Trixology
WeatherCat => WeatherCat General Discussion => Topic started by: Michel on September 30, 2015, 07:19:02 PM
-
Hello all,
the CCC (with default rules enabled) will return "Heavy Clouds" for a calculated
cloudbase being less than a few hundred feet. This is (not just) a bit off the track
for the place I'm resident since my area suffers from temperature and dew point
being almost the same from early in the evening until late in the morning, accompanied by
a relative humidity of 96-99%.
During the past week every night has been absolutely clear. Unfortunately, the CCC
mechanisms drive the output to be "Heavy Clouds" under the above described
circumstances - at least w/o additional rules.
I thought about adding something related to solar radiation and barometric
pressure etc. but didn't come to a reasonable result, yet.
Has anybody tried to add some rule(s) to the CCC addressing (or even solving) this issue ?
Regards !
Michel
-
Michel:
I haven't really thought about trying to use solar radiation or barometric pressure in the CCC tool. I have just played around with adjusting the cloud base until it gives me a correct result most of the time. There are still some times when cloud base doesn't work very well for me. I will give some thought to using a rule that incorporates either "cloud base or solar radiation" or "cloud base and solar radiation". In the meantime, see the attached screenshot of my rules. By the way, I have added a rule for snow, which works for me because I have installed a heater in my rain collector cup.
-
[...] I have just played around with adjusting the cloud base until it gives me a correct result most of the time.
Thanks for sharing your CCC settings !
I'll try yours in my place and see how they'll work out here and perhaps fiddle around with them if necessary.
There are still some times when cloud base doesn't work very well for me.
I think taking the cloud base into regard only simply doesn't allow for drawing the right conclusions under all circumstances possible...
I will give some thought to using a rule that incorporates either "cloud base or solar radiation" or "cloud base and solar radiation".
I'm quite curious what you will come up with here.
By the way, I have added a rule for snow, which works for me because I have installed a heater in my rain collector cup.
Cool ! [tup]
I guess you use some kind of heating foil for that ? And some indoor power supply feeding power to it ?
What's the wattage of your heater ?
Regards !
Michel
-
I guess you use some kind of heating foil for that ? And some indoor power supply feeding power to it ?
What's the wattage of your heater ?
Davis sells a heater for their Vantage ISS units ==> http://www.davisnet.com/weather/products/weather_product.asp?pnum=07720
I have the power cable buried in a conduit. I added a relay to where it is connected to the mains inside so I can turn the heater on and off from my iPhone. Last year was my first experience with it and it worked very well. It was the first time I have had melted precipitation measured on the same day the snow fell.
I will get back to post something here after I get a chance to think about the cloud base issue. In the meantime, don't be afraid to experiment with the altitude in the CCC rules.
-
Davis sells a heater for their Vantage ISS units ==> http://www.davisnet.com/weather/products/weather_product.asp?pnum=07720
Thanks for the pointer, Blick. Seems to fit the Vantage rain bucket very nicely.
I think I'll go for a "standard" product, say something like this:
http://www.pollin.de/shop/dt/Nzg5OTQxOTk-/Bauelemente_Bauteile/Mechanische_Bauelemente/Sonstige_E_Geraete/Flaechen_Heizfolie_918_1.html?utm_source=google&utm_medium=pvgl&utm_content=850012&gclid=CL60gZvSn8gCFYUIwwodAfcNXA
I have the power cable buried in a conduit. I added a relay to where it is connected to the
mains inside so I can turn the heater on and off from my iPhone.
A cunning solution. I think I'll use a thermostat which will turn it on around 0C.
I will get back to post something here after I get a chance to think about the cloud base issue.
Thanks for taking the time on this issue !
In the meantime, don't be afraid to experiment with the altitude in the CCC rules.
I won't ! And I'll report the results (as soon as I'll get reliable ones or being at a loss ;-)
Regards !
Michel
-
Here's mine - my rules are set up to determine the most notable thing about the weather at any particular moment, so first there's the rain, after that comes wind, then solar and temperature followed by one for dampness (using the leaf sensor) and finally the calculated cloud-base.
You can see that currently, the dew is just starting to form for the night and it's calculating 'Damp'.
-
Stuart,
thanks for sharing your CCC settings too. They look like they will give a pretty good
description of what's up outside. Thanks for the inspiration !
Michel
-
Stu:
Thanks for sharing. I appreciate the explanation and have implemented some rules based on your post. Inserting rules for wind and sun before the cloudbase rules will help to have a more informative and varied set of conditions that just rain and cloudbase.
