PwsFWI

Introduction

The Fire Weather Index for a personal weather station, in short pwsFWI, is probably one of the most complex modules of CumulusUtils. Not so much for the calculations, which once you know what to do are not that complex, but more for the interpretation and understanding of what is shown. This Wiki article will try to explain both how the module works, what you get and the value of it.

This page is about the module from a practical point of view, you go to Theoretical background on pwsFWI.

For external reference on the theory behind the pwsFWI you can go the The Hot-Dry-Windy Index: A New FireWeather Index site of Michigan State University who adopted it as a tool for climatological analysis. The 2018 article on which I based the software is The Hot-Dry-Windy Index: A New Fire Weather Index. This is an open access article under the Creative Commons Attribution License.

The software is (c) Hans Rottier and is part of CumulusUtils also under the Creative Commons Attribution License.

Operation

This module is included in the website. When needed as a single output the following command is given:

  utils/bin/cumulusutils.exe pwsFWI

Output

The output consist of two or three files files:

pwsFWIcurrent.txt
pwsFWI.txt
pwsFWIanalyse.csv (optional, created if the inifile parameter Analyse is greater then 30)

pwsFWIcurrent.txt

This is the file of which the contents is shown on the left side of the menu bar when the website generator is used. User using pwsFWI as a stand-alone can choose how and where to use the contents of this file. It shows the current value of the Fire Weather Index as calculated at the most recent rollover.

pwsFWI.txt

This is the main output of the module containing both the calculations of the past days but also the prediction on the basis of the values of Yourweather.co.uk (see Forecast). It also shows the legend for the colour coded values.

NOTE: The values bear no relation to other fire weather indices (there exist others) but the colour coding does. The colour codes are not formally standardised but informally it comes close to standardisation.

pwsFWIanalyse.csv

Is a comma separated values file with the calculations of the number of days as set in the Inifile parameter Analyse. That number could take up all days in your dataset but be reasonable. It creates the possibility to make your own calculations and checks. This was an important tool during the calibration phase of pwsFWI.

Inifile parameters

   [pwsFWI]
   Analyse=90
   WarningLevel=5
   ResultFormat=beteljuice
   FireImage=true
   predictionURL=http://api.yourweather.co.uk/index.php?api_lang=en&localidad=185686&affiliate_id=52wzikfato88&v=2.0
   PredictionBackground=Moccasin
   CurrentIndexFormat=Standard | Betel-Kocher
   CurrentPwsFWI=
   CurrentIndexDay=Today