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PwsFWI: Difference between revisions
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[[File:PwsFWI legend.jpg|center|none|PwsFWI legend.jpg]] | [[File:PwsFWI legend.jpg|center|none|PwsFWI legend.jpg]] | ||
'''NOTE: This Fire Weather Index is an original development and bears no relation to any other existing fire weather index and the resulting (absolute) value can not be compared to any of those. It is the resulting warning level which can be compared and which should be used.''' | |||
'''NOTE: The units as shown in the table are the units required used by the equations. Your units for your weather station may differ, conversions are implicit and non-configurable!''' | |||
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. | 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. | ||
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For external reference on the theory behind the pwsFWI you can go the [https://eamcweb3.usfs.msu.edu/HDW/index.html 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 [https://www.mdpi.com/2073-4433/9/7/279 The Hot-Dry-Windy Index: A New Fire Weather Index]. This is an open access article under the [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution License]. | For external reference on the theory behind the pwsFWI you can go the [https://eamcweb3.usfs.msu.edu/HDW/index.html 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 [https://www.mdpi.com/2073-4433/9/7/279 The Hot-Dry-Windy Index: A New Fire Weather Index]. This is an open access article under the [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution License]. | ||
The | The user interface has two formats: ''standard'' and ''beteljuice'' which, you guessed it, has been designed by ''beteljuice''. | ||
On my (HansR) blog you may read [https://meteo-wagenborgen.nl/wp/tag/pwsfwi/ several posts] on the pwsFWI but also on the other fire weather indices in the world notably [https://meteo-wagenborgen.nl/wp/2019/08/11/fire-weather-the-canadian-fwi/ the Canadian FWI]. This complex FWI is used in many places but it is so complex that it is not summarized in equations, but referenced by the articles. The complexity of this FWI was one of the main reasons to create pwsFWI. | On my (HansR) blog you may read [https://meteo-wagenborgen.nl/wp/tag/pwsfwi/ several posts] on the pwsFWI but also on the other fire weather indices in the world notably [https://meteo-wagenborgen.nl/wp/2019/08/11/fire-weather-the-canadian-fwi/ the Canadian FWI]. This complex FWI is used in many places but it is so complex that it is not summarized in equations, but referenced by the articles. The complexity of this FWI was one of the main reasons to create pwsFWI. | ||
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ResultFormat=standard | beteljuice (the format of the output) | ResultFormat=standard | beteljuice (the format of the output) | ||
FireImage=true | false (flames are shown at the end of the scale) | FireImage=true | false (flames are shown at the end of the scale) | ||
predictionURL=[your API string] (If this string is empty, no prediction is done, see [[Forecast]]) | predictionURL=[your API string] (If this string is empty, no prediction is done, see Forecast on how to [[Forecast#Yourwether|configure yourweather.co.uk]]) | ||
(Choose the XML API, address 2: “Address 2: XML file with the 5-day forecast and detailed information in 3-hour intervals”) | (Choose the XML API, address 2: “Address 2: XML file with the 5-day forecast and detailed information in 3-hour intervals”) | ||
PredictionBackground=Moccasin (background colour of the prediction lines) | PredictionBackground=Moccasin (background colour of the prediction lines) | ||
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CurrentPwsFWI= (this is not a setting but an operational content used by the software) | CurrentPwsFWI= (this is not a setting but an operational content used by the software) | ||
CurrentIndexDay=yesterday | today (the day for which the Current Value is shown) | CurrentIndexDay=yesterday | today (the day for which the Current Value is shown) | ||
Note that the title of this page is optional. In the Language file, under the section [PwsFWI] you will find: | |||
Title=A Fire Weather Index for personal weather stations (default) | |||
SubTitle=(See below the table for background) (default) | |||
If you empty these parameters they will not show and the space occupied by these lines will disappear. This has been introduced to accommodate users who wish to clarify to their users what page they are on, which may be useful in some modular or website cases. | |||
== Inner working == | == Inner working == | ||
The software 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:// | The software 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://cumuluswiki.org/a/Theoretical_background_on_pwsFWI Theoretical background on pwsFWI]): | ||
#The saturation pressure of the water vapour (P<sub>sat</sub>) using the August Roch equation | #The saturation pressure of the water vapour (P<sub>sat</sub>) using the August Roch equation | ||
#The Vapor Pressure Deficit (VPD) | #The Vapor Pressure Deficit (VPD) | ||
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'''This Fire Weather Index is about the risk of ignition and the ease of propagation.''' So I the colour/number output of the index says basically: high number (red and purple) : high risk, low number (green) : low risk. | '''This Fire Weather Index is about the risk of ignition and the ease of propagation.''' So I the colour/number output of the index says basically: high number (red and purple) : high risk, low number (green) : low risk. | ||
<span style="color:white;background:green;">Green: </span> Wood is wet to very humid and at the end of the scale the evaporation of the water content in timber is beginning. The wood is difficult to ignite. | <span style="color:white;background:green;">Green: </span> Wood is wet to very humid and at the end of the green scale the evaporation of the water content in timber is beginning. The wood is difficult to ignite. | ||
<span style="background:blue;color: white;">Blue: </span> The evaporation continues but no real dry conditions exist. The wood is still difficult to ignite but thin twigs might be used to assemble and start a fire. Propagation is not fast is any. | <span style="background:blue;color: white;">Blue: </span> The evaporation continues but no real dry conditions exist. The wood is still difficult to ignite but thin twigs might be used to assemble and start a fire. Propagation is not fast is any. | ||
<span style="background:yellow;">Yellow:</span> The evaporation is now speeding up and with wind it catches up. After some days the wood is easier but still requires to be lit. A spark would not be enough to ignite, propagation would still be slow. | <span style="background:yellow;">Yellow:</span> The evaporation is now speeding up and with wind it catches up. After some days the wood is easier to ignite but still requires to be lit. A spark would not be enough to ignite, propagation would still be slow. | ||
<span style="background:orange;">Orange:</span> The humidity of the environment becomes low, typically 40% or lower and the wood now really gets dry. Pools and soil dry out and undergrowth and litter become easy to ignite. With wind the drying process speeds up. | <span style="background:orange;">Orange:</span> The humidity of the environment becomes low, typically 40% or lower and the wood now really gets dry. Pools and soil dry out and undergrowth and litter become easy to ignite. With wind the drying process speeds up. | ||
<span style="background:red;">Red: </span> In the Red phase the relative humidity get to 30% or lower, the wood is dry and ignition becomes easy. Dead materials all have dried out and the stomata of the living plants have closed during the heat of the day. When this phase has a long duration sparks (electricity, lighting, stones hutting each other or human causes) may be a cause of ignition. | <span style="background:red;">Red: </span> In the Red phase the relative humidity get to 30% or lower, the wood is dry and ignition becomes easy. Dead materials all have dried out and the stomata of the living plants have closed during the heat of the day. When this phase has a long duration sparks (electricity, lighting, stones hutting each other or human causes) may be a cause of ignition. | ||