Michel:
The false condition I get the most often is when the CCC returns "Clear" based on cloudbase alone. I am experimenting with cloudbase and solar radiation. For example, if the rule requires cloudbase > 2500 AND solar radiation > 400 then it will not return "Clear" on a cloudy day. This does NOT work at night, because it will never return "Clear" if it is dark outside. But I don't care so much about cloudbase conditions at night because only Herb is awake in the middle of the night and he can't see the difference between clear and partly cloudy in the dark anyway.
This is not a perfect solution, but it is more accurate during the day than cloudbase alone. Because I have just started to experiment with this, I'm not sure that 400 is the right solar number, but I will watch it over the next several days and see if I can tweak it for accuracy.
-
I too set up a few new rules based upon Stuart's and your "templates".
See attachment for my first approach - remains to be seen what it's worth ;-)
Blick, see both of the last rules for output at night ;-)
Michel
-
I have now adjusted my rules after playing with them today. See attached. I like this much better than what I was doing previously.
-
Blick,
glad to hear you are happy with your latest CCC changes.
It's the same on my part after having applied the changes yesterday.
I like this much better than what I was doing previously.
Ayup, the old story... there's nothing which could prevent one from being
smarter today than yesterday ;-)
Regards !
Michael
-
I've been fiddling around with the CCC settings during the past weeks
and it seems I finally found a collection of settings which seem to work
reliably under the current autumnal conditions.
See attachment...
Just a few minor glitches in the morning time around 8am for 30-40 minutes
when it can't decide whether it's misty, foggy or whether there are heavy clouds.
It remains to be seen what these settings will result in in winter/summer...
Regards !
Michel
-
Thanks everyone for sharing these ideas for new rules - I've shamelessly stolen the ones I like and am tweaking them for the local conditions here. 8)
John
-
I spent my career in finance. We wrote something called a prospectus for potential investors to read about a specific company. Every prospectus in the world (at least the legitimate ones) are written in the same fashion. You obtain copies of every prospectus in your industry, take all the best bits you like, copy and paste and then edit slightly for your company.
That is a long explanation of how there is an honoured history of shamelessly "borrowing" the bits you like. That's why we have a forum.
Well done, mate.
-
You obtain copies of every prospectus in your industry, take all the best bits you like, copy and paste and then edit slightly for your company.
LOL!
I think that works in a lot of areas of life, from parenting to web design. :)
-
That is a long explanation of how there is an honoured history of shamelessly "borrowing" the bits you like. That's why we have a forum.
So what you're saying is that we're a community of practice as defined by http://wenger-trayner.com/introduction-to-communities-of-practice/ (http://wenger-trayner.com/introduction-to-communities-of-practice/) and not merely a collection of plagiarists. Have I got that right? ;D
And you've reminded me that I've got some student assignments to feed through the plagiarism checker...
John
-
Just remember, John, that if a student copies off of one person, it's called plagiarism, but if a student copies off of a lot of people, it's called research.
Fine line :)
Edit: I forgot to say that I spent some time editing the CCC as well. I went a little more granular than my wife would have. All she would put in would be: (50F> Return 'Freezing')
-
I just wanted to bump this thread to ask again how the CCC works with a Davis unit.
My current condition is "Clear" but that isn't in any of the rules I've set up. Where is WXCat getting the "clear" condition from? I'd rather set up some more rules, like Sunny, or have it say HOT! but for now, I'm just getting clear. (For the record, it is currently clear).
Thanks.
-
]I've only made very minor (I think( edits to the default rules. I'm pretty sure there was already a rule in my install. OTOH, I may have
stolenborrowed these rules from others! [blush] Here is a list of the rules affecting 'clouds'. "CB" is "Cloud Base", of course. The rules are checked from the top down. The first one that returns 'true' is what gets used.- If CB > 4500 ft Then Return 'Clear'
- If CB > 4000 ft Then Return 'Scattered Clouds'
- If CB > 2000 ft Then Return 'Light Clouds'
- If CB > 1500 ft Then Return 'Cloudy'
- If CB > 600 ft Then Return 'Overcast'
Only 'work' I remember doing was an attempt to create a rule for "fog". Never found one that worked. Perhaps "If CB < 10 Then Return 'Fog'"? I think I was trying to use Humidity...
-
Ok, I'll check my reading comprehension next.
I see I had a rule of cloud base > 4500ft = Sunny. That was too high up the list and over-rode most everything else. Changed. Thanks!
Now I just wish we could have multiple, or at least, two, conditions active at the same time, i.e. Muggy & Hot, Cold & Damp, etc.
dfw
-
I doubt you'd ever see "Cold & Damp" in Dallas (even on the north side). "Muggy & Hot" would probably burn into the monitor, even an LCD type! [removed link to the now castly photobucket.com site]
-
Now I just wish we could have multiple, or at least, two, conditions active at the same time, i.e. Muggy & Hot, Cold & Damp, etc.
