Formulas

Hi Brian,
Just wondering what the actual formulas you use (or where they come from) for the following parameters please:
Cloud height
Cloud temperature
Air Density
Density Altitude
Absolute humidity
Vapour pressure

Regards
Guru

Hi all,
Anyone else know anything about these please?

Regards

Guru

Is this for WD custom tags,or?
It’s not very clear

Yes, but more so the formula behind the tag i.e( Rel hum = x/y * 5.6 e)

why do you want to know?

One…these formulae aren’t protected equations…Two… I would like to calculate these values for some of my historical data.

…ive got a feeling you dont get an answer on this…

Google is your friend.

Dont think google knows what formulas wd uses…

I would look at the NOAA all the formulas are there, They would be the ones NOAA uses.

Thats not the question, its which ones wd uses…

“Hi Brian,
Just wondering what the actual formulas you use …”

there is no need people to be so rude on this forum, Makada
why do you think I would not provide an answer?
the problem is it takes time to search for all the formuals for each question , in the code
and so when I have the spare time I will look at answering the post

Im glad your finally …ah nevermind…
I think its rude not to answer someone for three months, anyway, back to topic…

Actually it’s:

I’m glad you’re finally …ah nevermind

I am only 1 person though
I do try my best
to answer all the emails I get and forum questions and improve the programs across multiple platforms, which takes a lot of time
I am sorry that its not what you expect

A lot are here if you do a search:Absolute humidity Found three you were asking about in about five minutes…

HI all,

Not a major concern for me I just wanted consistency of results if I choose a formula (as there are variations for some parameters) that it matches or is close to the ones WD uses (since I will log them). Brian, you do a fantastic job and I appreciate your time whenever you get an opportunity to reply if it warrants one. Keep up the good work.

Regards

Guru

I suggest you use the published formulas and post if you find any significant discrepancies with WD (with the data to facilitate investigation).

Many of WD’s calculations (especially cloud height) have been published on this forum over the years, but it’s not always trivial to convert from computer code to a human readable formula.