured to flow between 1 - 2 gpm depending on my "guess" of the relative requirements at its location, and each zone is currently run between 16 - 22 minutes depending on the amount of sun / shade it sees. Add to all of these variables the fact that all zones have varying degrees of overlap (all "points" are affected by at least two heads, but some see 3 - 4), and it seems that estimating a system-wide output with any accuracy would be nearly impossible...

 

I used something similar to this...

 

http://www.amazon.com/Orbit-26250-Sprinkler-Catch-Cups/dp/B00CBZB8U8/ref=sr_1_fkmr0_1?ie=UTF8&qid=1403810205&sr=8-1-fkmr0&keywords=irrigation+peasuring+cups

[bipto]

I used something similar to this...

 

http://www.amazon.com/Orbit-26250-Sprinkler-Catch-Cups/dp/B00CBZB8U8/ref=sr_1_fkmr0_1?ie=UTF8&qid=1403810205&sr=8-1-fkmr0&keywords=irrigation+peasuring+cups

 

Ordered... Thanks!

[jmed999]

24 Hour Rain. I have it skip the day if it will exceed one of my cycles unless I need two cycles.

If
       Time is 11:00:00PM
   And Module 'Climate' 24h Low Temperature >= 40 °F
   And Module 'Climate' Wind Speed <= 20 mph
   And Module 'Climate' Gust Wind Speed <= 20 mph
   And (
            (
                 Module 'Climate' Irrigation Requirement >= 0.2 inches
             And Module 'Climate' 24h Rain <= 0.25 "
            )
         Or (
                 Module 'Climate' Irrigation Requirement >= 0.4 inches
            )
       )

Then
       Run Program 'Irrigation Started' (Then Path)

Else
  - No Actions - (To add one, press 'Action')

 

 

Shouldn't, "And Module 'Climate' 24h Rain <= 0.25" be greater than instead of less than? Edit* Never mind...I see what you did. Thanks agian!