You can just enter a rule that states If Ext Temp > 85 AND Ext Hum > 85 Current conditions are Hot & Muggy. If both condition are not met, it drops down to the next rule, which would just deal with temperature or humidity. It takes more rules to do it this way, but you can end up with exactly the multiple conditions you want. You just have to think through where they are placed in the rules order, because the first one that meets all the conditions wins.
-
Dear dfw and WeatherCat tinkerers,
I just wanted to bump this thread to ask again how the CCC works with a Davis unit.
My current condition is "Clear" but that isn't in any of the rules I've set up. Where is WXCat getting the "clear" condition from? I'd rather set up some more rules, like Sunny, or have it say HOT! but for now, I'm just getting clear. (For the record, it is currently clear).
Thanks.
The rule that generates clear is one of the default set. Here is what they look like on my WeatherCat installation:
(http://www.canebas.org/misc/Capto_images/WeatherCat%20Current%20Conditions%20Calculator%202016-08-11.png)
Can you scroll up to those rules? The Current Conditions Calculator runs through all the rules from top to bottom and returns the first rule that is true. So if you don't want the default rules (which generated the 'clear' in your case) you should either delete them or move them further down.
You can read up on how the Current Conditions Calculator works starting on page 85 of the WeatherCat manual.
Cheers, Edouard
-
Thanks Blicj11! I'll do that!
-
Here is my current set of rules.
-
It would be cool if there would be an option to >export< those rules into a text file. Another thing to be cool: Duplicate a rule so that there is no need to build every new rule from the scratch.
;)
-
The "Current Conditions Calculator" is very useful and has a lot of power, but the more I look at the "Current Conditions Calculator", the User Guide, and the examples in this thread, the more questions I have.
What names can we use? Where are they listed? Are they the Channel names (User Guide page 84)?
Can we use the AppleScript tags in the Current Conditions Calculator?
What about "CB"? Where does that come from? Are there other hidden terms that we can use?
Does "Rain" really work or should it be "Precipitation per hour"? Or maybe "Niederschlag/Stunde"?
What about the units? Can they be metric or english or mixed? What is the syntax? EG "in/hr" or "in/h" or "inches/hour" or "mm/hr" etc?
Is the syntax "If <name> <symbol> <value> Then Return <string>?
How rigid is that? EG what if we drop the "Then"?
It's quite possible to write a complete set of rules in the Current Conditions Calculator and never know if they all work. Is there any way to test them?
-
A bunch of questions! And no numbers! :P [lol]
However, most of them seem to be answered by just using the Edit or New button to get the CCC dialog window. There are up to three WC values you can use, whatever is in the pop-up menu next to the "If".
The "Then" looks to be pretty well hard coded. It's between the third (optional) condition and the "Current Conditions Are:" text box where you enter whatever you want the output to look like.
The values of the units will be whatever you have in the WC prefs.
As for 'testing', there is a "Current Result:" output on the main CCC window. Just below that is a text box where you can manually enter values that can then be tested by the rules. I'll have to assume The Manual has info about how to enter those values as I have never tried.
The most important question, to me, anyway, is how "CB" is calculated. I assume (I know, I know!) that it involves the Humidity and/or Dew Point and the Temperature. I further assume that the calculation assumes a standard rate of temperature with altitude and a "standard" rate of change in the humidity and/or dew point (is there is one). It's probably in The Manual? [banghead]
As is often the case, when all else fails, "Read the Manual"! To wit:Calculated cloud base is derived from the air temperature and dew point and gives an approximate indication of the base of cumulus[emphasis added] clouds.
Further re-enforcing the Cumulonimbus term, "CB", rather than "Cloud Base" in general.
-
- You can name your current condition result anything you want
- You can select any weather variable that is included in the pull down list
- You can include any synthetic channel you have defined
- You can use either Daily Rain or Hourly Rain
- Units are automatically based on the item you select from the pulldown menu
- The examples posted in the forum are not the correct syntax for calculating the condition, they are just the name of the rule, which you can name anything you desire
You can also use WeatherCat's Apple Script interface to set current conditions.
The calculation for cloud base is derived from air temperature and the dew point and is a theoretical indication of the base of cumulus clouds. The most common formula is:
- Calculate the difference between the external temperature and the dew point.
- Divide the spread by 4.4 (if temperatures are in ?F) or 2.5 (if temperatures are in ?C), then multiply by 1000.
- Add the result from step (2) to the Field Elevation to get cloud base ASL (Above Sea Level)