Page 1 of 1

Fire weather calculations info?

Posted: Thu 04 Jul 2019 5:56 pm
by HansR
Years ago I used to calculate the Fire Weather Index with FWIcalc by Greame Kates (New Zealand) but apparently he dropped the software in 2014. I don't know of any real alternative. Does anybody have info on the methodology and the calculations involved? I am thinking of writing my own one way or another. But it starts with theory. Some articles, papers, books or whatever is useful. Thnx.


Re: Fire weather calculations info?

Posted: Thu 04 Jul 2019 8:30 pm
by BCJKiwi
Softrock may well have stopped development and support but the software still works.
Some updates are still provided - i.e. for win10 compatibility.

The current version is v10.5.2.109 ... latest.msi

Re: Fire weather calculations info?

Posted: Fri 05 Jul 2019 6:02 am
by HansR

Thanks a lot!!

Interesting that I was not able to find that page. Neither from the Arthur's Pass menu/homepage, nor from Google.
But still, do you know of any publication or possibility to actually get info on the theoretical background of that program? Did Graeme publish any of this?


Re: Fire weather calculations info?

Posted: Fri 05 Jul 2019 9:24 pm
by BCJKiwi
These are all the links that were provided by softrock that I am aware of.
FWICalc Important Notes.txt
Windows Installation MSI file: ... latest.msi
FWICalc CHM Help File:
FWICalc EXE file:
FWICalc Math DLL:
FWICalc Data DLL:
FWICalc Auto Updater: ... update.exe

I presume they all still work. Have not used mot of them.

Check here for a summary of the factors involved in the assessment of Fire indices. Note that different countries have different measures and criteria.

Re: Fire weather calculations info?

Posted: Sat 06 Jul 2019 9:43 am
by HansR
Hi BCJkiwi,

Thanks for the links and info. I downloaded, read and installed. FWIcalc is setup and running well within a short time. I am just as happy with it as I was seven years ago.

I implemented FWIcalc seven years ago and had a good discussion - with you as well - about the values and theory. Also Graeme implemented the Angstrom-indicator after a discussion by email with me. Unfortunately I had to abandon my station at that time - and lost my documentation - but am able to restart now. Hopefully for a bit longer. It's a pity Graeme stepped out, but fortunately his work done is not left completely orphanaged.

With the changes in technique (e.g. Raspberry and server based generation) away from everything PC-based, an adaptation of FWIcalc to those changes might be useful. FWIcalc is pretty unique in the PWS-world as far as I can see.

I will restart my research into the theory behind fire warnings as well, simply because it is interesting (and because of climate change it will be even more so). But the most important is the understanding of the theory it requires, in setting up a warning indicator (objectivation). Local situations are always different and an indicator in the Low Lands with water all around, although arithmetically the same, will behave very different from indicators in New Zealand, South of France or Canada. The FWI is probably the most global of all but it did not surprise me the Swedes made their own indicator.

Anyway, I have a start for my PWS-site and will start studying, may eventually even start a thread on FWI theory, and will publish the result on my site :)
Thanks again.


Re: Fire weather calculations info?

Posted: Sat 06 Jul 2019 9:57 am
by HansR
And btw, @BCJkiwi,

Since we are talking and you are a long-time member of the forum I bring in the following.

After restarting my PWS and re-entering this forum,I noticed a lot of new things: New releases (MX), new technology (Raspberry) etc... and when I had missed something somebody said : 'you must read [....]'. Yes of course, I know: RTFM. But there is an awful lot of text here on the forum and many items have become old or even obsolete. Many links don't exist any longer and overall I had the impression that cumulus and the community was a bit dying. For a real newbie it might be difficult to enter or even repulsive.

Looking beyond, it was clearly not a dying situation, but now, a month later, I think that maybe it might be useful to make a fresh start with the forum. With a fresh start I mean: archive old and obsolete items (maybe even the whole old forum) and restart with a refresh of the main topics of installation and accompanying scripts etc... The same holds for website interfaces. Restart with the same items (as far as required) and most important topics. Many old reactions and experiences could be summarised in short manuals.

All in all, a refresh would clean-up the forum (and remove dead links), focus on the important things and present cumulus as a real living application (which it is).

Has this been discussed before? Do you think this would this be a good idea?
Would it be worth to start [a thread on] this? It might refocus things.