Category Archives: Meteorology

About pwsFWI

pwsFWI is now a bit more than a year old and has proven its value : it relates very well to the existing indices and the EFFIS Current Situation viewer. This means that the note : Behavioural testing still under way! will be removed from the pwsFWI page at the end of the European fire season (21 September).

Having said that, I have noticed that some users have reverted to the FWI calculations and graphs as shown by FWIcalc  as if that one is better than pwsFWI.

Continue reading

On PyroLife ITN, Tecnosylva and Wildfire Analyst

This is a short blog on some fire related research and organisations. Unrelated directly to pwsFWI but definitely useful to follow if you are interested in fire – wildfire and/or society related issues regarding large wildfires. Especially the running webinars are interesting (and free) !

Recently (in  2019) an ITN project PyroLife started (what does ITN stand for btw?), led by Wageningen scientist dr. Cathelijne Stoof.

Apart from being a great initiative, it became quickly very interesting because of the free webinar which started 3 June 2020 (and running till the end of july 2020). The presentations of this Symposium are published on the YT channel of PyroLife (don’t start binge watching these presentations, prevent overkill).

I would like to point to the the presentation of Adrián Cordil of 10 June 2020 (at moment of writing not yet published) on thePyroLife YT channel linked above, scientist at the University of LLeida, Spain and associated with Tecnosylva S.L. (twitter account). He presented the work of Technosylva regarding simulation software, put to work in different parts of the world in the context of combatting wildfire situations.

Estimating Fire Weather is one aspect of this. An interesting piece  of software to look at is Wildfire Analyst also available for Android. Check it out.

pwsFWI is unfortunately not related to this [large] project, but the results of your weather  station, and your understanding of meteorology, definitely might give you an entry to understanding what they are doing there in Spain.

Impact of anthropogenic climate change on wildfire

I designed and developed my Fire Weather Index (FWI) for Personal Weather stations (PWSs) starting with basic logic reasoning (wet wood does not burn), with scientific background and made it usable in the context of PWSs. I found a very interesting and confirming article from October 2016: Impact of anthropogenic climate change on wildfire across western US forests [1].

Continue reading

Analysis of pwsFWI prediction

Introduction

In my previous blog I described why and how the predictions on pwsFWI were implemented. Also I promised a short analysis:

We’re now in version 1.8.3 and it seems all to be working OK. The testing is back on the meteorological level, trying to find out how much a two day ahead prediction will differ from the actual calculation when the day has past.

In this blog I will show the results and try to interpret them.
Please note that this is not a scientific or even a full analysis as I am lacking the resources and the data for that.

Continue reading

Winter is coming

Last night Daylight Saving Time switched back to its winter position. That itself is nothing special. Well, maybe it is because the EU is really thinking of abandoning the twice per year hour shift, it is biologically deregulating.

But that is not why I write this [short] message. The switch itself showed up nicely on the temperature graph of my weather station and, as if it was saying Winter is Coming, exactly on the time of the hour switch, the temperature fell from 15 to 10 degrees within an hour and a half.

It shows all nicely on the chart (after the break). Continue reading

Behaviour of pwsFWI with first rain

One of the goals of the current implementation of pwsFWI is to see its behaviour under all conditions. It is therefore very interesting to see that behaviour in the two stations in semi-arid zones (in Australia and in Spain) where long dry periods may suddenly alternate with rain after which the drought returns. Continue reading

Evaluating FWI for Personal Weather Station

In An effort for a Simpler Fire Weather Index I described my new FWI and the theory behind it. In short, this pwsFWI (as I have baptised it) is meant to be a generic FWI, valid everywhere and independent of geology and vegetation.

The pwsFWI is a (not too) complex measure of local meteorology, an indicator composed of humidity, wind speed and temperature. It fluctuates under ‘normal’ conditions and if it becomes dryer (a longer period without rain, the number becomes higher. As soon as it starts raining, the value starts dropping.

Continue reading

An effort for a simpler fire weather index

In this blog I will propose a fire weather index for PWSs. The goal is to get fuel parameters out of the equation. This means that species, litter type or geography, will not play a role as they do in the Canadian FWI. As such, it connects with a recent new development described by Goodrick et.al. 2 .

Continue reading