PwsFWI: Difference between revisions

132 bytes added ,  26 March 2021
 
== Inner working ==
The inner workingsoftware is simply running through the daylist from the day where the user chooses to start: minimal 30 or higher if analysis is on. For each day an entry in the pwsFWI list is created and the following values are calculated (see [https://meteo-wagenborgen.nl/wp/2019/08/19/an-effort-for-a-simpler-fire-weather-index/ An effort for a simpler fire weather index]):
#The saturation pressure of the water vapour (P<sub>sat</sub>) using the August Roch equation
#The Vapor Pressure Deficit (VPD)
#The dayvalue for the pwsFWI by taking the product of the VPD and the windspeed.
#This pwdFWI fluctuatescan fluctuate pretty strong between days so some smoothing is done when takingaveraging the pwsFWI value and take the rain days over the previous five days into account which dampens the fluctuations up and down.
 
The result is the pwsFWI value for that specific day.
The output is then generated with the calculated list.
 
The value which is used for the user to display - the Current value - can be set to be today or yesterday (default) according to the value of the inifile parameter ''CurrentIndexDay''. Yesterday is the default because that is the last complete day and thus known (true) day. Today is still to be measured and therefore is a prediction.
 
For the output the chosen format is used with a warning level 5 or 6 depending on the choice of the user. 5 means a maximum warning level of '''Extreme''' (fire danger) and 6 means a maximum warning level of '''Catastrophic'''. '''Catastrophic''' has been added as a warning level in AutraliaAustralia some years ago. The warning levels have been calibrated (non-scientifically) during the first year and were correct according to other systems.
 
[[Category:CumulusUtils]]